First, it is rarely necessary to provide cover plates over a butt splice weld if the weld is done properly.

Next, the ends are initially cut square, but then are prepared to receive a complete joint penetration weld by a welder who is qualified to make such welds. In the US, the joint configuration can be either pre-qualified (meaning that it fits one of the many standard joint configurations) or it can be separately qualified by testing. Assuming the joint configuration is pre-qualified, then the next necessity is to have a Welding Procedure Specification that lays out the sequencing, size and type of weld to be used in that joint. Then the welder has to be qualified to the Welding Procedure Specification in the proper position of welding (flat, horizontal, vertical upward or downward, and overhead), using a particular welding process (gas metal arc welding (GMAW), flux core arc welding (FCAW), gas tungsten arc welding (GTAW) or the more common shielded metal arc welding (SMAW)), with a particular filler material (electrode) with the weld properties and position compatibility that you need.

All of these are laid out in the American Welding Society's codes and standards, the most common of which is AWS D1.1, Structural Welding Code- Steel. There are other welding requirements depending on the country you are in.

The purpose of the complete joint penetration weld it to achieve a splice that develops the full tensile strength of the member being spliced.

The completed weld should then be inspected and tested for compliance with appropriate standards using acceptable nondestructive testing methods such as ultrasonic flaw detection, radiography, or others as appropriate to the application. Rejected welds must be removed and the process repeated.

In most steel design, we don't consider heat affected zones affecting strength like in aluminum.

Very well said, Ron!

Pictures worth a thousand words:

This is a wide flange that is cut square and spliced.. we put cover plates on the web. But I told the contractor the main strength region of a wide flange is in the top flange and bottom flange..

Images showing the top and bottom portion of the wide flanged spliced welding at the web:




This is at the back of it. Is it considered full weld?



Whatever. I told them the flanges are the real meat of a wide flange where tension and compression can occur and told them to put metal plates on them too. What you make of this advice? Putting cover plates on the flanges would indeed make it sronger, wouldn't it.

First, you need to find a welder. Whoever made those snots on the beam can hardly be called a welder.

Best regards - Al

Agree with GTAW....those are some lousy welds. Also, from what you have shown, they are fillet welds on a cover plate that was maybe used as backing for a complete penetration weld. In any case...get a qualified welder.

Can you show pictures of the difference between fillet welds and complete penetration weld? In my place. ALL Welders are just ordinary workers who weld... maybe former masons or carpenters who need to make a living. They are not trained in any welding school, and there is none here. This is why some architects avoid steel structure because they are afraid of welding quality.

Btw.. the last picture shown above (reproduced below) are not fillet welds on cover plate.. they are supposed to be full penetration weld on the main beam as shown. Are they not? But they look bad (or missed it) so I told the contractor to go back and do more full weld as well as put cover plate on it.



Again, are these not deep penetrating weld? What are these supposed to look like? Thank you.

A few examples below. The welds you show suggest the welder has no idea how to set the welder nor do they understand when he is or is not getting correct penetration.

https://www.google.ca/search?q=good+welds+vs+bad+w...

The weld you show above is a very poor attempt at welding a complete penetration butt weld. There appears to be no joint preparation, no space between the two piece to be joined and poor technique in the welding. With this type of poor joint preparation, even a good weld would not penetrate the thickness of the web.

The fillet weld you asked about is on the cover plate on the opposite side. The welds are equally poor there.

The welding you've shown for this splice is dangerous.

So it's better to have wide flange splices connected with bolts and cover plates? I'd have the designer designed them instead of relying on welding.. so it's ok to have additional cover plates with bolts added to any existing welding (pretending the welding is not there)?

The welding methods were done to over 90% of steel structure in my country. We don't have school for welding.

The welding rod used is 6011.. what is your thought of 6011?

edit.. I plan to have the following (image is just sample from web) added and designed.. but why is there only 3 bolts in the web on one side? Why aren't there bolts in the other side of the web?

Because the connection is shown with the web plate welded one side, bolted the other. This is often done with the flange plates as well. Considering the quality of the welds you showed, perhaps you should use bolts both sides on all the splice plates.

Yes. We will.. Is it easy to drill thru 10mm of flange thickeness (in the field)? How hard or easy is it? Can a normal drill machine be used or a huge one? What are others experience on this?

It needs to be a heavy duty drill, magnetic if possible. This one would do it.

http://www.bosch-professional.com/za/en/gbm-32-4-5...

According to the welder who did the above weld, it's not the direct weld but the other side of the full penetration weld.. the web is 0.250 inches (6.5mm), so when he did the full weld on the other side, it affects the side shown above. Why, what is supposed to be the appearance when your weld penetrates to the other side?

Just took a couple photo's recently, this is what a full penetration weld should look like. You can also see a proper joint preparation in the first photo.

What city are you building in?

The welder did a back job. Here's in its completely (why is the portion in white?):



Again, this is the back of the front full weld.. so apparently the weld has fully penetrated into the other side. I need more clear pictures of what the other side should look like. Maybe proper joint preparation makes the other side nice and smooth too?

If it were my job, I would politely tell the contractor that the welder should not work on the project again. Even his repair looks bad.

What kind of welding rods do you use for deep weld? We use the so called 6011.. here's what it says:

"The 6013 electrode is often used in situations that involve irregular or short welds that require a change in position because it provides a very stable arc and a smooth finish. The 6011 electrode is often the better choice on painted, dirty or greasy surfaces when appearance is not as important and more penetration is needed.

Read more : http://www.ehow.com/info_8087713_difference-rod-60..."

This is another weld on other wide flange splice that is direct.. it is satisfactory?




Has it more strength if the splice in the web has horizontal weld than simply cutting the wide flange and welding it square?

Your welder is full of crap! The weld you showed is not the "back side".

As for the electrode, an E6011 electrode is a penetrating electrode that can be used in all positions. It is a versatile, "all purpose" electrode. It provided deeper penetration; however, it also yield greater porosity and slag inclusions that can lead to nondestructive testing rejection. The welder must know how to use this and other appropriate electodes for the application.

The welder is a senior who welds 50-storey high rise. Our welder average salary is $15 a day working 10 hours. They don't even eat breakfast because no money. I wonder if welders in other places are richer.

I plan to subject it to x-ray testing. How reliable are x-ray testing and have you guys done any of these? Can you share any picture of the x-ray of the weld?

sedonas, I don't have much experience with x-ray testing, but I believe the results are only as reliable as the person interpreting them, which takes some experience to get right.

May I ask what part of the world this project is located.

Canpro.. Indonesia.

So backside of welds should look the same as the front?

Those of us in North America will have difficulty wrapping our heads around this problem. In North America, whom does what weld is governed by rules. Welding is a trade and one must go to school, and apprentice before being certified by whatever association they are registering with. Yes, welders are paid higher in North America. My nephew welds in the oil field and he has made upwards of $120/hr. He does work the same hours. That said, he would never show a picture of such terrible welds. I would not step foot into a building containing welds by that character if he is building anything larger than a dog house.

The comment from ehow is terrible. Weld regions must be prepped before welding. Paint, dirt or grease must be removed with a wire brush or grinder before welding. That is what the welders helper does. If you see a welder trying to weld thru paint or grease, grab a stick and give him a whack.

I wouldn't bother with testing until the welds look better. You will find all sorts of inclusions and slag based on what you have shown thus far.

All the wide flange were first painted at the shop and rust primered before delivery so yes all have paint on them. The welder directly welds on the welded parts without doing any preps. Let's say they are not dirty and no grease but only have paint.. won't the thousand of Fahrenheit temperature of the weld evaporate those paints away? Or would it be like zinc on galvanized steel where the zinc can affect the penetration of the weld?

Generally there is nothing in paint that is beneficial to the weld. There are components in the weld, i.e., hydrocarbons, that can introduce hydrogen into the weld. Hydrogen can cause delayed cold cracking. Other compounds can cause porosity and if the paint is thick, can interfere with proper fusion between the molten weld metal and the adjoining painted base metal.

As mentioned by others, the base metal has to be properly prepared before welding. Since these are suppose to be complete joint penetration groove welds, the base metal should have been beveled to permit proper joint penetration. All paint and other contaminates should be removed from the groove and the adjoining surfaces (1 to two inches from the edges of the groove). The welder can weld from one side, in which case he could have used a backing bar to support the molten metal as he deposited the root bead (first bead deposited). If the joint is to be welded from both sides, the first side would be welded and then the second side would be back gouged to sound metal before welding the second side. Back gouging is an operation where the welder uses a grinder (or other means) to remove the unfused metal to a depth where sound metal is found (from the weld deposited on the first side). The back gouging operation ensures the welder is depositing weld on good sound weld metal and not simply depositing weld metal over slag.

All of this discussion is meaningless unless there is a skilled welder available to make the welds. When there is a question about availability of skilled welders, a bolted connection is a valid option.

Best regards - Al

For a wide flange w8x21.. is there a table how to put the bolted connections for square splice that would give the same moment and shear strength as the original section? How many bolts per side.. spacing and the size of the bolts?

Xray on this crap will give no workable results, as the surface is too irregular. Nor will any other type of ndt, for the same reason. This should be done by a "coded" weldor, and with hi-quality, low-hydrogen rods. Google for farm code pdf, this fits right in.

By the way, pay nuts, get monkeys. $15 a day?

Agree with KingNero....radiography will fail this weld. It has improper profile, incomplete fusion, poor penetration and no doubt, slag inclusions. That would make it fail essentially any radiography criteria you apply to it.

Further, the fit-up is poor. The flanges are offset and warped.

Just because your welder has welded on high rise projects doesn't mean anything. He's obviously not very good at it and I would suspect any weld he has made on those high projects!

As for welding wages....most welders in the US are required to be certified and make a lot more money than that.

The following is really backside.. it's not direct weld on the 0.250" (6.5mm) thick web:



I argued with the welders and even nearly quarelling with them. They said it's backside and the weld got thru the 0.250" thickness. They use 6011 on the front side which is this picture (before coverplate was put):



The first earlier image is the back side which shows weld drops.. isn't it just the excess welds pushing thru to the backside?


Won't the 2 images above (front and backside) show that there is full penetration from the front side to the first backside piture with drops?

I need to know details so I know how to argue with them.

This is the standard technique of welding in my country so I'll learn what is proper and review it. Thanks.

Just because you have full penetration through the cross section does not mean you have a good weld! There are numerous criteria that define a good weld....complete penetration is not one of them. If your radiographic testing is as incompetent as the welding, then you probably won't know that you have a bad weld!

gtaw wrote:

Quote:

Generally there is nothing in paint that is beneficial to the weld. There are components in the weld, i.e., hydrocarbons, that can introduce hydrogen into the weld. Hydrogen can cause delayed cold cracking. Other compounds can cause porosity and if the paint is thick, can interfere with proper fusion between the molten weld metal and the adjoining painted base metal.

It's not exactly paint.. but epoxy primer.. the steel sections were epoxy primered before put in place. It's difficult to put epoxy primer when the structure are already in place. So my concern is not exactly paint.. what's the behavior of epoxy primer when it's on steel and they are welded.. would the epoxy just evaporate? Would some part gets into the weld? I need to know this important because we were installing purlins below the wide flange.. Should I not let the purlins be epoxy primered before putting in position? The purlins will be connected to below of the w8x21 distance every 0.6 meters.

Time to make a decision. The workmanship in your country and this groups is fundamentally different. It seems you have very few rules in your country, so why our opinion matters is confusing. Frankly, if I worked in your country and was to accept the same degree of liability we do here, I would find a new profession.

Someone asked here how the steel got from factory to welding. In our country. Steel sections were distributed in factory. I just visited one this morning when I made the order requested by the designer.



Here are the vertical C section that will be connected below the wide flange which would act as bracing.



As you can see. All the steel stocks of the company are not primered in any way but bare steel. So should we first primer it before welding it.. or should we weld it first then primer it (this will be more difficult as the worker has to climb every steel section). We can't primer it then grind away the primer in the welding region because that will put me in quarelling mode with contractor for delaying the project so much.

The welders who did the wide flanges have left already. They have zero warrantee or liability. The old contractor has no liability either. So it's up to me and senior designer to reinforce the sections.

Now I need to know something specific.. how does epoxy primer interact with bare steel and welding? Couldn't it just evaporate? Do you consider epoxy primer as paint? What part of paint can affect the weld? Does the epoxy primer has the same component as the paint ingredient that can affect the weld?

Thanks for those very helpful assistance. Your opinions much appreciated because the laws of physics is the same in different countries. This is the last time i'll allow any welding after this wall cladding support welding job.. after that. I will never trust local welding again and will never do steel sections again but only reinforced concrete due to the substandard quality in my place.

The initial photo you've posted seems to show no weld of the top flange whatsoever, unless my eyes are deceiving me. It looks like the welder merely butted the two pieces of wide flange together without any gap between them, and with no attempt to prepare the joint, and then deposited a very ugly partial penetration weld on the web only.

The top and bottom flange need to be full penetration welded for the member to have any meaningful strength!

It looks like the welder went back and simply dumped some weld metal on the top and bottom surfaces of the top and bottom flange where the pieces had been originally butted together without a gap between them. There was no attempt to grind a groove or bevel at that joint. That is not a full penetration weld! Regardless what type of electrode is used, you will only fuse the very top and bottom of the joint in each case, leaving a large gap of unwelded steel in the middle.

The welder is obviously untrained and unguided, and the situation is very dangerous. For each of these bad joints you are seeing, there are probably ten that you haven't noticed yet. Even if you fix the problem by reinforcing the splice joints from below, you need to do a thorough inspection of the rest of the work- every other weld this "welder" did.

There are primer paints that are intended to be "weld through". They are designed so that they do not leave a residue which is damaging to the deposited weld, though they can still generate some porosity or other flaws. They are just primers, and are not very durable- they provide little meaningful corrosion resistance beyond the erection period.

EPOXY is NOT a weld-through primer! If there is epoxy on pieces of steel, you MUST remove it by grinding for a sufficient distance on either side of the welded joint before you weld, or else you are very likely to generate flaws in the weld.

moltenmetal.. thanks for the input.. i'll get an expert welder to repair it... can it work if he would grind a bevel to the top and bottom flange of the present incomplete weld and do full penetration weld on it?

I have argued with the old welder crew so many times. I told them the flanges of wide flanges have tension and compression zones.. they don't understand what I'm saying.. they only focus on the web.. and they don't use any grinder but only acetylylene to cut steel.. this is the reason why I wrote this thread to ask if the flanges are as important as web. I'll also ask the contractor to read this message.

Their reasonings is that the thin 0.07" or 10mm can be penetrated by the 6011 electrode and automatically do full penetration welding because the flame reaches the other side. But then is it not true that if the welding can melt the entire 10mm flange.. it can fuse them from the outside? Why.. does it have to be filled up for any fusing to work at all?? Please answer this because this is my most important question. Thank you!

Is your weldor trying to do each weld in one pass?
What is the welding machine they are using? What are the settings?



The flux etc needs to be cleaned off for proper inspection.

Here is Lincoln Electric's basic video about visual weld inspection. It is aimed at Boy Scouts getting their welding merit badges.
https://www.youtube.com/watch?v=Ncguc7THEUY
I think the "welder" needs at least to spend a few days running beads flat and vertical and making pad welds on 10 mm material to achieve at least basic proficiency. Even then, I don't think he should be allowed to work on your job again.

I think the "expert welder" is going have to do a LOT of grinding or arc gouging to fix those welds. And probably cut out and replace some sections entirely.

Pages 32 thru 33 here discuss a minor case of one of the obvious deficiencies of those welds you are having to deal with.
http://supplier.huntingtoningalls.com/sourcing/doc...
Note the corrective action of cleaning the weld area.
The lack of cleanliness is NOT causing most of the problems however.

I envision the beam welding requiring be done in 3 different positions. Flat, vertical, and even overhead.

Here is a video showing some very good "vertical up" welding in process, and proper surface and edge preparation for 3/8"/~10 mm plate. Full penetration welds generally require some beveling or other edge preparation and multiple passes. They are NOT done by blasting thru the material in one pass.
https://www.youtube.com/watch?v=1QxT7JUjs94
Overlook the extremely uniform weld surface appearance. There is some leeway there.
Can you see how the weld completely fills the space between the plates, and fuses completely with each plate?

here is another series, from Lincoln electric. OK, but they spend too much time recording far away.
https://www.youtube.com/watch?v=oCS9t2CB6Vg

They are all using 7018 electrodes. As I recall the flux removal is much easier than 6011.

But notice the uniform bead, slightly convex, fusing with each side of

"Full penetration" joint in flange and web. Nacker strips left in place.
http://weldingweb.com/attachment.php?attachmentid=...
============

1:28 " the weld on the left there is obviously just crap"
https://www.youtube.com/watch?v=JEFd56ofHos

=================

This is >> generically << what a bolted I beam splice looks like.
http://i51.tinypic.com/2nlfgvb.jpg

There should be some serious engineering behind it.

Quote:

Is your weldor trying to do each weld in one pass?
What is the welding machine they are using? What are the settings?

I don't know the setting. They probably just estimate spark intensity. The old welders won't be back because in our place.. once welders got the money.. they never got back because the money is only good for a week for their family then they are broke again. Yes they are that poor. This is true for 99% of welders in my country.

Well. For the next welder who will repair the splice. I have to verify every step he made. For a 10mm flange thickness.. what is the usually the size of the bevel?

The old welders spent 1 day trying to add welds to half inch of gap for rafters than frame into the wide flange body.. imagine connecting web to web perpendicularly.. good it is on top of column so not hanging.

How big a gap before you can fill it with welds? They spent one hour just trying to build welds for each half inch (12.5mm) gap. They probably ignored the flange thinking the main support of wide flange are in webs.. so they focus on webs mostly.

Thank you all for the urls and videos. Will study them so make sure the repair team will do it right. Again. What is the usual bevel size for full penetration weld.. any table for given depth or thickness and bevel size?

Quote:

The flux etc needs to be cleaned off for proper inspection.

Here is Lincoln Electric's basic video about visual weld inspection. It is aimed at Boy Scouts getting their welding merit badges.
https://www.youtube.com/watch?v=Ncguc7THEUY
I think the "welder" needs at least to spend a few days running beads flat and vertical and making pad welds on 10 mm material to achieve at least basic proficiency. Even then, I don't think he should be allowed to work on your job again.

I think the "expert welder" is going have to do a LOT of grinding or arc gouging to fix those welds. And probably cut out and replace some sections entirely.

Pages 32 thru 33 here discuss a minor case of one of the obvious deficiencies of those welds you are having to deal with.
http://supplier.huntingtoningalls.com/sourcing/doc...
Note the corrective action of cleaning the weld area.
The lack of cleanliness is NOT causing most of the problems however.

I envision the beam welding requiring be done in 3 different positions. Flat, vertical, and even overhead.

Here is a video showing some very good "vertical up" welding in process, and proper surface and edge preparation for 3/8"/~10 mm plate. Full penetration welds generally require some beveling or other edge preparation and multiple passes. They are NOT done by blasting thru the material in one pass.
https://www.youtube.com/watch?v=1QxT7JUjs94
Overlook the extremely uniform weld surface appearance. There is some leeway there.
Can you see how the weld completely fills the space between the plates, and fuses completely with each plate?

here is another series, from Lincoln electric. OK, but they spend too much time recording far away.
https://www.youtube.com/watch?v=oCS9t2CB6Vg

They are all using 7018 electrodes. As I recall the flux removal is much easier than 6011.

But notice the uniform bead, slightly convex, fusing with each side of

There are others here much more knowledgeable in structural welding than I am, so take their advice first- but seeing the pictures you've posted has me worried- you need to take care of this!

With two pieces of 10 mm thick steel butted tightly together without any additional field preparation, there is no way you can deposit a reliable full penetration weld. If you want metal from the welding electrode to flow into the joint, you need space for it to flow into- otherwise, you are trying to use a stick welder to do an "autogenous weld" (where the parent metal of both pieces is melted together and fused)- that just plain doesn't work. Just because you see "burn through" at the other side of the joint, does not mean you have deposited a sound, full penetration weld at every point in that seam.

It is my opinion that the right preparation for this weld would be to bevel both pieces on an angle with a grinder from the outside, leaving a vee shaped groove all the way along the joint, leaving a small root gap between the two pieces at the point where the edges meet. The other option would be to try to do a partial penetration weld from both sides, grinding out the root of the 2nd weld after the 1st is completed to get a clean surface on which to carry out the 2nd weld. However, to be sure you did this properly, you would still need to do sufficient grinding so that you ensured you got a full penetration weld at the point you can only reach from the outside, i.e. the point where the web joins the flange. The vee groove and completion of the weld entirely from one side is just easier.

If the welder is worried about burning through at the root, leaving a mess, then a backer strip can be used. However, the presence of the backer strip makes it difficult to inspect the root of the weld. A good welder would not need one, but depositing the weld on the lower flange in place (i.e. welding 100% overhead)takes considerable skill and practice.

Any of these processes are beyond the skills of the person who attempted to weld this mess in the first place. You need a real welder, trained and qualified, to do joints like this.

Quote:

There are others here much more knowledgeable in structural welding than I am, so take their advice first- but seeing the pictures you've posted has me worried- you need to take care of this!

With two pieces of 10 mm thick steel butted tightly together without any additional field preparation, there is no way you can deposit a reliable full penetration weld. If you want metal from the welding electrode to flow into the joint, you need space for it to flow into- otherwise, you are trying to use a stick welder to do an "autogenous weld" (where the parent metal of both pieces is melted together and fused)- that just plain doesn't work. Just because you see "burn through" at the other side of the joint, does not mean you have deposited a sound, full penetration weld at every point in that seam.

The above was exactly what the welders want me to believe.. that my using the powerful 6011 electrode.. they can fuse the 10mm thick steel even without any gap for the metal from the welding electrode to flow to..

They said the welding arc melts the entire 10mm from one side and the filler filled it up even if no gap..

But we not into welding thought it was logical the welding can melt thru 10mm and fuse them.. but theoretically why doesn't this occur? Let's consider a welding electrode without filler.. if you touch the 2 pieces boundary without gap in them.. if the welding is very powerful. won't it melt the 10mm thick metal and somehow fuse them? Is it a limit of welding machine that makes this not possible... maybe there are very high tech welding machine that just can do this? What principle avoids it if not at all possible at all?

If I can't find local expert to repair it. I may bring in international welder to fix it.. but there is only 4 splices so the cost may not be friendly.. Hmm.. any international welders here coming in for vacation? Maybe can broke some good discounted deal...

There have been many valid points made in this thread. For structural application, AWS D1.1 has been the main stay in the US since the early days of steel framed construction with welded connection. The standard has undergone many revisions and it has incorporated many "lessons learned" from failures, both large and small. It is the go to document when welding steel framed buildings. I urge our friend Sedonas to purchase a copy and follow the requirements.

One issue that wasn't mentioned was the base metal being used. If it is ASTM A992 it should be welded using a low hydrogen electrode, i.e., E7018, not E6011. If it is the equivalent to ASTM A36, it can be welded using E6010 if the thickness is 18 mm (3/4 inch) or less. By the way, E7018 must be kept in unopened hermetically sealed cans until they are needed. They must be stored in electrically heated electrode ovens to ensure the moisture levels are kept low enough to meet low hydrogen requirements, i.e., less than 16 ml of diffusible hydrogen per 100 g of weld deposit.

The attached sketch depicts a typical groove detail that is applicable to the beam splice and the subject of this thread.

If skilled welders cannot be found, bolted connections work. Bolted splices are used in bridge construction all over the world.

Best regards - Al

• http://files.engineering.com/getfile.aspx?folder=959b3709-27bf-4351-aa11-07

dont forget even a A36 if its a grade 50, needs a low hydrogen rod.

master ICC inspector, AWS CWI

AWS D1.1 doesn't list ASTM A36 grade 50 as a prequalified base metal. I believe it is the intent that ASTM A992 fulfill that need. As such, all A992 requires low hydrogen electrodes.

Best regards - Al

gtaw: the 1/4" root gap looks a little large for 10mm (3/8") thick material, but I suppose that's because there is a backer bar being used. Otherwise that's the prep I had in mind.

The AWS prep assumes that the weld of the lower flange will be done from the upper (web) side, which is much more likely to give a good result especially with a welder who is not very experienced. The only trick is to ensure that there is full penetration at the web to flange junction in this location, which is why they have ground away material at these locations- to give access for the weld metal to be deposited.

As long as the welding is done in the correct order, and the slag is cleaned between passes, this is the right way to do a splice joint in member like this by welding.

I agree with GTAW: if you can't get proper qualified welders, you can find bolted splice joint designs that can be used instead. They are far more likely to give a good result than a joint which is improperly welded.

I'd suggest to the OP that he consider getting a copy of AWS D1.1.

I told the contractor who is a civil engineer to read this very thread. He still tells me he uses 6011 instead of 6013 precisely because the 6011 can penetrate the 10mm flange and fuse the inside of it even if there is no gap. Can someone explains why this can't work? Because by logic when you increase the temperature of the region to thousands of Fahrenheit.. it should become molten.. so he reasons the 10mm thick flange becomes molten and all parts fuses using the 6011 even if there is no gap.

do the test.
have him weld a piece, cut it through, etch (google this) and see for yourself.

I strongly suggest, as said above, to get the relevant codes (either AWS or european), as most of what is said in this thread is basic knowledge and is imposed by codes.

I agree, there is no better proof than welding a sample to see the results. There is no way the welder is going to penetrate 10 mm of metal using SMAW without some type of groove preparation.

While E6013 does not have the "digging" action of E6010, the 6010 isn't capable of penetrating that thickness without a proper bevel.

However, this isn't the first time where I've see people make assumptions based on nothing more than wishful thinking.

Best regards - Al

He said he used very strong current in the welding machine and combination with 6011 just can penetrate 10mm of flange and turns them into molten and fuse everything in the middle. I need to give him theoretical explanation why this is not possible. We don't have the technology to etch and he lives a bit far for this experiment.. unless I can convince him using scientific reasonings why 10mm can't be penetrated without gap even with maximum current and 6011. Can anyone explain why it can't do in theory? Is it a limit of the welding machine?

Tell him to prove his proposed procedure by taking two pieces of 10 mm plate, butting them tightly together and doing a weld without backer strip (so the root (back side) of the weld can be examined). The specimen then needs to be sent for visual examination by a qualified welding inspector, radiography, root and face bends and tensile tests in accordance with AWS D1.1 or any other structural welding code.

It is extremely likely to fail both the radiograph (due to lack of fusion), and the root bend test. But if it doesn't, you write down the settings of the welding machine, the type of electrode, the base metal used etc. etc. and you now have a qualified procedure and a welder qualified to that procedure. You can qualify new welders to that procedure using a subset of the tests listed above, typically just the visual inspection plus root and face bend tests. Others can give you the list of the rules, or you can read them in the AWS D1.1 standard- again, this is not my area of expertise.

A joint with lack of fusion flaws can be very prone to cracking, because it has a crack initiation site built in- that's why it matters!

There are very good reasons that butt welds in structural steel members (and in pipe) are prepared the way they are. Autogenous welds are possible, but not with a stick welder! The ones I've seen done are done for much thinner and simpler sections, using automated equipment and very different welding methods (tungsten-inert gas (GTAW) as an example). If a stick welding procedure without root gap or bevelling gave adequate and reliable results for butt joints like this, nobody would bother with the grinding and other preparation. There is plenty of motivation to find better, quicker procedures which take less labour, and if they existed they would be used.

Quote (sedonas)

He said he used very strong current in the welding machine and combination with 6011 just can penetrate 10mm of flange and turns them into molten and fuse everything in the middle. I need to give him theoretical explanation why this is not possible. We don't have the technology to etch and he lives a bit far for this experiment.. unless I can convince him using scientific reasonings why 10mm can't be penetrated without gap even with maximum current and 6011. Can anyone explain why it can't do in theory? Is it a limit of the welding machine?

there is no technology in etching, I do this at home with a grinder and acid that is in household products.
you don't need to give him a scientific reason, when this could already be solved by a test that takes 15 minutes - all in. And that will close all discussion.
That will yield more result than this thread, where you are given all kinds of good advice but where you choose not to listen.

and once more - 6011 is not to be used for structural welding. see above.

Got your point, the safer would be to use bolts and cover plates. If the surface of any existing welds in the flange splice is grind with grinder to make the cover plate stick to it flat.. would the procedure makes the welded part weaker? I mean.. if you grind flat any standard beveled butt weld.. would it affect the weld strength? This is to avoid hoping the splice would become stronger by being both cover bolt plated and welded at same time (by ignoring the welding part as contributing any strength).

By the way.. the manufacturer of the wide flange says the material is A36 & SS400 (Special order: A992). What is SS400?? Does it require low hydrogen electrode.

In the US. A36 were replaced with A992. In our country. If it happens and total lack of low hydrogen electrode. Then our structures would even get weaker.

Based on the welds in your photographs, whether you use E6010 or E7018 is a moot point, akin to comparing a 4 cylinder engine to an 8 cylinder engine when there is no gasoline to run either engine.

The shortage of qualified welders is a problem in all countries at this time. Go with bolted connections when there is a question of the availability of qualified welders.

If you still use welding as the option of choice, ensure the welders are qualified by making them pass a test before allowing them to weld on product.

Best regards - Al

Quote:

and once more - 6011 is not to be used for structural welding. see above.

Where is the "above".. I thought Ron said something along the line of "As for the electrode, an E6011 electrode is a penetrating electrode that can be used in all positions. It is a versatile, "all purpose" electrode. It provided deeper penetration; however, it also yield greater porosity and slag inclusions that can lead to nondestructive testing rejection. The welder must know how to use this and other appropriate electodes for the application."

What do you mean (and where is it said) the 6011 is not to be used for structural welding? What other substitute would we use then? Were you referring to low hydrogen 7018? But this is not available locally so all structures use the 6011.

I'm losing confidence in welding.. but there is another problem with cover plate bolted connections. Almost no one use it here to connect splice because they rely on welding.. so I may be the only one in the country who would attempt it. Many structural engineers don't know how to design it. For a w8x1.. usually how big should be the bolt? Since a bolt alone has 36 ksi.. maybe one bolt per side totally 4 bolts is sufficient in the splice? Any cover plates codes about it?

By the way, we don't have any welding code locally so liability is absolutely zero. The welders can't even afford a motorcycle to travel to work, they only commute.. so can't expect any payments for any liability claim.

You lack basic knowledge of welding and bolting and yet you designed a steel structure that is currently under construction?

I am not going to throw stones at anyone's glass house. I've seen some pretty ugly welds in my own back yard. Fortunately, I am in a position where I can insist the bad welds (or member) be removed and welded by someone with the require skills. The contractor may have to pay more to have it done correctly, but at least it does get corrected.

Best regards - Al

The contractor may agree a repair on one of the splices. He plans to use acetylene torch to cut the flange welded region to create a bevel and reweld it. He doesn't have a grinder. He used entirely acetylene torch in all the cuts in the past job. What is your say about acetylene torch to make bevel or gap in the 10mm flange (as prep)? Is it ok?

The oxy-acetylene torch is fine for removing the old weld and preparing the bevel, but the edges have to be ground to bright metal before rewelding the joint. The root opening (the gap between the two members) is going to be rather wide. Backing should be used.

Best regards - Al

Theoretically what's the biggest gap one can join/weld without using backing and using backing? Does it have to do with dynamics of molten metal and filling it and rate of propagation of heat to neighboring molecules? What dictate it in principle?

Also kingnero said above that "6011 is not to be used for structural welding". I'm confused.. what electrode then do you use for structural welding for A36 steel (not A992)? He doesn't give alternative. Why can't the 6011 be used for structural welding? We use it mainly in our country, so I need to know why before starting initiative to ban it.

Generally, if backing isn't used, the root opening and root face equal the diameter of the electrode. Can it be wider? Yes, but it becomes more difficult to achieve complete joint penetration without burn through. Backing makes it easier to achieve CJP without burn through and it requires less skill on the welder's part.

As for the use of non low hydrogen electrode; ASTM A36 contains relatively low carbon and has a low probability for delayed cold cracking if the thickness is limited to 3/4 inch or less. As the base metal thickness increases, as joint restrain increases, and as the percentage of alloying constituents increase (increased carbon equivalency) the greater the potential for delayed cold cracking and an increased need to utilize low hydrogen welding practices.

The cellulose in the flux covering of E6010, E6011, E7010, etc. has an aggressive arc that drives penetration. It is the hydrogen that is produced by the decomposition of the flux covering that gives the EXX10 electrodes deep penetrating characteristics. But there are limits to everything. The ability to penetrate is not without limits.

At best, welding is a compromise. One must weight the advantages against the disadvantages to arrive with a solution that meets the demands of the project. There is no such thing as a perfect weld. All weld, by nature, contain discontinuities of one type or another. When the discontinuity is severe enough that the weld is not acceptable, it becomes a defect. One must consider the application to determine when the discontinuity is harmful to the performance of the weld. Here in the US and in other industrialized countries, they have developed and adopted welding standards that provide guidance to the engineer and the owner as to what practices promote welds that will provide the service and perform as required. Several people have recommended reviewing the requirements of AWS D1.1 Structural Welding Code/Steel. That is good advice. The AWS D1.1 structural welding code is a cook book of how to produce welds that will meet most structural applications. It is based on 100 years of "lessons learned". You can't go wrong by following AWS D1.1.

Best regards - Al

Quote (sedonas)

Also kingnero said above that "6011 is not to be used for structural welding". I'm confused.. what electrode then do you use for structural welding for A36 steel (not A992)? He doesn't give alternative. Why can't the 6011 be used for structural welding?

See the post of gtaw, 30 Oct 15 01:56
See also the other posts, where it is said to get the relevant codes. although maybe not applicable in your country, the principles are valid.
See also the post where I suggested to do the test. What was the outcome?

Quote (sedonas)

He doesn't have a grinder.

This is actually a good thing, so he hasn't got the mean to dress up the welds afterwards.

Quote:

Generally, if backing isn't used, the root opening and root face equal the diameter of the electrode. Can it be wider? Yes, but it becomes more difficult to achieve complete joint penetration without burn through. Backing makes it easier to achieve CJP without burn through and it requires less skill on the welder's part.

Is it a rule that the root opening can't be smaller than the electrode? Won't the filler metal flows into the smaller gap in molten stage? For a given thickness of metal, is there a gap to thickness ratio or percentage of some kind between gap and thickness of the metal to be butt welded? Yes I got the AWS D1.1 documents but couldn't find this rule of thumb dtails. The following is the sample left of the project.



It's cut by acetylene. We plan to use bolted connections and to ensure full moment connection.. we would also weld it and make the cover plate as the backing.

Quote:

This is actually a good thing, so he hasn't got the mean to dress up the welds afterwards.

Why is it a good thing? They didn't dress up the welds afterwards but just paint them with epoxy primer.

About the test. Well.. the old contractor won't even talk to me.. much less spend time on any test because we paid him full already. In our place, welders and contractors have zero liability.. we don't even know their full names. So we need to use hybrid bolted and welded connection and oversee every step of the critical repair.

Mixing bolts and welds in the same connection isn't a good idea. The bolts will slip under load, thus the load is transferred into the welds. If each, the bolts and the welds, are not capable of transmitting the entire load, failure can occur. Once the bolts slip, the load is transferred to the weld. If the weld isn't capable of transferring the entire load, they will fail. Once the welds fail, the load is transferred back into the bolts, which if they cannot sustain the entire load, well, we don't want the worst to happen do we? Even slip critical bolts are expected to slip slightly when the faying surfaces are painted unless the paint system has been tested and demonstrates the ability to transfer the loads without slippage.

CJP groove welds without backing are not prequalified per AWS D1.1. Thus, the figures in clause 3 depicting the prequalified groove details show either welds that are backed, welded from both sides with a back gouge operation, or partial joint penetration. Any CJP groove weld made without backing or welded from both sides with a back gouge operation must be qualified by testing to demonstrate the contractor and the welders have the skills necessary to do it successfully.

The dimensions I offered are rules of thumb developed over forty years of welding experience. Call it tribal culture if you will.

Best regards - Al

Quote:

Mixing bolts and welds in the same connection isn't a good idea. The bolts will slip under load, thus the load is transferred into the welds. If each, the bolts and the welds, are not capable of transmitting the entire load, failure can occur. Once the bolts slip, the load is transferred to the weld. If the weld isn't capable of transferring the entire load, they will fail. Once the welds fail, the load is transferred back into the bolts, which if they cannot sustain the entire load, well, we don't want the worst to happen do we? Even slip critical bolts are expected to slip slightly when the faying surfaces are painted unless the paint system has been tested and demonstrates the ability to transfer the loads without slippage.

Is there by chance the cover plate bolts need to be tightened using torques wrench? In our country. Our contractors don't own any torques wrench.. they just use manual wrench to tighten bolts in base plates, and weld the top of the bolt and nut so they won't come apart. How about the bolts and nuts in the cover plates.. it's okay to weld them too so they would be fixed in place?

According to other structural engineers. It's so rare for contractor to create splice in wide flange by using bolts and nuts.. they said it's so expensive.. it's easier to just weld it they said.

So in the event even bolted options would be out of reach.. then may have to invite international welder to repair the moment critical splice.

Unless I completely missed it when I went back and re-read the threads, gtaw did not say that E6011 should not be used for structural welding. He did say, and correctly so, that E6011 should not be used for welding when a low hydrogen electrode such as E7018 should be used for A992 steel.

While E6011 has many good attributes and properties, I believe the point gtaw was making was that the electrode must be matched to both the base metal and the application. He knows his stuff! Go back and read all of his posts...then follow his recommendations.

Quote:

Mixing bolts and welds in the same connection isn't a good idea. The bolts will slip under load, thus the load is transferred into the welds. If each, the bolts and the welds, are not capable of transmitting the entire load, failure can occur. Once the bolts slip, the load is transferred to the weld. If the weld isn't capable of transferring the entire load, they will fail. Once the welds fail, the load is transferred back into the bolts, which if they cannot sustain the entire load, well, we don't want the worst to happen do we? Even slip critical bolts are expected to slip slightly when the faying surfaces are painted unless the paint system has been tested and demonstrates the ability to transfer the loads without slippage.

I'll buy a torque wrench if contractor doesn't have it. I prefer the splice bolted.. as you said.. bridge has bolted splice. In your experience.. what happens to the weld when you grind the surface flat.. because if I'll put the cover plates and bolts.. I'll have to grind the bottom of flange flat.. would this procedure weaken any weld even in normal welds?

Also in cover plates and bolts.. should there be gap in the splice? I'm asking because if we would acetylene away the old weld to put cover plates.. it would be messy.. so instead we would put the plates without removing the old welds.. the plates designed would be peer reviewed by local team to ensure it can mobilize the full moment capacity of the beam. I'm more confident with bolted connection because of lack of any skilled welders.

So many thanks for the assistance.

The welds in your photographs are of questionable utility regardless. Grinding them flush with the surface of the flanges will not degrade the function of the welds. If anything, there may be some unexpected surprises waiting for you once the welds are ground flush.

High strength bolts are tightened to provide the clamping force needed to ensure the connections cannot slip. If the bolts are not fully tightened and if they do slip, they will go into bearing, i.e., the bolt will fetch up against the side of the drilled hole. This is an acceptable condition if there is no cyclic loading that would cause the bolts to move or slam back and forth in the bolt holes. It is important that the bolt holes be drilled rather than torch cut or drilled oversized. To function properly, all the bolts have to be in bearing, i.e., the shank of the bolt against the side of the drilled hole. Initially, one bolt will bear against the side of the drilled hole. The base metal will go into yielding as it is over loaded and the next bolt will go into bearing and so forth until all the bolts are bearing against the side of their respective bolt hole.

High strength bolts installed in unpainted connections and fully tighten to a prescribed preload depends on the clamping force and the resulting friction to transfer the load from one member to the next. That's why we used to call them friction connections. Now they call them slip critical connections meaning the clamping force should be sufficient to keep the bolts from slipping into bearing. In the US, we specify slip critical connections if there are load reversals so the bolts will not slam back and forth as the load changes. It is important to ensure the bolts are installed and tightened properly if the connections are specified as slip critical. I usually use either A325 or A490 bolts and the turn of nut method of tightening these connections. Both ASTM A325 and ASTM A490 bolts are high strength quenched and tempered steel. DO NOT WELD THESE BOLT TYPES.

Bearing connections are typically used in structures that are not subject to cyclic loads and where there is no chance there will be load reversals. The installation and tightening is not as critical as long as the bolt holes are not over sized. ASTM A307 bolts are fine for bearing connections, but their "low strength" will require more bolts when compared to A325 or A490 bolts of the same diameter.

The AISC Steel Construction Manual is a good reference for bolted connections.

This has been an interesting thread. I am glad you took the time to bring it to our attention. We sometimes forget the operating conditions of localities other than our own.

Best regards - Al

Thanks for the tips.. what would happen if you weld the A325 bolts? This is what the contractor did after installing elsewhere. they weld the bolt to the nut and baseplate to ensure they are locked. Now I'm losing confidence in cover plates bolted connections because we don't have the machine wrench that can do the work. Hand works may not be enough.

This is the welding machine commonly used in our country (it costs about $150). Is it like it in your place or is there something missing in the following?



Now I must look for repair welder of expert nature. I will first discuss on a theoretical level to see if he pass. The old welders told me they only focus on the web in I-beam because they consider the flanges as not taking any important functions.. they don't understand about compression and tension zones.. although I may print some to show them one final time if they can comprehend it. Then I'll ask the new welder about backing bars and bevel and how big it is.. to test if he knows gtaw world.. if he passes but not using right equipment.. may have to let him bring the equipment from abroad too.

How long usually to fix per splice.. because there are 4 splices.. I wonder if he can do it in 2 hours or need 2 days.. because need to estimate my budget for him, the worse if need to get international welder because have to accommodate him to hotel etc. In neighboring hong kong, china, Singapore.. do you think there is even one competent welder or do I need to hire one as far as the US or even Russia. We don't have any welding code in our country. I wonder if Hong Kong, Singpoare have welding codes and how they differ to that of US AWS D1.1?

Gtaw.. in addition to the above.. may I please know the following.. these will be the last questions.. thanks a zillion to you and others

1. How many times can one reweld and reweld the same portion. For example. If the new welder didn't make it right.. and we grind/acetylene the bad welded flange again and then the third welder failed again, and we regrind.. reweld.. is there a limit to the repair cycle?

2. When grinding.. can one grind just a portion of the welded filler and assume the filler (if it is of good weld) is as good as the original metal or do you have to remove all the welded filler part when doing reweld? After 5 reweld jobs by different welders team.. I wonder if the gap can become bigger or it would just stay constant as the new team simply remove the welded filler part..

Many thanks!

Based on the photographs you provided, the existing weld should be removed entirely and replaced. The welder should not be expected to be an engineer, metallurgist, and welder. The welder may have the skills needed to deposit acceptable weld, but he will likely need direction as to what needs to be done to correct the existing connection.

The root opening will become larger with each successive repair if the entire weld is excavated as it should be. The welder can deposit weld to build up the groove face to reduce the size of the root opening. The welding should initiate on one member to build up the groove face first. Backing should be used to provide the welder with the best opportunity to make an acceptable weld. I would limit the maximum build up the thickness of the flange, 10 mm in your case.

However, looking at the welds in your photographs, it would be easier to remove the affected section and replace it with new a new section of WF.

Done properly, the weld should be as strong as the carbon steel that comprises the WF beam. The attached sketch depicts what I would consider to be a reasonable approach to correct the problems depicted in your photograph. In the long run, it will save time. It can be modified to be bolted if it is easier than finding a competent welder.

As for the welding machine in your photograph; it is fine if the welder uses E6011 because it appears the output is AC only. E6010 electrode is intended to be used with DCEP (direct current, electrode positive). If the welders attempted to use E6010 with AC output, it would explain some of the problems they experienced.

Best regards - Al

• http://files.engineering.com/getfile.aspx?folder=ddf5582b-3312-4fde-8ab6-2d

Sedonas, in answer to your earlier question on what would happen to the bolts if welded which hasn't been responded to:-

I believe two things happen (in simple terms) when welding quenched and tempered steel
1 - Risk of hydrogen embrittlement - hydrogen atoms enter the metal, with the risk that the steel in the bolts become brittle (as opposed to being ductile)
2 - The heating and slow cooling 'undoes' the hardening that happens during the quenching process - lowering the strength of the affected steel.

As gtaw noted, never ever weld high strength bolts, or never reuse previously tensioned bolts.

If there are bolts that have been welded they should be replaced asap.

By the way. If 10mm thick flange splice were not beveled Vee shaped at both sides or no backer used and there is a slight gap (not entirely touching) say a 3mm gap (below size of electrode). Wont the weld filler be able to pass thru the 4mm gap? The contractor is saying there is a slight gap where the 6011 molten filler were able to move thru it. What can you say about this minimal gap dynamics?

I think we've pretty well covered that a couple of days ago.

Best regards - Al

Quote:

I think we've pretty well covered that a couple of days ago.

When you mentioned this a couple of days ago "Generally, if backing isn't used, the root opening and root face equal the diameter of the electrode. Can it be wider? Yes, but it becomes more difficult to achieve complete joint penetration without burn through. Backing makes it easier to achieve CJP without burn through and it requires less skill on the welder's part."

I'm talking about not wider, but narrower than the diameter of the electrode. Perhaps your experience says that root opening and root face equal the diameter of the electrode in order for the arc produce by the welding rod to get into the gap.. but if it's narrower, maybe some arc can also get inside the gap.. perhaps enough to put the middle in molten stage?

In welding, the welding rod is what produce the molten arc, if the electrode is bigger, the arc get bigger and it is dependent on the size of the electrode? or is it not dependent on the size? For example.. if you don't use filler electrode but just use wires in the holder.. would it also have arc, and how big would this arc be? This is to understand the relationship between the arc and the electrode size in scientific details.. not just engineering. It's not in the AWS D1.1 which is an engineering manual. Thank you!

What did the practical test say when presenting this scenario?

OK, I see what you are driving toward. If the root opening is insufficient, the weld may not penetrate to the rot. The weld will increase the welding current to achieve more penetration, but at the expense of the probability of burn through. The weld and the arc are harder to control.

Best regards - Al

In splicing the wide flange.. the welder uses acetylene to cut it. Since its not staight cut and the edges are rough and uneven and they dont own any grinder. Dats how some 2mm gaps were produced with some in contact some not.. you said 2 messages prior about replacing whole sections of it. Wont it be harder since now one has to make 2 splices?. and they would exceed the L/4 locations we were told to splice. So better options would be opening the gap right in the weled portions and either use backing or Vee shaped bevel on both sides.

By the way when you mentioned more possibility of burn through with larger gap without backing. Were you referring to the gap not being able to fill up? Because burn through is supposed to happen when its thin sheet and you burn through it.. does this term also refer to unfilled sections? Is the term burn through accurate here..

Burn through is whenever the welder melts through the base metal and leaves an unfilled hole.

My suggestion that it would be easier to remove the entire compromised section of beam is based on what I saw in your photographs, specifically October 28 at 1:58. Attempting to fixing what is depicted by that photograph is nothing short of opening a nasty can of worms. It would take a magician to fix that, not just a welder.

The cost of a grinder to properly prepare the joint and to allow the welder to remove questionable weld is a lot less expensive that trying to repair the connection we've been discussing for the last several days. There are a few basic tools needed to do any job properly. A mason needs a trowel, a carpenter needs a hammer, and a welder needs a grinder. The mason can substitute a stick for the trowel, but the job is going to suffer. The carpenter can substitute a rock for the hammer and the welder can substitute a hand file for the grinder. At some point one must think about the cost benefit of having the proper tools to do the job.

Best regards - Al

Thanks for all the basic. I've been reading AWS D1.1 too.

Gtaw. When you joined purlins to purlins of 1.6 to 1.8mm thickness. Do you use 6011 or 6013 electrode? Won't 6011 burn thru it.. and if you use 6013.. won't it be not enough to join the metals? We only have 6011 and 6013 available locally. Thank you.

For joining Purlins/girts of such thin cold-rolled sheets bolted lap joint is generally preferred.

If welding is the choice then to gor MIG welding rather.

Best Regards_ VH

We don't have this technology called MIG (Metal Inert Gas) welding and lack of availability of bolts designer.

We only have SMAW (Shield Metal Arc Welding) technology and 6011/6013 electrodes. There must be a way to weld 2 pieces of 1.6 to 1.8mm purlins. Do you fillet weld this? Won't the welding holds if done properly? A structural engineer said the 6011 is too powerful for it.. he only suggests 6013. We will have new group of welders for this job. The old welders can't be found anymore. They ran away already. So before we pay the new welders. We want to make sure they welded the purlins right. Thank you.

For cold-Rolled purlins members; standard bolted Lap details may available with purlin manufacturer catalogue.

Welding of such small thickness sheet with stick is rather difficult than Wild flange sections welding and may reqd more skill-sets!

Best Regards_ VH

Our purlins came from china.. we never use bolt laps.. no one here uses it so it would even be more immensely difficult.

We really only have SMAW and 6013. What skill sets must be observed. They already have the welding machines and electrodes and purlins delivered in site. They will start welding tomorrow. One local structural engineer said it must be stitch weld.. that thin sections will just tear if bolts are used.. to be sure.. we will weld every surface (stitch weld).. 6011 is too powerful and should be avoided? The 6013 is the only one available. It should be enough to melt the metal and connect them on atomic level. Please share techniques so I can see to it the new welder follows it tomorrow and for next 2 days. Thanks.

Quote:

For cold-Rolled purlins members; standard bolted Lap details may available with purlin manufacturer catalogue.

Welding of such small thickness sheet with stick is rather difficult than Wild flange sections welding and may reqd more skill-sets!

Best Regards_ VH

The senior structural engineer advised against bolted purlins because he said they can tear especially if there is movement in the frame.. therefore welded purlins are advised.. anyway can you show pictures of any bolted connected purlins? Maybe they are not for seismic.

The welded parts are more ductile and can move. He advised using stitch weld with the electrode 6013 in SMAW..

But since he is not welding expert.. never personally weld.. I'd like to hear from gtaw or others who have welded hot rolled thin sheet 1.6mm to 1.7mm the best way to stitch weld or what to watch out.. thanks in advance.

I did not read every post, but those are the worst welds I have EVER seen. Everything about it is terrible.

The senior structural engineer said we never use bolts on purlins. That all the hundreds of billboards in the streets don't use bolts but welded. Reviewing the old welding jobs. I realized all the purlins were spliced welded like the following:



Searching in the net for bolted pulins. I found this:



But these are Z purlins and they are coated. Our purlins were bare steel without coating.

What is the best way to ensure the 1.8mm spliced purlins will have welds that fully combined them in the atomic level (or complete weld)? Should 6011 or 6013 be used?

In our country. Designers don't give any details about weldings because they said their job is not welding (they don't know how). So it is the job of the welders to make it right (or wrong). In the structural plans. There were no mentioning of what kind of welding.

Our designers are one of the biggest in the country:

http://www.rbsanchez.net/

But they are not familiar about welding.. saying it's up to contractor to do it right. But my old contractor has already ran away. They just hired welding subcontractor who don't even own any welding machines because they can't afford it. In our country. 99.5% of welders don't own any welding machine.

This is the reason I can't do any edging test kingnero suggested.

Just tell me. Will 6011 or 6013 achieve full fusion of the 1.8mm thick purlins to be spliced? I'm reading the AWS D1.1 but can't find it. Please give a tip or two more... esp. gtaw.. many thanks!

What is the material specification of the structural members?

If they are ASTM A36 (or the equivalent), they can be welded with E60XX electrodes, but the thicker the material, the more preheat is required to mitigate the possibility of hydrogen cracking. AWS D1.1 allows ASTM A36 to be welded with E60XX electrode (E6010, E6011, E6012, E6013, etc.) up to a thickness of 3/4 inch (about 18 mm). One can weld thicker sections, but the possibility of hydrogen cracking increases slightly and higher preheat should be used.

E60XX isn't recommended on ASTM A992 wide flange members because of the higher strength, i.e., 65 ksi) and higher carbon equivalency. That isn't to say it can't be done, there is simply increased risk.

Best regards - Al

Material Specification is "A36 and SS400". From our supplier..

http://www.reganindustrial.com/home.php?pg=section...

What do you think about SS400?

See http://www.meadinfo.org/2010/09/jis-g-3101-ss400-s...

I dont know if it means combination of A36 and SS400 alloy or either only?

For you stitch weld is same as fillet weld isnt it

So 1.8mm thickness vs 10mm thickness weld is controlled by the current. I talked with the new welder now he said 6011 can be used on 1.8mm thick purlins by controlling the current. He is not metallurgist but jus ordinary welder who earns $15 working 10 hrs so need opinion and experience of others abt 6011 on thin sections. Tnx

It would appear they are equivalent.

An intermittent fillet weld is called a stich weld by those individuals that are unfamiliar to standard AWS terminology. A stitch weld is "slang" or non standard term for an intermittent fillet weld.

E6010 or E6011 would provide a more aggressive, penetrating arc than E6013, but all three have the same minimum tensile strength if the weld is properly deposited. With the aggressive penetrating arc there is the potential for increased levels of diffusible hydrogen. However, on 18 mm thick low carbon steel, it should not be an issue if the minimum preheat (say 40 degrees C) is maintained.

Best regards - Al

Gtaw i was NOT referring to 18mm. But thin 1.8mm section

So 1.8mm thickness vs 10mm thickness weld is controlled by the current. I talked with the new welder now he said 6011 can be used on 1.8mm thick purlins by controlling the current. He is not metallurgist but jus ordinary welder who earns $15 working 10 hrs so need opinion and experience of others abt 6011 on thin sections. Tnx

Post Edited

OK, I missed the fact that we changed gears and now we are solving a different problem.

Yes, the welder can weld the thinner purlin with E6010, but for the thin material, the E6013 would be a better choice because it is better suited for thin material.

Best regards - Al

gtaw.. I wonder if you agree with this web info about the difference between weld fusion and weld penetration.

http://www.lincolnelectric.com/en-us/support/proce...

"Theoretically (but not realistically), you could even have complete fusion to just the depth of a few molecules and still have welded the pieces together."

So the trick in thin metal welding is enough weld fusion to molecularly combine the purlin to purlin.

But why did some believe you need Metal Inert Gas (MIG) welding for thin section.. like they believe Shielded Metal Arc Welding is not even possible or so hard. For you. Do you use MIG or SMAW in thin section (1.8mm purlins) and why?

Someone without the skill to butt weld together 10mm thick sections of carbon steel with a stick (SMAW) welder, will not be successful butt welding a 1.8 mm thick member. They will melt through and make a big mess. If you can lap the two pieces over one another and deposit a fillet on both sides of the joint, they might have a hope.

I am not a welder whatsoever, but even I can successfully weld material less than 1 mm thick using "hard wire" metal-inert gas (MIG). I can even manage reasonably well using flux-core MIG, though the welds look terrible and need a lot of clean-up.

In our place. We don't use MIG because it is heavier and it can explode.. note our welders don't wear any protective gear.. they only use clothes to cover their face and broken shades because they can't afford any protective gear (imagine those ISIS in Syria figure doing welding).. remember our welders never own any welding machine because they can't afford it so they use their contractor machines. Hence the difficuly of any edging test because of 2 unwilling participants.

Anyway. Whatever is the repair of the wide flange splice.. we need to reinforce it... so we will support the entire wide flange with vertical C-section beam every 2 feet (to carry 42 lbs of weight.. it's w8x21 meaning 21 lbs per foot). The vertical Cee section (called purlin if horizontally) is about 1.7mm thick and we will attached it to the top of the wide flange every 2 feet. The wide flange is originally to brace the cladding wall below but we redesigned it to carry the wide flange above which will have no load anymore because of the weak splice (it's supposed to carry another wall).

So what's the best technique you guys experience to weld thin section to thick section? Imagine 1.7mm vertical Cee section braced to wide flange top flange using 4.5mm x 2 inches angle bar brace.

Earlier we talked about welding thick section to thick section, then thin section to thin section.. now thin section to thick section. The AWS D1.1 is a cookbook but we need seasoned welders to share their unique experiences using Shielded Metal Arc Welding (the only one we have). So should 6011 or 6013 be used? Gtaw? Thanks.

E6013 using AC is intended for "thin" base metal. It does not penetrate the base metal to the same extent as E6010 or E6011.

I believe E6013 would work fine is the welder had time to practice and develop the technique. I would suggest using 3/32 inch diameter (5 mm) electrode for the thickness your working with.

Best regards - Al

Gtaw. We changed gears 2 messages ago and solving a third problem.. that is welding thin to thick metal or 1.7mm purlins (Cee section) to 10mm wide flange flange. You are saying that whenever there is thin section mixed with thicked section. one must use 6013 and treat the thick section as thin one by aiming for just enough weld to make the two atoms mixed or just enough weld fusion (edit: i meant weld penetration) equal to the thin metal thickness or 1.7mm on the 10mm thick material?

Here's pic of my new welder welding the 1.7mm vertical Cee section (purlins) to a 4.5mm angular 3x3".



I gave him the 6013 3/32 electrode.. but he told me a while ago it takes too long to weld.. he wants bigger one.. should I give him larger version of 6013 (what is it) or should I give him a 6011?

Remember he is just a welder.. been welding for dozens of years.. this is what the welders in our country looks like. He is not metallurgist so let's analyze the interaction of the welds at the molecular level.

In other words.. a 6011 with low current and a 6013 with high current would be equivalent?

And a bigger 1/8 6013 would be stronger than a smaller 3/32 6013?

Because when welding thinner 1.7mm Cee section with 4.5mm angle bar.. it seems to take long. Since we are in charge of budget.. we can dictate what we want.. so if he can make the currents lower as he said.. can I give him the 6011? Or is 6011 with low currents functions differently than 6013 with high current? He is asking now. I need to decide. Please tell me now. I can't read AWS D1.1 in one reading now since it would take days.

In a nutshell. What ingredients are 6011 and 6013 made of that makes them differs? does one conduct more and lower resistance hence stronger?

Thanks.

Both electrode meet the minimum requirement of producing a weld with a tensile strength of at least 60 ksi.

The flux covering on E6010 and E6011 have cellulose based coverings that decompose in the presence of the high temperature arc and liberate plenty of hydrogen. The hydrogen produces a deep penetrating aggressive arc.

The E6013 is a rutile base flux covering. It does not liberate as much hydrogen as the E6010 or E6011, but still enough hydrogen that it cannot be classified as low hydrogen.

The depth of fusion only has to be sufficient to ensure the weld is completely fused to the base metal.

Your welder should not be welding with "sun glasses". The lens is not dark enough and his face is exposed to the ultraviolet radiation. The poor bugger probably cannot see the weld pool after a few seconds of arc time, burning the skin (sun burn) and causing permanent damage to both skin and eyesight over time. It is little wonder the weld quality suffers.

Any tradesman needs to have the proper tools to do the job properly, quickly, and safely. This fellow has a loaded gun, but the barrel is pointed at his own head!

Best regards - Al

Thanks for the tips about ultraviolet. Ill get shades for myself because i observe the welding too from afar under sun.

About welder. 99% of welders in our country wears sfuff like it. Remember their $15 daily wage is to support their family including schools. It explains why most dont have extra money after each weekend. Much less to buy any protective gears.

Thanks so much gtaw and others. I wonder what is the cheapest welding tester unit like ultrasonic or eddy current etc one can afford (like you guys) so i can personally test the weld fusion and penetration integrity.

The very cheapest unit is your own eyes and a little research about what to look for. No weld you'd posted a picture of here so far would pass visual examination.

+1 from GTAW regarding eye protection. Please stop saying $15/daily wage. It should be the contractors responsibility that everyone on the jobsite is working safely. Eye protection is essential to welding, and sun glasses are not sufficient. You should also not be watching welds be made without eye protection, no matter how badly you want to look. You WILL suffer flash burn, which is like sun burning your eyes. The welder's eyesight is not worth the money (or any money for that matter) you all pay. This whole thread makes me not want to visit your country. Also, "engineering" being conducted by obviously unqualified people, and using this site as an RFI for an on-going project is not ethical.

Oh. When the welder did full weld. They covered their faces with their a shirt wrapped around the face. This is the common sight of welders you will see in every building being constructed.. very rare will you see any welding protective gear.. The following were the old welders who did the wide flange splice using 6011:





In a welding arc, isn't that the spectrum distribution is like blackbody radiation.. so the ultraviolet component is just very small.. or nonexistent.. what's the value of ultraviolet in an arc?

Welding arcs are RICH in UV radiation! Caucasians like me get sunburns on their arms from welding if we don't cover up. And when you get a sunburn on your eyes, it HURTS- it's happened to me.

Light reflected from an arc is much less rich in in UV.

Plastic glasses may or may not block the damaging UV. The same goes with glass sunglasses. I've run spectra of these personally and found some that are amazing at blocking visible light but let in the entire 300-380 nm UV band. But that shirt wrapped around their head is no special protection against UV. Every hole in the weave you're looking through is letting unattenuated UV light right into their eyes.

Look- somebody is building a structure there. Whoever that is, has some money. Money is coming from somewhere to rent welders and buy consumables, as well as to pay you whatever you're being paid. Take some of that money and buy a few of the old-fashioned drop-down welding masks- they cost virtually nothing. It will not only reduce the number of people with cataracts later in life who will be cursing you because they can't afford corneal transplants and are blind- it will also GREATLY improve the ability of the welders to see what the hell they're doing while they're welding! Welding blind is impossible, and that's what these guys are trying to do!

I paid the contractor (he hired his welders) over $10,000 for the job. This is what they gave me. I am learning what is the proper welding technique and principles so I can know if what they are doing are normal in the industry and how spread these style is.

Well. I'll check the high rise and other buildings in the metropolis to see what welding techniques and style they use.. and then I'll know whether my contractor and his welders are the normal.

Many thanks for the assistance especially gtaw and others. I'll read AWS D1.1 while watching the contractors and their welders do it.

OK - I assumed you were an engineer hired by the owner as a construction manager!

Mister Owner, I suggest a) you hire some competent and trustworthy engineering and construction management advice if you don't want your building to fall down and b) since the welders you're hiring are poor (in both economics and skills terms), it is in your interest to equip them properly so they do a good job for you.

Paying cash for any workers is never going to work. You need some fundamental changes in your country. Owners in North America never have to go to this effort. In fact, if they did many people would be fired and they would be in court fighting for years. Nonetheless, this has been a very interesting discussion and exposure to the methods in another country. I am very pleased not to have to deal with such problems.

This is the hierarchy of construction here. Owner deals with contractors. The contractors workers boss is their contractor. I had several times at odds with the workers because they won't follow my direction (they listen to their boss only). Construction hire engineers to check the project. But the engineers is as bad as them. The engineers salaries are even lower at only $10 a day (our average daily wage is $10) and these engineers don't even know the meaning of moments so consistently I'm always at odds at them for not following development length for example.

Yes. I should have hired competent construction manager. The contractor got my $10,000 already before writing this thread and realizing their bad job. They won't even return to fix any saying the job is finished. The contractor spent about $7,000 on materials. He earns about $2000. Paid his welder foreman about $1000. The foreman distribute the $1000 to himself, his welders and workers.. that's how each worker ended up with $15 a day.

About equipping the welders directly. They won't listen and not even aware what is ultraviolet. The worker I talked to thought it was some kind of color.

I have a new problem now. They will be sawing many Hardieflex cement boards using ordinary grinder starting tomorrow for a week. I told them the dusts are dangerous to the lungs and need some kind of vacuum. They told me they have been doing it for dozens of years and they can manage and thought I was crazy for suggesting vacuum which the contractor never owned.. So now I cant even go to the job site with all dusts flying around me. If I don't go there. I won't see their work. So I'm thinking of spraying the floor each morning with water to make the cement board dusts go down the drain. I also have nose masks but I don't have oxygen mask so still very nervous about this all.

Maybe you guys think Hardiflex dusts are harmless to the lungs. Please convince me so my nervousness would be gone. Thank you!

James Hardy has a best practices document for safety when using silica based fibre cement board:

http://arc-architectural.com.au/wp-content/uploads...

They also have installation instructions for each specific product, along with safety information, on their webpage.

Is it genuine James Hardie or some knock off from China? If the later, you are on your own. If James Hardie they have guidelines and best practices at http://www.jameshardie.com.au/uploads/file/2014081.... I have cut it with simple mask outdoors. Long sleeves are better because of the fineness of the dust. Unless your saw is equipped with an appropriate deflector to collect the dust in a vacuum I am not sure how effective it will be. There are many saws with such deflectors, but I doubt they are in the budget based on what you have described thus far. A vacuum for this work is also quite expensive if you want it to last. The dust is incredibly hard on vacuums. We take these things fairly seriously because of the quantity of lawyers and the risk one can assume. Most owners would ask about their risk exposure.

We hold back money to avoid some of the welder problems you are dealing with. Most subtrades must wait at 45d after they are finished for the last 10% of their funds. They also must provide evidence they paid their sub trades. That protects an owner from a lien. I am having a hard time believing you cannot find qualified welders in your country. We do not hear of enough collapses to support such a conclusion. Did you hire on the basis of cost alone? If so, you must shoulder some of the blame. There is a lot of truth to the one poster that said, "pay peanuts, get nuts." Does this society http://www.indonesianweldingassociation.org or https://www.facebook.com/Indonesia-Welding-Enginee... list members one can hire that are something more than a guy that learned to weld by practice alone?

Hey gtaw....go back and copy and paste all your replies in this thread into a Word document and you'll have the first couple of chapters of a good book! Nice explanations...all.

Yes. I requested James Hardie cement boards but they dont follow any precautions so i think ill just avoid the site for a week and hope it rains next week to remove all the dusts.

Im sorry. My location is really the Philippines. I mentioned Indonesia because want to be anonymous and just interested in the principles but since the industry is involved then have to say its the Philippines.

Many architects avoid steel structure precisely because of poor welding practice. So most of our buildings are purely reinforced concrete.

I found out we have the Philippines Welding Society.. they are associated with Tesla welding schools. My old welders were all graduates of the schools. Only mostly poor workers enrolled in it to find any jobs. If you know one good welder in the Philippines US standard gtaw grade. Pls let me know. I still cant find a good repair team to repair the splice or any confidence. Tnx

Best I could suggest is to post a comment on one of the schools like this. https://www.facebook.com/HEATS.Inc/ I have never met a welder that did not take great pride in their ability to put down a nice bead.

Your fabrication process is very different from ours. Almost 80 - 90% of our steel work is welded in huge shops that are highly automated. Every piece of steel is detailed and approved by the engineer (qualified) prior to any fabrication. Each piece is clearly marked and they provide a erection drawings. We use bolted connections as much as we can because the site crews are too expensive. The crews you have seem only qualified to turn a spud wrench. If you do this again, I would find a fabricator from China or somewhere else that details the structure properly before shipping to site. A vast amount of structural steel from North America is detailed in China or India now, so finding qualified persons for that is easy in those countries. The process you have now seems to blur who is responsible for what.

I agree with Ron, gtaw has been very helpful to many reading this thread.

Here's the worker cutting Hardieflex board a while ago and directly inhaling the dusts (he only covers his head from the sun but his nose and mouth open):



I told him inhaling the hardieflex dusts from cutting is dangerous.. but he just laughed saying he has done it for several years. He is the same welder who wear shades welding. Note our welders are mostly common workers so they also do other jobs like cutting and installing hardieflex, etc..

The shot was taken using a CCTV camera at the site. I'm afraid to visit it directly now.

I'd like to know how long can silica stay airborned before they fall to ground by gravity. I can't find this in any web sites. I need to know so I can estimate how long before they settle by gravity and the floor can be decontaminated by spraying water. And does wet cleaning means simply using water hose to wet the ground to let the dusts flow the drain? Is this effective? Do the dusts stay at the walls too or surface of object? Because we can't wet the entire floor due to bare steel still to be primered or cut.

This is my immediate priority now in addition to bad welding because I can't visit the place unless I know effective ways to remove the dusts before I step inside. Thank you.

Why are you not kicking him off the site? He who signs the cheques makes the rules. If you want him to wear a mask, and you provide it, he should wear it and be quiet. This is very disrespectful to an owner.

Because we owners deal with contractors.. we don't interact directly with workers... they won't listen to us, they have their ways. And the contractors don't believe inhaling hardiflex dusts is hazardous himself.. because he inhales them too..

I have to let the caretaker wet the entire floor early at morning.. but would this remove all the silica?

But note that even when chipping concrete.. there are silica released.. and even mixing cement would release silica.. so the hazard is everywhere.. maybe they are so used to it that it become desensitized.

This is the only respirator (half face with the paint cartridge) available at a large depot. I got it to take a peek at the fillet welding (2 pictures shown below). I researched for over 2 hours about the difference between particulate respirator and vapor protection respirator.. logically.. you can use vapor respirator to avoid Hardiflex dusts but it seems there is a reason it can't and I couldn't find it at any web site. Wikipedia says:



"For maximum efficiency of particle removal and to decrease resistance to airflow through the filter, particulate filters are designed to keep the velocity of air passing through the filter medium as low as possible. This is achieved by manipulating the slope and shape of the filter to provide larger surface area."

I can't find the scientific reason why vapor respirator can't be used for particulate.. any idea why?

below are the welds that connect a 1.7mm C section with a 4mm angle bar done by the new welder (with over 10 yrs experience trained by the Philippines Welders Society affiliates). how do you tell if there is weld penetration (a few regions enough to take the load isn't it).. it may look ugly but if there is weld fusion.. it is enough to join the filler metal and base metals molecularly... (edit: done using 6013 stick with using SMAW (Shielded Metal Arc Welding which is the only one available locally)

I think you already know what our reaction to those welds are going to be. Without a grinder to grind off slag you're going to have impurities in the weld and get a weld that looks like that. On the bottom picture, the left side of the weld almost looks like a decent weld...Almost

They used hammer and hit the weld to remove the surface black slag. So I should check each connection and make sure all slags are removed to see what's at bottom.. but for such thin sections.. there should be fusion beneath the slags.. isn't it.. by impurities you mean the slag is covering the welds or part of the mixture?

Btw.. he didn't remove the epoxy primer because they just painted it last week and would take too long to grind each (and the contractor refused such time consuming task).. and let's say the epoxy reduce the strength.. it's full weld so there should be full load bearing in between members for such small section (again 1.7mm C section on 4mm angle bar).. isn't it.

Hardieboard is cement reinforced with cellulose fibres. The dust is cement dust, and the fibres themselves are nonhazardous. Yes there's a theoretical risk of harm from the dust- similar to what you'd get dry-cutting concrete. It's far better (and faster) to cut the stuff with a shear than with an angle grinder. But frankly I'm far more worried about your welders' eyes than I am about the dust exposure.

Buy the guys some old-school drop-down welding masks. The quality of their work will increase by leaps and bounds in a very short period of time- it's amazing what you can do when you can SEE WHAT YOU"RE DOING!

You mean just wearing shades they need to close their eyes to weld.. hmm.. i'll ask them tomorrow about this and maybe give them welding goggles they can't afford.. here's what they are building:



Originally the wide flange above it will support a concrete wall above and hardieflex below.. but because of the bad splice.. we would no longer add a wall.. instead we will use the C sections and hardieflex below to support the wide flange...

Hardiflex says one middle support of it's 1.2 meter width hardieflex enough. Our designer makes it two. And instead of the original 1.4mm thick C section. We made it 1.7mm thick C section distance every 400 mm apart.. this will make them carry the w8x21 almost 21 lbs every 400mm vertical strut C section.. this will transfer the moments of the wide flange to the parapet wall below it (one meter height from slabs). This transform the frame into light gauge structure building... hopefully the safety margin and welds would make them rigid.

No pair of sunglasses is as dark as a proper welding mask. The dark glass of a welding mask is not only effective at removing UV, it's also dark enough so that you can actually watch the puddle of molten metal as you're depositing it so that you can control where you're putting it, and how much the parent metal is melting etc. If you look at the arc with glasses that aren't dark enough, your vision will rapidly be impaired by flash-blindness (phosphenes- the coloured blobs of light that persist in your vision for a while after looking at a bright thing).

A VOC respirator with the cartridge you've shown is next to useless against dust. An N95 dust mask (the cloth/paper ones doctors wear) works better, is cheaper and much more comfortable. But when our staff are working with Hardieboard, we put them in HEPA respirators (same mask as your VOC cartridge, but a pink bag-type HEPA cartridge). We don't use any processes like grinding that produce respirable sized dust. In my view that's excessive for the real hazard, but if it makes people feel more comfortable and less worried, we have no problem supplying them the protective gear.

The last weld shown in the above photos has the following visually rejectable issues...just from what I can see in the photo:

1. Improper profile
2. Lap (as in cold lap or lack of fusion)
3. Undercut
4. Porosity
5. Slag inclusions

I'm sure there are others as well....

Yeah, the standard PPE wandering around in a concrete plant here is a high quality disposable dust mask. Nothing too fancy. If it's high dust contact, full on lab style goggles are also used. Getting concrete dust in your eyes is really uncomfortable.