removing oil from metal plates
removing oil from metal plates
(OP)
What is the best way of removing FUCS oil from plates that have just been through a fine blanking process?
My company is starting this process and we are needing to know the best way to remove the oil from the plates. Is there a need for an alkiline wash? Or can we just fine blast the plates?
Thanks,
Cheri
My company is starting this process and we are needing to know the best way to remove the oil from the plates. Is there a need for an alkiline wash? Or can we just fine blast the plates?
Thanks,
Cheri





RE: removing oil from metal plates
Regards,
Cory
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: removing oil from metal plates
I like a caustic solution or detergent. I don't like blasting because it smears the oil and the grit rapidly becomes contaminated with oil.
If you are really interested here are a few pages on the subject. I think I can post this much. If not, contact me directly and I will send them to you.
tom
46. Cleaning Steel Before Brazing
There are many differing opinions in this area. As nearly as I can tell pretty well everyone is right. I recommend Easy Off Oven Cleaner for cleanliness test (see #1 below) because it is easy, cheap, effective and everyone knows it is dangerous. Freud says that caustic solutions can damage the carbide and this is true as well. I think the difference here is the amount of exposure. I do not think the amount of damage done by oven cleaner in a minute or so is significant.
Pretty well all the methods recommended here can be dangerous. I don’t like some of them for safety reason and others are just too flammable.
There are two areas here.
1. Cleaning saw plate, just the steel part before the tips are put on.
2. Cleaning a saw blade after use.
There are two differences. 1. When cleaning saw plate for brazing you have to have the plate scrupulously clean so that the braze alloy will chemically bond with the carbide. When cleaning saw blades you are simply removing the resin, pitch, etc. Saw blades do not have to be clean enough for chemical bonding. 2. When cleaning saw blades you have to account for the affects of cleaning on the carbide tips and the braze alloy holding the tips to the steel.
1. Cleaning saw plate, just the steel, before the tips are put on.
Cleanliness - Testing Saw Plate for Cleanliness
Clean saw plate is essential for welding or brazed tips. New saw plate comes with a protective coating. Used saw plate has its own set of contaminants from use. You must remove this to get the best braze or weld.
Following is a test on a saw plate that was sent to me for analysis. They had tip loss and wanted to know what to do about it.
I took an eye dropper and put three drops of water on the saw plate and it formed a nice, round bubble (left picture.) For comparison I took a piece of steel and ground it with a very rough wheel. You can see the bar on the right of the picture and how the water spread out more. The technical term is “contact angle” (see drawing above)
Close up of the two surfaces above left. The next step was to take cleaner and clean the saw plate. Then I put three drops of water in the clean area (above right) You can see how the 3 drops of water on the left spread out much more than the three drops of water on the right. You can also see how the clean area around the big spread has a different reflectivity than the uncleaned area.
Above left is what it looks like when it is braze alloy on a saw plate. You can see the distinct, steep ridge along the edge of the braze alloy. Another sign is the feathering out from the braze alloy ridge. When the braze alloy doesn’t flow well the constituents tend to separate out and you get some bleed out from the main mass of alloy.
Left is a test of braze alloy in the same areas where I ran the water drop test. (Clean area left and uncleaned right.) I measured the areas of the flow as rough rectangles. Clean was .63” x .41” for .25 sq. in. Uncleaned was .52” x .31” for .16 sq. in. The clean area wet 60% better.
The real difference is that there is an edge on the uncleaned area where it didn’t wet at all. Uncleaned plate wets poorly and parts of it may not wet at all.
Cleaning Saw Blades For Brazing
Saw blades need to be clean before brazing so that you can form a chemical bond between the saw steel and the carbide or other tipping material. You have an advantage with brazing in that the flux and the heat of brazing do perform some cleaning function. However this is not be relied on. Flux is primarily a protectant to keep air from the braze area. A torch or other heat source can change any oils and greases on the steel into free carbon or other unbrazeable compounds.
Cleanliness of all the parts is an essential step to successful brazing. Clean parts braze well. Dirty parts cause trouble. Oil on steel or carbide causes problems a couple ways. 1. It contaminates the braze alloy and makes it less effective. 2. It forms gasses and causes bubbles in the braze alloy. 3. It burns and creates free carbon and carbon compounds. Carbon is terrible for brazing. That’s why so many people use graphite blocks for brazing fixtures.
Saw plate is supplied with a protective coating to prevent rusting. This coating also allows handling. Some saw plate is supplied coated and hermetically sealed in plastic as well.
The science of cleaning is probably most advanced in electronics followed by electroplating. In electronics they count individual atoms to determine cleanliness. In electroplating that is neither possible nor desirable due to the cost involved.
However, in brazing you have a closed joint so that the surface cannot be readily examined. In plating it is much easier to examine a surface.
Three Case Studies
It is very easy to accidentally get parts dirty.
1. One involved parts that were covered with oil. It seems the customer received the parts and then stored them in a chest. The chest was in an area where they were grinding using oil and other fluids. The mist from the grinding eventually worked its way onto the parts. You could actually feel the oil on the carbide.
2. In another case the brazer was using a torch to burn the oil out of the notches on the plate. When you burn carbide or steel with a torch to clean it you do two things. You burn the steel and create metal oxides. This is like painting over rust. You also burn the oil and create ash and other compounds from the burnt oil. This is like painting over rust that is also dirty.
3. There was a third case where the customer was sandblasting to get oil out of the notch. Sandblasting does not generally remove oil very well. It tends to contaminate the sand and make oily sand, which spreads the oil over everything.
Much of the following comes out of our work in electroplating. Fortunately it is easy to apply this technology to saw blades.
Cleaning has two parts.
Number one is physical removal like blowing leaves off a sidewalk. Number 2 is a chemical reaction such as using hand cleaner to get grease off. Water is a solvent and will dissolve many things such as sugar and salt but it will not dissolve oil and grease. The same thing is true with any solvent you use. Whatever cleaner you use it will almost certainly work better with some physical removal such as brushing, wiping, high pressure spray or similar.
There are basically three kinds of materials to be cleaned off saw steel.
1. Organic soils (A chemical term meaning carbon based) such as lubricants, oils, greases, polymers and similar, which are usually spread in thin films and may not be visible.
2. Inorganic soils (not carbon based) including heat and weld scales, carbon, dust, rust, oxides and similar form on surfaces exposed to air and can be worse at elevated temperatures.
3. A mix of 1 and 2. this can include buffing compounds, fingerprints, shop soils, marking compounds. These can be the most difficult to remove.
Selecting the proper cleaner is necessary to remove specific soils efficiently and effectively. Carefully consider the following factors:
Considerations in cleaning
1. What do you want to remove
2. Underlying metal – you can use caustic cleaners in steel but they will react aggressively
3. What are you truing to achieve – how clean, how rough, etc.
4. What has been done before – have the grease been heated and baked on
5. How big and what shape is the area – Do you need a can of spray cleaner or a dip tank.
6. Cost – equipment, processing and disposal
7. Health and safety
Cleaning Steel for Brazing
Tools Spray on left and wipe on right After rinsing
This is an old saw plate sprayed with WD 40. A thick, water based ink solution was poured over it to show the underlying grease. The left side was sprayed with Easy Off oven cleaner and the right side was wiped three times using a paper towel soaked in acetone. In the middle picture you can see the oven cleaner bubbling up on the left and the streak marks on the right from the acetone wipe. Finally the plate was rinsed under running water. The oven cleaner side rinsed clean and the acetone left side has streaks.
Solvents are not cleaners. They can be used to clean but that is not their intended use.
This is a picture (left) of the braze joint where carbide (top) is attached to the steel (bottom). The braze alloy balled up between the steel and the carbide. Both sides were dirty so the braze alloy did not stick well to either side. You can also have steel or carbide that is not completely clean and it won’t show up on the sides. It will create pockets inside where the alloy doesn’t stick and that means weak joints. Carbide that came off showing pockets in the braze alloy (right.)
Solvents
Solvents used to be great cleaners. Now most of the really effective solvents are illegal.
Solvent cleaning is a process of dissolving the materials covering the steel. The more often you repeat the process, the better it works. If you get 90% the first time then you will get 90% of the remaining 10% the second time for a total of 99% removal. You never get it all but you can get it clean.
Solvent comes from dissolve which means to merge with a liquid. The idea is that you dilute the oil and make it easier to wipe away. However, you are only dissolving the oil so there will always be a little remaining even if it is in a much smaller concentration. Also, the oil sticks to the saw plate and a solvent dissolves from the top down so it does not get under the oil and remove it.
You have to know which solvent to use. Water is an excellent solvent but it won’t touch oils and greases. Acetone, alcohols and other common solvents do not dissolve everything no matter which one you use. The old solvents that used to be very effective are now largely illegal. Vapor degreasing has often been replaced by wiping with methanol or a similar process with a great reduction in both quality and reliability.
There are also modern protectants, many plastic based, that are much more solvent resistant than the older, traditional petroleum and animal based protectants.
Easy Off makes soap
The sodium hydroxide (caustic soda) in Easy Off mixes with the oil or grease to make soap. Dishwashing detergent and laundry soap use the same process but they use milder chemicals than oven cleaner does. Another example of this process is the old-fashioned method of making lye soap. It called for mixing lard with lye and cooling the mixture to form soap.
Soaps and detergents
Molecules of detergents are long and thin, like a match. The head end dissolves in water and the tail
dissolves in grease. When something greasy is washed in detergent, the grease-soluble tails plug themselves into globules of grease. They surround it and form ball-shaped micelles, which float the grease, into the water.
Ultrasonics
Ultrasonics can be extremely effective. However ultrasonics just apply energy to help the chemicals work. How you load the machine is very important because these are sound waves and can be blocked by corners and walls just as voices are. In addition the ultrasonic echoing effect in the tank can be either good or bad. Also thick grease probably attenuates the sound, causing it to deaden and decreasing its effectiveness.
Vapor degreasing
Chemicals used in vapor degreasing are most effective when they go through the evaporation and condensation cycle. When used merely as solvents they lose a great deal of their effectiveness.
Cleaning the Saw Notch Before Brazing
The best way we have of explaining cleanliness to brazers came from a customer. He said just tell them it’s like painting a car. You have to get to clean, bare metal. Nobody who was serious about doing a good paint job would just go out and start spraying. You make sure all the old paint is off. You make sure the surface is really clean. You make sure that the surface stays clean while you are painting.
In brazing you have to have clean carbide and clean steel and keep them clean.
How to braze good saws
1. Clean steel and clean carbide
2. Rough steel and rough carbide
3. Good solder and keep it good. No contamination
4. Enough heat but not too much - see fillets
3. Not too thick a joint
4. But thick enough
5. Good fillets
A lot of times the saw tip will come lose from the saw body because the notch was not properly prepared. A dirty notch can leave oil and grease as well as grinding dust and general dirt. Anything (repeat anything) left in the notch will cause a weaker braze joint. It dilutes and contaminates the braze alloy. It prevents chemical and physical bonding between the braze alloy and the steel or carbide.
The most thorough method I have heard of was given to me by a customer who never has a tip loss problem.
1. Grind the notch smooth, flat and square. You can buy sandblasted plate but sandblasting rarely removes the full amount necessary for good joining. When the plate is laser cut there is a heat affected zone about .003” to 0.004” deep that has to be entirely removed.
2. Wipe the notch with a clean cloth. Clean means no oil, no dirt, no greases, no dust and no fabric softener or sizing.
3. Remove all oils and greases with a caustic solution or something with an equally good affect. Solvents are not recommended.
The essential thing is to provide a clean flat, smooth, surface so that the braze alloy can chemically and physically bond to the steel. Grinding the notch will remove heat scale. Wiping with a clean cloth will remove a lot of the film and oil. The final dip will clean the surface.
There have been questions about whether the notch should be “rough” or “polished” since I use both terms above. A common braze joint thickness for saws is about .003” (3/1,000). With this in mind then anything under .0005” (5/10,000) ought to be good. If the final joint is .003” then you do not want anything over .001”.
You must remove all oil and grease. It is essential to remove oil and grease for a lot of reasons. An oily base metal will repel the flux. This will leave bare spots that will oxidize under heat and create voids. Oil and grease will also carbonize when heated and form a film that prevents solder from flowing over the carbonized areas. The carbon will contaminate and weaken the braze alloy. The oils and grease can vaporize and cause bubbles in the braze joint.
Summary
Cleanliness of all the parts is an essential step to successful brazing. Clean parts braze well. Dirty parts cause trouble. Oil on steel or carbide causes problems a couple ways. 1. It contaminates the braze alloy and makes it less effective. 2. It forms gasses and causes bubbles in the braze alloy. 3. It burns and creates free carbon and carbon compounds. Carbon is terrible for brazing. That’s why so many people use graphite blocks for brazing fixtures.
Tank maintenance
Use deionized water or softened water to mix coolant. This avoids the build up of hard water scale as water evaporates over time. The longer you want your coolant to last, the more important it is to use deionized water.
Control oil buildup. Use a skimmer or throw an oil absorbing pillow in occasionally.
More Information:
http://www.cleanersolutions.org/ - Cleaning solutions and solvent substitutes
http://www.mntap.umn.edu/ - University of Minnesota, Minnesota Technical Assistance Program
Pico clean - http://www.picochemical.com/
Ram cleaner - http://www
47. Cleaning Saw Blades
A. This information is my own research and from a discussion among professional saw shops
Saw Cleaners
It is important you clean saw blades before brazing or welding tips. The questions come up as to what is the best cleaner.
Sawfiler Opinions
Victor Da silva
I came up with the tank cut in half & water heater element years ago, except I used an old galvanized pressure tank, which had thicker walls. I use Saw Kleen, distributed by J Tool Express, which, according to the manufacturer, works better when heated. Heating any solution will help soften the pitch & gum, making it easier to brush off.
That being said, I eventually moved up to an ultrasonic tank, which really works great. I still use the Saw Kleen and heat it to about 175 degrees. Brand new units can be costly, although they are a great investment. I searched E Bay for a few weeks until I found a unit that could handle 12" blades laid down or 14" stacked on an angle. I put my saw blades on a galvanized carriage bolt with washers in between and can fit several stacks in at the same time. Nasty old chain saw blades have the gunk brush right off and the hose takes care of the rest.
Bob Cook
You can buy sodium hydroxide/Lye at most janitorial supply houses in 50 # bags for around $2.00 a pound. A stiff wire hanger suspending each individual saw blade from a rod across the top of the open drum will allow you to soak more saw blades at a time without the weight when removing them. A good machine coolant concentrate in the rinse water will let you drip dry the blades without rusting.
Mr Neil Franklin, Marietta Saw
Removing residue on plastic and Corian-cutting blades. I use a very concentrated solution of NaOH (sodium hydroxide) to loosen it, and then wearing long rubber gloves, I scrub the blades with a stiff plastic bristle scrub brush. What doesn't break loose with that procedure, I'll hit with a wire wheel on a bench grinder.
Rob Rzasa, Equipment Ltd.
We have a very good machine that will clean all types of blades and tools. We offer an ultrasonic tool cleaner in two sizes, one for saws up to 16" and another unit for saws up to 26", both machines will clean in excess of 24 to 36 blades at a time in about 5 to 7 minutes.
The easiest thing to find is: Red Devil Lye. A 16oz bottle costs about $ 4.00, we used to get it at Lowes but not every store carries it. The last time we bought some, we got it at Home Depot.
David Farris
I just ordered a drum of powder from ZEP with product number 9878 and is called heavy duty vat stripper and it says that heating the mixture works best.
Stan, Aksarben Saw & Tool, Inc.
I too use a solution of sodium hydroxide, however maybe not strong enough. Then we wash with soap and water, clean the edges, and polish the plate.
R.S. Ponton, ICE
Cut a 52gal steel drum around its "belly" forming 2 half tanks. One is used as a cold water rinse tank and the other is used as a heated sodium hydroxide (NaOH) soak tank.
The NaOH soak tank is constructed as follows: Purchase a 220V hot water heater heating element at a hardware store. It must be the straight type, a not folded-over type. Mount
it into the side of the tank at the bottom.
Drill random holes in a length of pipe which is long and large enough to cover the exposed length of the heating element inside the tank. This pipe serves as a physical protection guard for the heating element when sawblades are immersed into the tank. Mount it inside the tank at the bottom covering the exposed heating element. Wire the 220V heating element through a standard wall mount light switch and connect to a 20Amp 110V outlet.
Fill the tank with water and add about 6lbs of NaOH. Exercise care because NaOH is a very strong organic solvent.
The heating element can be left on all day and it will not overheat. No regulating thermostat is necessary because the element is 220V but powered by 110V, it provides an ideal soak bath temperature. It is advisable to switch-off the heater at night and on weekends. The heating element typically lasts about 5-6 years before needing replacing.
After a 5 minute soak in the heated NaOH tank, gummed sawblade are quickly cleaned. The worst gummed sawblades might require a few light strokes with a plastic bristle brush.
Add water and NaOH as necessary to maintain a full tank and a saturated solution. Change the solution periodically as residue accumulates in the tank. The solution can be dumped down the drain because it is the equivalent of Drano(tm) and should contain no hazardous products.
A handy "carrier" for holding the sawblades being cleaned can be fabricated as follows: Bend a 24" length of 3/8" steel rod or "all-thread" into an "L" shape with the foot of the "L" about 4" long to serve as a handle. Weld the straight end vertically in the center of a steel plate about 1/4"T x 1-1/2"W x 6"L. This carrier provides a simple means of containing a stack of sawblades while immersing them into the soak tank, the rinse tank, etc.
Stan, Aksarben Saw
Our shop does not heat the mixture. I use heavy rubber tubs used for livestock, big enough to lay 18" blade in the bottom. (Local farm supply store) I made a rod for holding the blades out of 1/2" rod with a threaded end on one end and a small plate welded to the other end. (about 16" long) I made T handle that screws to the theaded end. As we stack the blades on the rod we space each blade with 2" washers made of plastic mud flaps (Local truckstop gives them to us free) This whole arrangment is stored in a lockable cabnet.
Ed Bissell
For information only you might want to be careful what you put down your drain. Several issues to consider;
1. What is it going to do about the working bacteria system of your septic tank.
2. Is your system large enough to handle the volume your going to put in.
3. Last but most important, anything you discharge from your shop is considered industrial waste and must be disposed of properly. Big EPA problem if not handled correctly.
TSP (Tri Sodium Phosphate)
Marty at Carbide saws, Inc. in High Point, NC sent Emily a sample of this with a great drawing just in case Emily didn’t know how to scrub saw blades. They mix 1 pound per five gallons and really like the results.
Our Tests
Dip Tanks
There are a variety of chemical preparations available. Oakite #3 is a product that was recommended to us. It is effective on oxides and scale as well as oil and grease. Oakite is in New Jersey at 908 464-6900.
Pretty well any strong caustic solution from a janitorial supply will work. The problem with caustics is the danger. Hot caustic can burn skin and eyes. Working with a dip tank can make the danger much worse.
Caustic is popular and effective so we tested Easy off oven cleaner in spray can as well as “Oven & Grill Cleaner” from our local janitorial supply house.
Citrus based
We have been hearing good things about these so we tested a couple.
Citrus – from Orange Fresh and
Orange Clean form Orange Clean
We also tested 409 as well as Simple Green and Brakleen
$ / oz.
Brake cleaner - spray can 0.33
Simple Green 0.24
Caustic - Spray cans 0.23
Orange Clean 0.15
409 0.12
Caustic - spray bottle 0.10
Citrus - spray bottle 0.09
Citrus - spray bottle 0.06
One stood out for being really horrible: Brakleen is far and away the most expensive. It is the worst cleaner, it causes cancer and it can explode.
This is a great product for getting in very tight spaces and dissolving greases and other packed crud. However this is not what we are doing with saw cleaning. We want to dissolve a thin layer of light materials on a flat surface.
We tested the sprays with a 2 second spray and 8 wipes. We tested the liquids by holding the towel over the top of the bottle and tipping it to soak a patch on the towel and then giving that 8 wipes.
The cheap oven and grill cleaner was far and away the best cleaner followed by the Easy Off then the orange cleaners (no real difference among them). The 409 and Simple Green were not as effective and Brakleen was the worst at cleaning.
Safety
Brakleen is Carcinogenic as well as having other problems. All the rest cause skin and eye irritation. It looks like the caustic might be worse than the citrus which might be worse than the 409 and Simple Green. All recommend gloves and goggles. Aprons are a good idea and some recommend them. Brakleen mentions a respirator (not just a mask) if there is a possibility that the exposure limits maybe exceeded.
Basically the stronger they clean the more likely they are to irritate skin. Skin has oil sort of like any other oil so this makes sense.
Advice:
1. For best cleaning use a strong caustic such as an oven and grill cleaner.
2. Avoid brand names. Most of the extra ingredients are to make it easier to spray. You also get butane as a propellant and spraying butane in a saw shop doesn’t sound like a good idea.
3. We know one very good shop that uses an orange cleaner and likes it because they don’t have to rinse it off. Caustic compounds can be a bit hard to rinse.
4. Buy concentrate and mix your own. You can drop your cost in half and you can get the mixture you wish.
Two Additional Cleaners
Ram Cleaner & Picoclean 123 orange
Because cleanliness is absolutely essential to successful tipping we have done a great deal of research into it. Whether you are brazing carbide or welding on Stellite® tips you need a clean surface. Any oil or grease can interfere with the join and cause tip loss.
Picoclean is a highly advanced version of the traditional caustic cleaners. Ram cleaner is heavily solvent based with some caustic cleaner.
Some customers are using straight caustic cleaners such as Lye, caustic soda or sodium Hydroxide. Others are using a solvent such as Acetone, alcohol or simi
RE: removing oil from metal plates
that might provide some help. there is a lot of other stuff on this site that may help.
RE: removing oil from metal plates
If the oil may contaminate subsequent coating, brazing, or welding operations, you need a solvent cleaning. This needs to involve some kind of rinse to lift the oil and solvent away from the steel. For some reason I keep encountering people who seem to think solvents are neutralizers, and they spray solvent on the oil spot and rub it with a rag and don't understand that all they've done is make a bigger, thinner oil spot.
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies
RE: removing oil from metal plates
RE: removing oil from metal plates
In many areas you need an environmental permit to operate one.
RE: removing oil from metal plates
I prefer a caustic solution since I have seen many, many problems with solvents used improperly. It seems to be a common understanding that any solvent (e.g. alcohol, paint thinner, acetone, Brakleen, etc.) will remove any grease.
This is a big deal in the saw and tool industry. Moon’s and Colonial saw both make machines.
Tom
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
RE: removing oil from metal plates
Here is information on the Dupont line of Vertrel solvents.
You shouldn't have any regulatory problems with this material.
The pdf describes the Vapor Degreasing Process.
http://www
http://