Fabrication Workmanship during Fit-Up
Fabrication Workmanship during Fit-Up
(OP)
Hi everyone,
During fit up, my welders will grind and smooth the bevel surfaces and adjacent base material.
After which, we will notify the Client for Inspection and the time taken for them to inspect may varies. Sometime 1 day, 2 days or even 3 days.
So we will use a masking tape to cover the surface as it predominantly expose to external environment.
However I was thinking is there a better way than this? Do you guys have any suggestions other than masking tape in order to minimize re-work ?
What are your thoughts? Do let me know.
During fit up, my welders will grind and smooth the bevel surfaces and adjacent base material.
After which, we will notify the Client for Inspection and the time taken for them to inspect may varies. Sometime 1 day, 2 days or even 3 days.
So we will use a masking tape to cover the surface as it predominantly expose to external environment.
However I was thinking is there a better way than this? Do you guys have any suggestions other than masking tape in order to minimize re-work ?
What are your thoughts? Do let me know.





RE: Fabrication Workmanship during Fit-Up
Separate, perhaps unrelated, issue:
Notifying the client and having them inspect the parts is a good idea, and perhaps should be done before the slag is removed. A long time ago, I contracted with a steel center to have some complex parts flame-cut, welded, and machined. We provided drawings of the assembled parts, and also of the flame-cut components, just to make the assemblies easier to understand. The steel center cut the blanks a little large in some places, to provide material for the machinists to remove.
The welder took it upon himself to spend a godawful amount of time grinding off 1/4" of machining stock to make the components agree with our blank drawings before he started welding. We didn't get the call until after he had completed all the welding, and the machinists had nothing to cut away to make the finished surfaces.
A litle better communication, among all parties, would have saved all a lot of headaches. I wish the AWS standards said something about picking up the phone before picking up the damn grinder...
Mike Halloran
Pembroke Pines, FL, USA
RE: Fabrication Workmanship during Fit-Up
I couldn't agree with you more. The masking tape we used leave residue and before Client come and inspect, the fitters will quickly grind them. As our environment in Batam,Indonesia here is quite humid, the joints will tend to rust quicker than normal.
I also do agree with you about communication. It should be one of AWS Essential Variable in Chapter:Fabrications.
Haha. Thanks for the advise.
RE: Fabrication Workmanship during Fit-Up
Best regards - Al
RE: Fabrication Workmanship during Fit-Up
Just a quick search in google brings me to product you mentioned above. Am i correct to say the joint can be now welded even without hand wire brush?
Perhaps for the next job, I can propose/introduce the primer product during our procedure qualification and speed up the work during fabrication stage.
Im located in Singapore (fabrication yard: Indonesia) and I have this strong feeling the product might be available here as well. I try to search for it tmr.
Anyway Thanks Al for the advise. Its a good idea and suggestion.
RE: Fabrication Workmanship during Fit-Up
In my personal opinion, no paint is better than a lot of paint, but some paint can be tolerated except in cases where the base metal has a high carbon equivalency and delayed cracking is known to be problematic. The higher the strength, the less tolerance for any surface contamination. However, when welding those types of steels, i.e., P91 for example, the cleaning requirements would typically call for the bevels to be cleaned with a solvent and ground to bright metal.
Best regards - Al
RE: Fabrication Workmanship during Fit-Up
Thanks Al for the advise.
RE: Fabrication Workmanship during Fit-Up
There are quite a few weldable primers on the market but need to be careful.
Our contractor on the job I am on in Malaysia wanted to use some so I said they could use if they could prove the quality wasn't affected.
We did some fillet tests using FCAW and the welds looked great on the surface but when we fractured the welds the internals were like an aero bar - not good at all,
Cheers,
DD
RE: Fabrication Workmanship during Fit-Up
Do share the brand/maker of the weldable primer you just mentioned.
RE: Fabrication Workmanship during Fit-Up
Interplate 317 by International Paints.
This product may actually be perfectly acceptable for some applications but it didn't seem to work for us.
Note: I have just checked the datasheet and it states excessive DFT may lead to increased porosity in the weld, maybe our contractor had applied it too thick.
We didn't wire brush it off as Al has suggested due to the fact we had a lot of areas where we couldn't get access and we needed to know if it would burn off during welding.
If you do try it please let us know how it went,
Cheers,
DD
RE: Fabrication Workmanship during Fit-Up
Cheers,
DD
RE: Fabrication Workmanship during Fit-Up
I see. Thanks for the information that you have just shared. I will certainly take note of it and advise you guys if I might qualify/test with primers in the future.
RE: Fabrication Workmanship during Fit-Up
RE: Fabrication Workmanship during Fit-Up
RE: Fabrication Workmanship during Fit-Up
RE: Fabrication Workmanship during Fit-Up
The painters tape is a marginal substitute, but it is only "less worse" .
RE: Fabrication Workmanship during Fit-Up
Thanks for the last few comments. I mean this is open discussion. Some of us surely has a positive experience using the products while other may not. This is my objective to gain knowledge between the two different sides of opinion.
Thanks everyone.
RE: Fabrication Workmanship during Fit-Up
Masking tape is no good as as soon as it gets really wet it leaks.
racookpe,
Agree totally about duct tape on surfaces to be welded - however, we use it all the time as it is put on over the single-vee preparation to prevent moisture entering the prep (it never comes in contact with the actual welding surface).
moltenmetal,
Cleaning with abrasive is good idea but once the two pipes are tacked together you cannot get inside - imperative there is no rust inside the pipe when using GTAW process for the root run.
Cheers,
DD
RE: Fabrication Workmanship during Fit-Up
Sorry for the hijack.
Best regards - Al
RE: Fabrication Workmanship during Fit-Up
Any time I use a new product or one that I am unfamiliar with, I try it and test it to see whether it will work with my application.
Any product can be misapplied or misused. Often time people figure if a "little of this is good, a lot will be better." That isn't usually the case, but we must never forget the human factor. We can cure ignorance, but there is no cure for stupidity. Part of management's responsibility is to ensure the workers have the right information and use products as instructed. The ignorance factor is removed. If the worker refuses to follow instructions, it is time to remove the stupid factor by eliminating that worker.
Best regards - Al