[intron12]

Hi Guys,

I have trouble in welding distortion in our fabrication. (waving)
basically, we are fabricating clean room equipments
Imagine a box which 6ft in length and 4ft width

the box is being full weld at the lower front and back and causes the base to wave (see attached file)
we are using 2mm stainless steel 304

can you give any suggestions on how to eliminate or reduce/prevent the waving from happening

thanks in advance

[Rick_H]

Stainless is going to shrink regardless of what you do all you truly can do is try to limit the distortion. I'd have it clamped to a welding table and have a piece of copper, alum or bronze as a backer clamped to the joint. I'd do it in small welds and possibly pulse if your welder has the ability. Can you bend that front piece so you don't have to weld the long section?

Here's some 16g I welded together a few weeks back with the method I posted above. It is 2 4ft x 4ft sheets I bent to form a roof then welded together.

[intron12]

Hi Rick,

Thanks for the reply
I have been reading some articles regarding welding distortion, and im thinking of using stiffeners and combination of heat sinks such as copper plate. (but as of now, i only have 0.9 copper plate)

[Rick_H]

a piece of aluminum as a backer will work great as well. I was working on a cabinet today at 16 gauge stainless I used aluminum as a backer bar and some .030" filler I believe I was around 30 amps max 1/16 tungsten gas lens number 8 cup

[Superiorwelding]

I will throw in some ideas. First one is I have clamped a straight edge to the sheet and unclamp it when the piece is completely cool. This is more or less a gamble but it can work. Another is to back step the welds and use a wet rag to immediately cool the welded section down between welds. This has worked extremely well for my limited food grade work, but you will just have to watch for the water getting in between the pieces. The last is the heat sink. Personally I have found that large aluminum bars or billets work very well. They absorb the heat very quickly and I usually keep several of the same size pieces laying beside me and just swap them out when one gets hot. This allows you to move a little quicker as you are not waiting for one alum piece to cool down.
These are just thoughts to consider.

Rick, I love your signature!
-Jonathan

[Rick_H]

Rick, I love your signature!
-Jonathan

Too much? I couldnt think of anything better the other night and figured that would atleast let guys know who they are talking with....Im a test passer

[Superiorwelding]

Rick, I love your signature!
-Jonathan

Too much? I couldnt think of anything better the other night and figured that would atleast let guys know who they are talking with....Im a test passer

Works for me! I think you know a little more than just how to pass a test though.
-Jonathan

[intron12]

hi jonathan,
Thanks for the reply
wont wet rag make the weld brittle?
Im placing a aluminum bracket fro clamping for the lower part and series of thin copper plate on the base.
i will then placed a angle bars for stiffeners in the base(tacked welded ). and just have it removed and polished afterwards.

[Rick_H]

The backing will also prevent any sugaring on the backside since your not purging.