Post subject:Welding/fininshing SS for commercial kitchensPosted: Jul 27, 2008 - 01:21 AM #7742
Joined: Jul 27, 2008
Posts: 1
Hey there,
I am a new member of the sheet metal shop!
I saw your response to the topic of grinding and sanding stainless without warping. I have a few questions about this topic. To give you a little background in what I know and have done; I am a welder who doesn't usually do much sheet metal. I find it very frustrating due to how it warps so easily. I have tried 5 different butt welds on some tables/counter tops in commercial kitchens and a 2 dishwashers troughs in SS work station tables.
I have issues with warping when welding and grinding.
-I am using a Miller Dynasty 300 DX with scratch start (not my equipment and I hate TIG welding without a foot pedal). In the past I have used vise grips with 1/4 long aluminum channel on each side of the seam.
-I tack the seam with no gaps and making sure the two surfaces are even.
-I then slowly weld it every inch or so and have to cool it down with water from the back side in order to pull it opposite of the welded side.
-After it is welded then I get to the part I absolutely dread is grinding and polishing it. I can do fine except the occasional underfilled spots or where it buckled and I have to take a center punch and hammer backed up with a flat piece of steel a hundred times.
-I am using a large 9 inch grinder with some various grit flexable disks to get it flush. Then I go over it with one of those multiple layered sanding wheels to get the grain. It does a decent job, which is exceptable by the guy who hires me to do the work.
-As I grind I have to make a couple of passes and then start cooling it down with water on the opposite side to get the bubble out.
My question is by reading this what can I do more to prevent warping.
-Do I need different tools
Such as hammers and dollies
-Do I need to put a bar on the back of the weld
-Do I need to clamp it down better
-Do I need better grinding equipment
-Are there better ways to remove the weld without grinding
-Do I need to change my welding amps, I have tryed any where from 35-50 amps with 1/16 309L filler.
I know that you said to put a 1/4 gap at the end of the weld, but that seems like a huge gap, unless it shrinks that much as you weld it.
If you can give me any suggestions I would be greatly appreciative because I have a few jobs coming up really soon.