GTAW Noob project/question

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At work we have a stainless steel table that has a 16" square opening cut in it. The top is only 1/16" thick. They want me to fill the opening with a sheet of SS and do away with the opening, leaving it as smooth and flush as possible. My plan was to tack the corners then the centers and keep putting on small welds around the square until it was 100% then grind it smooth with a flap disc. I cant put in any backing. Is this doable or am I just going to end up with a twisted mess? I would also like to know what the width of my weld should be. The factory ones are about an 1/8th inch.Last edited by Stuckwldr; 12-13-2007 at 09:12 PM.
Reply:as you probably know SS warps... ALOT!!!! if you can, i would say to tack on some "reinforcing strips"... 1" or 2" wide strips of metal, at leat 10 ga (1/8") thick... tack them about 1" from the edge to be welded... both on the table and on the new plate... put a few small tacks every 3"-6" apart... when you are done, bend up the strips to break the beads and grind the tacks off with the other weld bead... this will help minimize warpage... another thing you can do (if you want) is to put some anit-sieze and/or heat-sink gel/paste in the joint between the table and the reinforcing strips... this helps dissipate the heat and trasnfer it into the re-inforcing strips. other than that, you have the general idea... the 1/16" (~16 ga) SS will warp very quickly... i wouldn't do more than a few tacks at a time in one general area... do one corner, move to the next and so on... if you can get a pattern down, it is best to go to the furthest possible point from the tack you just placed. sometimes when the metal needs to be as flat as possible, the guys at the shop will tack on a bunch of re-inforcing strips... the more you get on there, and the bigger they are, the less it will warp is their reasoning... they also use a water-soaked rag to cool the weld down quickly... not sure if that is for warpage or not, but i am pretty sure it is.other than that, just take your time and keep everything as cool as possible... heat=warpage=a pissed off foreman. lolLater,Andy
Reply:Originally Posted by StuckwldrAt work we have a stainless steel table that has a 16" square opening cut in it. The top is only 1/16" thick. They want me to fill the opening with a sheet of SS and do away with the opening, leaving it as smooth and flush as possible. My plan was to tack the corners then the centers and keep putting on small welds around the square until it was 100% then grind it smooth with a flap disc. I cant put in any backing. Is this doable or am I just going to end up with a twisted mess? I would also like to know what the width of my weld should be. The factory ones are about an 1/8th inch.
Reply:I would not tig welding it. Tig has relativly low travel speeds which means alot of heat input. I would use mig and just keep tacking it. Spacing your tacks along ways apart and skipping from side to side until you get the whole thing welded using that method. That is the only way i can see to have minimal distortion. If any at all. Just my two cents. --Gol'
Reply:if its for food prep stuff...  tig  would be better --more control with the heat part just tacking --yes  less chance of prorosity  than mig  but thats my thought and yes a wet rag or spray bottlehave done a few sinks/ prep tables  but any kind of heat sink under it  would be a big help on the thin metaltig is more control of heat and filler than mig
Reply:Weld 1/4ck to 1/2" at a time and do corner 1 2 3 4 1 2 3 4 1 2 3 4 untill done with cooling air between. I have done this in a food are and it can look ok. Good lu Steel Thunder Welding LLC. St. Thomas VI USAMM350PBOBCAT 3MAXSTAR 150 STH375 EXTREME PLASMA6.5 HP COMPRESORDEWALT 18, 24, AND 36 VOLTO/A TORCH SETAND SO MUCH MORE I DONT REMEMBERALL IN MY 2005 2500HD EXTENDED CAB L/B