Small stainless pot repair guidance

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Hello,A friend threw this over the fence and asked if I wanted a shot at the title repairing this small stainless pot.  They use it for holding tomato sauce when cooking pizza's in their outdoor brick oven - given the delicousness of those pizza's I want to get this right!  This is a great "no worries" project - if it goes south they just buy a new one - so nothing to lose.  Looking for your guidance - I have a TIG machine and stainless rods - just ordered a dual flow regulator and purge hose from Weldmonger's site (this project was my excuse to finally pick this setup up - just sayin)Appreciate your advice -  I'm going to grab some really thin stainless just to test out some amps and flow with a butt weld - I can just about squeeze the crack back together - not sure if maybe that and just fusion welding it back may work, anticipated taping the top shut with the hose inserted - assume I must also allow for venting too or is the crack I'm welding shut enough to vent through?How about finishing afterwards to blend together (assuming I don't destroy this thing!)



Reply:The way that I would approach this is take 1/8 inch aluminum Hammer form to the inside to be used as a backer.  Put a liberal amount of solar flux on the joint to be welded.  Clip the aluminum backer.  I would use high amperage pulse with a short on time to do the weld with something like .035 wire lay wire.
Reply:I'd guess the pot's skin is maybe 0.020" thick, perhaps less, based on similar containers I have. If you don't have lots of experience welding that thickness, it might be safer and easier to silver solder a strip of thin stainless over the crack. A propane torch could even supply the heat needed for that. In any case, I'd first slip a short (already curved) piece of close-fitting stainless rod into the top rolled edge; that area could either be welded or soldered together to add rigidity before working on the crack below.
Reply:Use a rachet strap to squeeze the joint together and put a tack on top to hold it. Then make up a small purge chamber from some small angle to wedge or foil tape against the inside.  Repair weld with pulse, 2.5pps, 50% on time, 50% background current and using peddle. Use 1/16" wire to start at the end of the crack and work your way to the rim fusing and dabbing as necessary. Do an inch at a time and let cool in between. If it keyholes, stop and let cool before continuing.
Reply:Will you need to passivate?  Given it is cooking tomato sauce. Probably need fillet to keep it cool tooGood luck, seems like you have a plan.
Reply:The item is so small, possibly put the entire pot in a box, and purge the box with heavier than air inert gas,, (NOT helium,, etc,,)do the welding while the pot is in the box.If you purge the box just right, there is a very good chance that the weld will not oxidize much, if any,, especially at the back of the weld.
Reply:Yes, you need an outlet (exhaust) for the back purge, otherwise as you close off the seam the argon purge will have nowhere to go and could blow out the weldmaking a mess. I would weld a short length and stop and let it coolRichardWest coast of Florida