Welding Tips and Tricks

Good Morning from Wisconsin. I am looking for some advice on TIG Weldimg some stainless pans. I haven’t done much TIG before. I bid a lot of welding and fabricating and hvac work for a big company and another company welded a bunch of hand railing and miscellaneous stainless work and it looks terrible. So I got approached about doing some of it, I told them I’m not experienced at TIG but they want me to do it anyway. The first job they gave me is making pans.

I bent the pans up of 16 ga. 304. They turned out nice. The corners are nice and tight and weldable. The advice I am looking for is i want to minimize warping and want good bead appearance and obviously be liquid tight.

I recently purchased a Lincoln Square Wave TIG 275 and a variety of cups including a Furick #12 cup. I rounded up aluminum chill blocks to help with gas coverage and heat sink.

I have attached pictures of the pans and am looking forward on what you have for information and ideas on amperage, tungsten size, filler rod, cup size, gas CFH, chill block etc.

Thanks for reading

Red or blue tungsten. Sharp using a 3/32 is fine. #12 cup, 25-30cfh. Amps will be low, try 80% of material thickness. If your box has pulse, even better. 1.5pps, 30% Peak, 10% background.

Weld from open end to closed end. Back purge if you can. 308 filler at 1/16 or 0.045 if your fit is super close.

If you think they'll be more of these to do in the future I'd build a Al or Cu backing, that will not only be a chill block but also allow you to purge the back side, you'll get the best weld and also be leak tight

What’s the best way to make a purge block? Tap an air inlet into a block and drill 1/8” holes in it?

The goal is to have the argon flow at a low rate with even coverage, so as not to disrupt the back side of the weld puddle.
So your idea of drilling 1/8" holes is on track