Welding Tips and Tricks

I am Tig welding a 2 mm. stainless steel plate for the replacement of the Bainmarie Food Heater.
My welding was good at the first but it begun cracking and I can no longer repair the cracks as it begun to multifly.
I used 50 amps on the welding mach in reverse polarity.
Please share me your knowledge about how to repair my work.
Thanks a lot.
Tom Seat

Welcome aboard! Post up some pics if possible. Also describe your settings ( amps, tungsten type, gas flow rate, gas lens, no gas lens, cup size) the more info you can relate, the faster you will get answers. We have some stainless experts that will be along to help you.

Should that be straight polarity?

Tom,
Welcome to the forum.

The question I would have first is what grade of stainless are we working with here, and in what configuration.

Usually when you're getting hot cracking, more welding just makes it worse. You need to give us more specifics before you keep trying to "weld it out". That's thin material and easy to overheat.

Any problem solved through cyberspace needs to be presented with as much detail as possible, otherwise you'll answer 50 questions to get just one solution.

Len

Thanks for your reply, Jody.

The settings that I used are the ff:
Amps - 45
Tungsten type - MIGA SUPER BLUE (Migatronic) -1.6 x 175mm
Current range - Amp DC -70 - 150
Amp AC - 50 - 100
Gas flow rate - 2,5 bar l/min
Cup size - 7
No gas lens
Filler used - ? ?? stainless steel
Welding Mach - KEMPPI Minarc

I used stainless steel filler but there's no type indication in the box.
Is the filler should be the same type with the base metal? Probably that 's one cause of hot cracking if the two are of different kinds.

Thanks Jody. I appreciate your concern.

You have given us a gas pressure and flow rate. Can't be both. Which is it? If it's flow rate you need to be up around 8 l/min at least.

Most tig wire will have a sticker or a set of numbers stamped on each rod. Sometimes it's hard to read.

And lack of using enough filler can cause stress cracks in some metal.

Coldman wrote:You have given us a gas pressure and flow rate. Can't be both. Which is it? If it's flow rate you need to be up around 8 l/min at least.

Cheers Coldman. Tried to raise up the flow rate as well. Ssame thing happen.

Are you purging the back side of the weld or welding up against a dissimilar bar? Can you give us a pic of the joint and prep so we can see what's going on? Right now we are only guessing.

Is this cracking on the "food" side, or the "pretty" side?

It matters. 316 filler is dandy for the "food" side.

The "pretty" side could be damn near any alloy China can sell under the nickname "stainless".

Steve S