Tig welding stainless flange to a pipe.
Walking the cup--Welding a stainless flange like this just begs for walking the cup. It’s a perfect joint. The tig cup just slides back and forth with no hiccups and the final weld looks like a machine welded it.
I like to freehand with the tig torch most of the time... but for a joint like this one…I would walk the cup too.
Why? Because I can hold the torch back away from the heat and because I can make it all the way around the joint without even coming up for air. If you were to freehand this joint ( and what I mean by freehand is to slide your glove along the joint, lightly propping in the flange), you would most likely need to stop occasionally just to let your glove hand cool off.
Discoloration of stainless steel---see all the pretty colors? That usually means things are going well.
Blue, purple and straw are all normal colors on a stainless weld like this.
It’s the grey and black color that is not good.
The colors let you know that the metal has a chance to cool off enough before the argon shielding coming out of the tig cup leaves the heated stainless.
….and do you see that huge cup on the tig torch?
It looks like a gas lens type and it is much bigger than most welders would typically use for this weld. . But that big cup is definitely working and the final weld is hard to criticize.
Its good ….Really good. The ripples are just a little loose for my taste but Still...Really good.
Brush between passes and when you are done.
—always use a stainless steel brush on stainless steel.
Otherwise, you will cause rusting at some point in the life of the weld. A trick for brushing is to wire brush the weld before it cools too much. Not while it is too hot, buy definitely before it cools, You should be able to feel the tips of the wire bristles drag just a little. Try it and you will see the difference in wire brushing a cold weld and one that is good and warm.