Just had an interesting thing happen I've never seen. There's a million things this beginner has never seen so I'll offer this one first.

I'm building an alloy dry sump oil pan. I've seam welded all the .063 sides with some success, nothing to buy my retirement on.

Today I attempted to weld this .063 sump to the 1/2 inch flange. I suspect it is beyond the capacity of the 165 but I thought I'd give it a try.

First little 1.5 inch test seemed to work well.

I brought out some C clamps and a bit of hammer to get it back into line and the second try went to **** immediately!

The reduced section cup split and fell out leaving just the torch exposed?

Is this typical and normal degradation or have I done something way wrong??