Welded a lambda boss onto my mates exhaust the other day, it is mild steel and 1.5mm wall thickness tubing, I think I was at about 70 amps.
any idea why it is black?
comments welcome
Exhausts are often made from aluminised sheet and tube, the colour of that material suggests to me that it is, your black weld is likely contaminated by the aluminium coating,
I wouldn't worry about it will be sound enough.
