green stuff on weld
I've been welding some pipe together for a body rotisserie and noticed several welds had dark green stuff around them. Is this some kind of copper or chromium contamination?
Conditions: Lincoln AC 7018 rods, 5/32", welded with a 'buzz-box' at 175 A, pipes: 1 rusty 2-1/2", 1 new 2", grinder used to clean both where welded.
Attached image: 1332x792 close-up of green stuff