Welding technique

[jimrockireland]

I am stick welding with a Lincoln 225 AC stick welder. When doing a standard flat weld is it OK to re-weld (re-liquify; back track) a section of the weld in the same pass for the purpose of building up the weld a little more? When welding over a previous weld is it OK to just remove the slag with the hammer or should you grind the previous weld first.?

[DesertRider33]

You should stop and chip off the slag before welding back over where you've been, since the slag has likely already solidified, if I'm understanding your question correctly.

Unless there's porosity, slag inclusion, non fusion, etc defect that needs to be ground out, you can put in subsequent passes without grinding. Scratch/chip/brush off the slag and weld.

[i4sillypwr]

I think he's talking about whipping back into the already solidified puddle during the weld. I think....if so that depends on the rod and who you talk to.

[tanglediver]

The time it takes for weld metal to freeze is very short. Not much after that, the slag hardens up. That slag needs to come off before you add another bead.

[Taiden]

if you're talkn gabout whipping (ie, while you're laying an arc, go forward, then step back *slightly*, then go forward, and repeat)

that depends on the rod and what you're doing. For example, 6011 we are told to whip in class, but 7018 we are told not to (can't remember polarity)

[jimrockireland]

I was referring to what i4sillypwr describes: whipping back into the already solidified puddle during the weld. I have noticed my welds seem to be pitted. I am welding 1/8 inch mild steel using 6011 3/32" rod at 60 amps.

[i4sillypwr]

You shouldnt have a problem whipping 6011. Amps seem a little light which could cause your problem but not all machines are the same so i dunno. I'm not the most experiance stick weldor so hopefully someone else will chime in.