[arnolddyer]

On my Hobart Handler 120 I have a reverse polarity option. I have never used this. When is it necessary to do this ?

[taylorkh]

Reverse polarity or Electrode Positive is used for solid wire MIG (GMAW) welding with shielding gas. Straight polarity or Electrode Negative is used for self shielding flux core (FCAW). You would need to change the polarity when you change the wire type.

Ken

[Otto Nobedder]

Ken's correct.

I'll add that there are "dual shield" wires, that have a flux-core AND require gas. Some are straight polarity, some reverse, so it's best to check the maker's recommendations for these. I doubt you'll find one for a smaller machine, though. I've never seen a "dual shield" wire under .045"

Steve

[arnolddyer]

Reverse polarity or Electrode Positive is used for solid wire MIG (GMAW) welding with shielding gas. Straight polarity or Electrode Negative is used for self shielding flux core (FCAW). You would need to change the polarity when you change the wire type.

Ken

Okay Ken, If I understand you correctly, I use grounding clamp neg.and electrode (gun) positive for shielding gas mode operations. Then when my gas is off for flux core operations I would make my grounding clamp positive and my electrode (gun) neg.?

[arnolddyer]

Ken's correct.

I'll add that there are "dual shield" wires, that have a flux-core AND require gas. Some are straight polarity, some reverse, so it's best to check the maker's recommendations for these. I doubt you'll find one for a smaller machine, though. I've never seen a "dual shield" wire under .045"

Steve

Thanks Steve,I think the biggest wire I would be using is the .035. I actually prefer the .023 because I tend to weld mostly sheet metal. Thicker stuff , if not too much, I'll stay with the .023. If I have a lot of thick metal welding I will switch over to .035, that's the biggest my machine is designed for use.

[Otto Nobedder]

You have it right.

As Ken said, for solid wire with gas, the gun is positive.