Remove galvanizing before welding

[tomtucson]

Just wondering about removing the galvanizing from steel before welding. Would some NMD 80 or other acid do it or is there a standard method or should I bother? I'm using flux core mig wire.

 

[Guy Blackmon]

Grind, sand, media blast, high speed wire brush. Not sure about acid or NMD 80.

I do know that if you inhale the galvanized smoke when welding you'll get "Killer" headaches.

 

[Scott Stone]

Acid will take it off, but a grinder or sander is better.

 

[tomtucson]

I know about galvanic poisoning, and I saw that years back the welding union required something like one quart of cold milk per hour because calcium is the antidote so I always down a few tums before I start. I was thinking it makes it harder to weld because it splatters more and there's the poison smoke also.

 

[Guy Blackmon]

You're right Tom, trying to weld on top of it makes a holy mess. Weld will not hold. We always used a grinder and then gray primered over the weld when it cooled.

 

[BlueBliss]

grinder! Even still, I'd wear a respirator and setup with a fan or other serious ventilation.

 

[Paul Kassander]

I agree grind or blast I think the acid would really have to be strong to take that off.