<VV> DON'T WELD GALVI---unrelated to Corvair saftey

[Garth Stapon]

Hi:

Galvanized metals are commonly welded at a large variety of Companies. Mig is widely utilized. The fume level is nasty due to the lower melting point of the sacrificial coating.

Here are a few tips.

Avoid hot dipped products when possible as the coating thickness is not consistent which may cause excessive spatter. Base metal coating integrity can have a big impact on the result.

Keep your head / breathing zone directly out of the fume plume as the concentration of fume is greatest at that point. This is technique. The tendency is to get in close to enhance visibility. This is OK with uncoated steel, but is not great on galvanized.

Use low heat input and pulsed transfer when possible. This will reduce fume emissions.

Use an argon based shielding gas is it will lower heat input Vs pure CO2.

We now pause for a commercial announcement...

http://www.praxair.com/praxair.nsf/AllContent/A4A06C34E2479B0D85256DDC006BCEC8?OpenDocument

Shielding gas selection makes a difference.

Regards, Garth