Galvanized steel has been used for hundreds of years because of its strong protection and aesthetic design. It’s used in places like gutters on homes to even the suspension cables on the Brooklyn Bridge. We know it is a superior product to steel with any other type of coating since it protects the steel from damage in the handling or service process. But, can it actually be welded? And, at what temperature if so?
Welding of Galvanized Steel
Yes, to answer the million dollar question, galvanized steel can be welded. Welding galvanized steel is pretty much the same as welding barre steel. The same volts, amps, travel speed, etc. can be used with some modification when the switch is made from barre steel to galvanized. If the zinc coating is very thick, it may need some more modifications.
Melting Points
One of the main ingredients in the mix of galvanized steel is zinc. Zinc coating melts around 900 ˚F and vaporizes at about 1650˚F. The zinc that is near the weld does not even hold up, it actually gets vaporized.
Regular steel has a melting point of approximately 2,750˚F.
Avoiding Fumes Safely
When in line of defense in dealing with zinc fumes you must be trained and protected properly. Even when welders are working with uncoated materials, it is important to keep your head out of the fume plume and to position yourself relative to the air flow around.
When working with steel that has a thin, uniform galvanized coating, the welder will want to be sure to have the process be gas-shielded. Another important thing to remember is for the flames to be sparse and the shielding gas to be blown away from the welder.
Welders need to be wearing masks similar to painters’ masks. However, there are larger and more protective masks if needed. There are also OSHA regulations to keep in mind as well.
Here are some different mask options:
- 3M (800-328-1667) 9920 Half-Mask, Disposable
- 3M 9925 Half-Mask, Disposable
- 3M 9970 Half-Mask, Disposable
- Moldex 3400 Half-Mask, Disposable
- 3M Whitecap W-8200B
- Racal Airstream AH-17
- Racal Airstream AH31, 33 or 39
- Neoterik CB14-77
- Neoterik MB14-77
- Hornell Speedglas Fresh-Air™
What This All Means
In short, it is possible to weld galvanized steel. However, welders should take proper precautions and follow the same process as barre steel with few modifications in mind.
