We have operated under the knowledge that it is not safe to spotweld galvannealed due to the toxic release of fumes. Is there any information you can give me on how to proceed?

-- Darlene Freykar (darlene.freykar@flextronics.com), January 31, 2002

Answers

Resistance spot welding does not produce the toxic fumes associated with arc welding of zinc coated steel. In the automotive plants I frequent, there is not a special air filtration system for the spot welders whereas there always is for the arc welders. This may give you a good indication, because they use a lot of galvanized material, and watch the safety issues very closely.

-- David Bacon (dbacon@updatetechnology.com), April 18, 2002.

While I agree that resistance spot welding gives off less toxic fumes than MIG, TIG, or Plasma welding of galvanized and galvanealed materials. One should remember that to obtain a weld the metal does become molten and produces some fumes. Much depends on the amount of welding and cleanliness of the parts. If the air circulation or plant area is not sufficient to disperse the fumes, some type of smoke removal system should be used. Many plants have monitored the long duration that the operators inhale the fumes, and then install smoke removal systems. Others have added fans to disperse the fumes faster. While others have just installed smoke removal equipment to be on the safe side. If Safety is already a concern, I would suggest a smoke removal system of some type.

-- Bob Balla (bbbco2001@aol.com), April 23, 2002.