[BC] brazing

[Gary Peterson]

I had a friend who did a lot of occupational brazing/welding.  He was pretty
paranoid about working on anything that might contain cadmium.  At the time,
I had access to a well-stocked chem lab and I made him a qualitative test
kit for cadmium.  Years ago, quite a bit of stuff was cad plated.  I don't
have a feel for how common it is now.  It was my friend's understanding that
the vapor was extremely toxic.  I have little doubt, as it seems most heavy
metals, excluding tin and tantalum, form toxic compounds/vapors.

Gary, K?CX
Rapid City, SD

"I made myself very very sick in high school agriculture class practicing
brazing on galvanized sheet metal.  We were in a welding booth but didn't
turn the ventilation fans on.  About 2 hours after inhaling burning zinc
fumes for several minutes I was down and out.  Out of school for almost a
week with severe flu like symptoms.  In later life I have accidentally
welded or brazed galvanized metal OUTSIDE WITH A BREEZE BLOWING and an hour
or so later be a little nauseated with a headache.

If you are welding or brazing and see yellowish white smoke and a yellowish
or white residue around the outside edge of the heated area, you are
heating galvanized material and should use special precautions.

Kevin C. Kidd"