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On Mon, 1 May 2017 07:06:39 -0700 (PDT), wrote:



Whenever you are working with galvanized steel it is important that
you take the necessary steps when prepping the metal before welding.
If you have properly prepped your metal before welding, you will help
reduce your exposure to zinc oxide fumes.

The usually suggested preparation for welding or brazing galvanized
materials is to grind all the galvanizing off!

Welding a joint with zinc still on the area would weaken the weld but who
am I to suggest that you're right?

Smokers have very high amounts of cadmium in their bodies. If you've
smoked for 50 years you probably have the maximum allowable amount of
cadmium in your body. You can get cadmium in your body by touching it. The
amount into your plasma is as high as 0.07%. The half-life of cadmium in
the body is about 10 years if memory serves.

But both zinc and cadmium would normally only accumulate to dangerous
levels at a rate that wouldn't harm you until long after you're dead
unless you're a smoker.
Or a careless welder.
Brazing spelter containing cadmium can make you sicker than a dog in
short order if you are breathing the fumes - as can the fumes from
welding galvanized steel. It only takes a few minutes to get you
wretching and puking and aching to the point you almost wish you
could die.

"galvanised" is galvanic protection - which can include any of several toxic
heavy metals.

Some people here seem to think it can only mean zinc.

The toxic dose of zinc is really quite large.