Zinc (Galvanized Steel)
Glass artists most commonly come into contact with zinc in the
form of a coating on galvanized steel. (It's often used on the
outer surface of metal buckets or garbage cans.) The value of
a galvanized coating is that it helps stop the steel from rusting.
Although some galvanized items have shapes that can make
interesting slump molds, it's a good idea to resist the temptation
to use them in the kiln. The zinc burns off the item at around
750 - 800F (400 to 425C). More importantly, zinc fumes can be
irritating to the skin and eyes, and respiratory tract.
Symptoms may include watering and redness in the eyes, itching,
coughing, shortness of breath, and sore throat. Even worse,
prolonged contact or inhalation can lead to chills, fever, pain,
nausea, and even vomiting.
Bottom line: don't put items that are coated with zinc
in your kiln unless you follow all safety precautions. Use a
respirator. Vent your kiln and stay out of the area as much as
possible. If you have an exhaust system, use it.
Even better, find another material to use for a mold.
Copyright 2006 Brad Walker.
All rights reserved.