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"Galvanization of Wire Problem"
June 29, 2016
I am working as an intern in a galvanizing plant. The equipment uses asbestos wiping technique to control zinc coating. It involves annealed steel wires having diameter 0.9 mm. A specified number of wires (15-18 for galvanizing wires having diameter ranging from 2 mm to 2.50 mm) is taken and asbestos cords (3 mm thickness) is wound on the annealed wires in a conical shape over a length of 2.5 inches. This preparation is then wound up on the wire and tightened before it is let into the zinc bath.The wiper after coming out of the bath gets clamped into a die comb and is fixed there such that the wipers remove free zinc from the galvanized wire surface. Since it is a manual technique,there are frequent coating variations which exceed the required coating limits. Please suggest some alternatives to deal with this situation.
Student - JAMSHEDPUR, INDIA
Hi Alok. What are those "required coating limits"? If significantly lower than what the hot dip process inherently produces, you might consider switching to zinc electroplating where the thickness is relatively easily controlled.
Ted Mooney, P.E. RET
Aloha -- an idea worth spreading
finishing.com - Pine Beach, New Jersey
P.S. opinion! In looking for videos of wire galvanizing I realized that the manufacturing jobs are never coming back to America if free trade continues to mean farm the labor out to anywhere in the world. This is what American shops looked like when I graduated almost 50 years ago.
I well remember being warned "Be careful and duck under the wire quickly because, if it gets a kink or loop ..." Remember those days days when you frequently encountered people with missing fingers?
OSHA and the lawyers have achieved some good and some bad, but America will never return to this nor be able to compete against it. And the Trans Pacific Partnership will ensure that as India, China, and Mexico become wealthier and no longer work this way either, there will always be a poorer place the corporations can ship the jobs to that we can't compete against :-(
July 4, 2016
Q. The coating requirement ranges from 50 grams per meter to 70 grams per meter. The coating usually crosses these limits (over as well as under coating).The wiping used is pig tail wiping and electroplating cannot be implemented. Please suggest changes either related to wiping technique or to the HDG process.Alok Singh
- Jamshedpur, Jharkhand and India