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  for Metal Finishing since 1989
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Gel Passivation

We are process vessel manufacturers and have been asked to "gel passivate" the external surfaces of a small vessel. What is gel passivation?

August Cook
- Syracuse, New York
2001

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They are most likely referring to a hexavalent chrome conversion coating that is used to passivate zinc or zinc-alloy platings. This conversion coating is only angstroms thick, but it is a hydroscopic gel. This type of passivate is part of all typical zinc or zinc-alloy platings.

Tim Neveau
Rochester Hills, Michigan
2001

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Mr. Cook:

There are gelled products on the market for "painting" onto the surface of stainless steel where immersing in a tank is not possible. We market safe and environmentally friendly products based on citric acid to do this, if you need help. These products produce a surface which does not have free iron or other exongenous materials on them, and improves corrosion resistance dramatically, especially in the weld areas.

Regards,

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2001