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What is the best pretreatment for Duracoat?

Q. I am looking to do a Duracoat on some small parts that I am making. The Duracoat is provided by www.lauerweaponry.com. They suggest that I get the parts parkerized before applying the Duracoat. I'm in the middle of the machining process now, and would like to know a few things before I go ahead with the finishing process.

1. What exactly is the industrial name for Parkerize and DuraCoat? I thought Parkerize is a type of zinc/manganese phosphate, but I can't be sure.

2. Any alternative to parkerizing as foundation for the DuraCoat? I can't find any vendor around me to do the job (parkerized or zinc/manganese phosphate) and I'd prefer to have someone handle this professionally.

A. Hi Minh. You are right that over the past many decades the phrase "Parkerize" has become so slang-ified that it is hopeless to try to put a fine point on it. Many people insist that it means manganese phosphate, many insist it is zinc phosphate, and both groups cite historical literature to prove their claim :-)

If you are applying a proprietary coating like Duracoat, you really ought to ask them to spell out exactly what they want for pretreatment, rather than presenting it ambiguously -- but I'm pretty confident that a conventional zinc phosphate pretreatment will be just fine, and so will the less common manganese phosphate. Good luck.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2015

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