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Chromate conversion coating aluminum parts having inserts of steel or other metals

I deal with Alodine 1200s and my question is: Is it safe to Alodine aluminum parts which have dissimilar materials installed in them such as steel helicoils, bushings, dowel pins, etc.?

Thank You,

Mark S Draper
- Central Point, OR

First of two simultaneous responses -- ++

I've never had any problem with chromating parts with pins, helicoils, etc., although they have always been stainless inserts.

Marc Green
anodizer - Boise, Idaho

Second of two simultaneous responses -- ++

We have Alodined parts with hardware installed. Have found that we must use stainless steel hardware because the acid cleaner and chromate solutions will attack and discolor zinc or cad plated hardware. Also must give the parts a good final rinse and blow dry the areas around the hardware to prevent any bleedout of entrapped solution.

Lee Blanton
- Denton, Texas

To my knowledge, racking of dissimilar alloys when anodizing is not advisable. I have not heard of the same for Alodining.

Dado Macapagal
- Toronto, Ontario, Canada

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