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  for Metal Finishing since 1989
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Bright, Reflective Surface Treatment for Magnesium

2006

I am looking for options for obtaining a silver, relatively bright/reflective surface treatment for some magnesium parts. The parts are bicycle suspension lowers, also called "sliders." They are approximately 2 feet long. ODs are roughly 2", IDs 1.6" Each slider has a core aligned bore hole that requires a precision bearing fit between the inside of the slider and a press-fit bronze sleeve bearing. There are also precise, seal lip retention lips at the top of the sliders. So the ability to mask the tops and inner bores of the sliders is highly desirable. The outer shape of the sliders are somewhat irregular due to design requirements and the two "legs" are connected by a brace that is part of the casting itself (not a bolt-on fork brace).

While many motorcycle fork sliders are aluminum and can be polished, virtually all modern bicycle forks are magnesium. Not only is the polished finish of magnesium marginal for our needs, it would require some form of "coating" that would probably be as time consuming and as expensive as options that could produce superior results for us.

The key constraint is low-volume cost and local (Northern California) availability. While durability is a concern, it is not an important issue. Currently the parts are powder coated which has proven to be adequate given the use factors. Although a bright nickel/chrome appearance is desirable, anything that has a "stainless steel-like" appearance or brighter, is fine. Resistance to common cleaning agents, especially citrus-type cleaners is/would be beneficial.

Thank you for any information and advice.

Rob Howard
- Mill Valley, California, USA

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The cost sensitivity parameter is an issue; otherwise electroless nickel sounds perfect. There are electroless nickel plating processes specifically made for magnesium. Atotech's MagENta is one.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006