Plating of Aluminum Honeycomb Panels for Telescope

Q. Could anyone identify a process, supplier etc. To allow precision re-coating of some panels. They belong to a telescope in Hawaii. The panels are precision formed from thin gauge Al, on a honeycomb backing. Some of them have warped away from spec, and I wonder if it possible to deposit Aluminum on the surface (i.e., in selected areas determined by CMM in thicknesses of 2-25 microns). The panels should not get too hot in the process! (guess, 50-80 °C max). Each panel is approximately 2' x 3' in size. I would welcome any suggestions.

A. Hello, Ian.

Five theoretical ways to deposit aluminum include electroplating from an aqueous/organic electrolyte, electroplating from molten salt, vacuum metallizing, Ivadizing, and aluminizing. It seems to me that only the first method would keep the temperature in your range. Electroplating of aluminum is special because aluminum is more active than the hydrogen in water, so the electrolyte is organic, and air must be excluded from the process. I only know of one shop (Alumiplate in Coon Rapids, MN) that does it. Maybe someone can offer encouragement with a sixth process or through reassurance that one of the already named processes won't generate unacceptable heat. Sorry for any possible discouragement, and good luck with it.

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