Black anodizing repair

I wanted to improve the appearance of the black anodized frame and mast on my '86 HC16.

I read the forums and used Penetrol as recommended in this thread. Penetrol worked relatively well on the slightly faded anodized aluminum but, of course, didn't do anything for scratches and areas where the anodizing has worn off.

I investigated the anodizing process and about repairing it. First, anodizing is slightly different from the plating process, but similar. Anodizing actually builds a new surface of aluminum oxide made up of microscopic tubes.


The coloration (black, blue, purple, etc., etc.) actually comes from dye that is added to and fills the tubes, and is then sealed, usually with a chemical process. That is why anodizing can fade.

I didn't research far enough to find out if you can remove the clear sealer and dye without completely removing the oxide, then re-dye the aluminum but suspect it may not be possible. You can buy do-it-yourself anodizing kits from Caswell, Inc.. They have all kinds of info on their web site, and also carry some automotive paints that might work with small repairs. Anodizing requires a power source (battery charger), some chemicals (battery acid), and other misc stuff.

It is likely impossible, or nearly so, however, to do spot repairs since the process is really designed for the parts to be immersed in the acid solution.

Just thought some of you might want to know.