Removing corrosion spots from anodized aluminum
I bought some anodized brake caliper arms that had been carelessly stored or maintained, so they have a few spots of corrosion on them. I could strip the anodizing and polish them entirely (either waxing, or having them re-anodized), but I'd like to try simply removing the corrosion spots first, to see how bad they look after that.
Anyone have a fool-proof method for this? Brass wool? 800 or 1000 grit wet-or-dry?
I think the only thing to do in this case is either leave it, or strip it. If you polish with sandpaper or steel wool, there will be a haze between the anodised layer and the metal beneath it.
I have polished brakes, a stem and a derailler which were all anodised. With the derailler, I stripped the anodised surface with steel wool and gave it a good polish. With the brake and the stem I polished the area with the fault, but created a hazy patch. Does not look too bad, but if you know it is there you will see it.
Hopefully someone else has a better method..
I believe you, because I remember vaguely having the same thing happen with another piece of equipment (not bike) that had a defect in the anodized surface. At least I have both caliper arms, so that if I strip and don't re-anodize, they'll match (each other). I am tempted to re-anodize, but they're Campy, and I despair of ever matching that unique satiny finish! They must have had some secret recipe.