REF: Suspension - Sub-02C
Front Forks - Refinishing Aluminum Sliders
This information comes from an XLForum thread: https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/203388-slider-repair?t=2080639
Some editing done on the comments. Photos are by 'joe s'.
Comments by joe s - Describing his finishing process
If the pits aren't too too bad, you can sand them and re-clear. On my FXR project, I disassembled the forks, but I don't see why you can't do this on the bike with the wheel and fender removed.
This is what they looked like:
I cleaned everything with acetone first, and that started removing the factory clear coat. Perfect, because it left the original finishes that I can match after repairing the scratch marks and oxidation spots. I dressed them with a dremel on slow speed. Letting the stone bounce at the very end, sort of reproduced the surface, but not well.
They look like they have a skin condition.
Looking at the factory shiny areas, there are fine sanding marks, so first I tried 400 grit, and that removed the stains, but was too coarse. 600 grit was closer, but 1000 grit was just right.
You can see what I mean by rough and smooth areas.
Make sure they are really clean again, wiping with acetone until the rag is clean. I use NAPA Tec Base clear in a rattle can, it holds up well and stayed clear on my 79 FXS for years, including the rocker covers:
Good luck, your mileage may vary.
Comments by SHAKY DAVE
Absolutely nice work. Since I do the paint and body work on restoration cars, step sanding is the way to go. I sand aluminum starting with 600 going up from there with 1000,1500,2000,3000 to 5000. Pretty shiny then, but I normally buff the parts and dont use any clear on anything. The buffed parts on my 2 ironheads are still great after 11 years. Some Mother's aluminum polish takes care of keeping parts lookin good, but only when i feel like doin it - hahaha.
Comments by brucstoudt
I had the same problem with my '03. It was caused by salt air corrosion from being in Florida. Most of the damage was in the front area in the windstream. I fixed mine on the bike by wet sanding them with 1500 wet or dry paper then polishing them. I have a brick of aluminum polishing compound that I load on my polishing buff. The sliders come from the factory with a clear coating on them that has to be sanded through to get down to the aluminum. I will not reclear them.