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Old Virago cases need brightening

2003

I have an old virago with really dull cases, I have tried jeweler's rouge (polishing/buffing compound) [affil links] and a Dremel and can get it shiny from an angle.
However the cloudy appearance is still there in a full light straight on line of vision, how can I polish these to a high shine, that is chrome like without chroming?

Chas. D. McHenry
- Furlong, Pennsylvania

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You're on the right track, but you'll be looking a a HUGE project if you attack it with a Dremel. Personally I'd be inclined to remove any case covers that could be removed and work on them with a bench buffer mounted with a muslin wheel and brown tripoli rouge (polishing/buffing compound) [affil links]. If the actual top and bottom crank cases are visible on the bike and need to be polished, you can probably get to a lot of the surfaces with a 4 1/2" angle grinder [on eBay or Amazon] with a muslin buffing wheel and tripoli. Really tight areas would be the proper places to use the Dremel [on eBay or Amazon].

If I were doing this project, I'd start by removing any deep scratches with coarse sandpaper ("coarse" is a relative term here - you should use as fine a grade of paper as will remove the scratch in a reasonable amount of time) then work through progressively finer paper to about 320 grit. I'd then use Scotch-Brite or similar (I like Scotch-Brite #7447 [on eBay or Amazon], but I'm sure there are others that will work well) to do the final step before polishing. Polishing would probably be done in two steps, the first with brown tripoli rouge (polishing/buffing compound) [affil links] and the second with white rouge [affil links].

The cloudiness in the cases comes from fairly deep corrosion, and the only way to polish the cases is to remove metal to the depth of the corrosion. Once you get down far enough, though, your aluminum will shine like it's been chromed. If you can still see cloudiness where the was corrosion, you didn't go deep enough.

One other thing that can cause a cloudy appearance is failing to completely sand or polish out the marks from the previous step before proceeding to move on to the next. For example, if you sand with 180 grit paper, then with 240, then switch to 320 before you've got all the marks left by the 180 grit, you'll be spending a lot of time sanding with the 320 to get it smooth. It's wise to change directions each time you change grits so the scratches left by each grit are at right angles to those left by a previous grit, which makes it easy to judge when you've completely removed the marks from the previous grit. When you get to the polishing compound you don't have to worry so much about the direction of the scratches (the scratches left by tripoli are hard to see with the naked eye, and the ones left by white rouge [affil links] are basically invisible). With the polishing wheel, though, you want to make sure to keep it moving across the surface. Holding it in one place will result in ! bits of polishing compound embedding themselves and leaving a "comet tail" that's very difficult to get rid of.

Dave Aley
- Albuquerque, New Mexico
2003