I want to polish up an aluminum valve cover on the Murdercycle. It's that typical oxidized aluminum look that you'd expect to see on 37 year old aluminum. (No salt corrosion, I'm not that hard core of a rider.)
I want to try to polish it up. I've got two 2" cloth wheels, one with cutting compound in it, and the other with polishing compound on it. I have a Dremel tool for tighter areas.
And magic juice that will cut the oxidization so I can start polishing sooner? Or and technique to speed things along? I'm not a Harely guy, so I don't know crap about polishing.
You didn't mention what make or model the motorcycle is, but most of them have some sort of coating on the aluminum covers, whether it's lacquer or something else. That finish eventually breaks down and is what generally causes the scabby finish. You have to remove that coating first, before trying to polish the aluminum. As for polish, I like Simichrome but it can be hard to find, Flitz is another good brand.
1980 Honda CM200T TwinStar. Anything to remove the coating? or just elbow grease?
Cover looks like this:
If there is a coating, I've used aircraft stripper. For polishing that type of alum I use a brass wire wheel on a drill. (Tape the trigger down or your wrist will be killing you afterwards, or at least mine did after four wheels...)
Yeah, paint stripper for the clear coat on Harley parts. That cover in your pic has no clear coat on it, so nothing to worry about there.
Mother's Aluminum Polish. Start with that. A jar goes a long ways. Or if it is off already, just start with a buffing wheel and some red rouge.
I figured you were talking about side covers that were originally polished - that valve cover appears to have always been unpolished rough cast aluminum. NAPA and other places sells an aluminum brightener in a spray bottle that works well to clean up cast parts like that. It's harsh stuff (hydrofluoric acid) so definitely wear the proper protection when using.
I've had very good results doing the following.
Aircraft remove
Sanding with say, 220, then 400
Cloth wheel on bench grinder, and/or drill with varying grits of rouge (wheel, and rouge available at box hardware stores)
I hate to contradict anyone, but I would recommend caution with the use of wire wheels. If you must, go with brass, rather than the knotted wheels you put on an angle grinder.
Get some A/C coil cleaner NU-Brite spray, let foam, scrub and rinse. It will foam and lift a lot of crud off and make the going easier to start by breaking up the oxide layer.
Others like OSPHO but nu-brite works best for my and its great on diamond plate when diluted per the directions.
Nu-Brite
