mottled aluminum

[Coyote]

I started removing some of the paint with some acetone. The kick starter seal is masked off as the plan is to have the covers blasted. Now I have noticed they are in really nice shape and maybe I should just polish them out.
How do you get rid of the mottled grey spots? I rubbed on it a while with some scotch-brite. The spots got lighter but they are still there. This has always shied me away from polishing. Is there a solution to use or is it just a matter of stock removal?. I don't want to spend mega hours on these - especially producing a finish I have to take care of every other week. I do my best to de-chrome bikes as I hate to polish chrome. Bikes are for riding not shining. But I don't know. These are pretty nice if not excellent, It's those damned grey spots. Any tricks?

[tz375]

that's corrosion where moisture gets under/through the clear coat.

The usual answer is lots of sheets of Wet and Dry and hours of rubbing through the surface. I'd start with a can of paint stripper to get rid of that black paint and then hook up the bench grinder with an 8" or 10" sisal wheel with coarse abrasive (the one for stainless steel works well) and let the wheel and abrasive do the work.

You will need three wheels and several different compounds but will be done in 1-2 hours.

Professional polishers don't use wet and dry - they just use a big asses wheel and the right compounds.

[Fritz500]

I use the wet & dry method using a cork block on flattish surfaces so I take the whole area down. There is a tendency to just buff the corroded areas so you risk ending up with an even surface. I finish off by buffing with a smallish sisal wheel and a cutting compound suited to aluminium. It takes a lot of time but the finish is worth it.


Geoff

[Suzukidave]

I guess we can see why the PO painted the engine black . The spray aircraft paint stripper is the way to go and you can find it at Auto Zone . Maybe after cleaning up a spray of a more natural looking silver and clear coat for a engine your not going to have to keep polishing and polishing .

[kettle kid]

I use the wet & dry method using a cork block on flattish surfaces so I take the whole area down. There is a tendency to just buff the corroded areas so you risk ending up with an even surface. I finish off by buffing with a smallish sisal wheel and a cutting compound suited to aluminium. It takes a lot of time but the finish is worth it.

Geoff

I did a polish job on my, GT750j 4ls front wheel, and It came out ok ... I used a 8" bench grinder with, polishing wheels, of different grades... Starting with the course, working to fine, then switching to a polishing compound, to get the best finish.. Mother's polish..and my sons old T-shirt, Just waiting for for the chromer's to pull his finger out, and give me back all the linkage for the wheel, and I will be good to go.. I have a new wheel rim, and all the spokes done..
The centre hub, is a bit more difficult to access the centre, but I will get there in the end...










This is where I want to be in the end....

[Suzukidave]

I did a polish job on my, GT750j 4ls front wheel, and It came out ok ...

I would say the job you did on the front end is WAY better than just ok

[Coyote]

Maybe after cleaning up a spray of a more natural looking silver and clear coat

That may be the best idea yet Dave. Dupli-Color makes an aluminum paint that is quite nice. That's what runs down the center of the tank on RedZone. I already bought the stripper a couple if weeks ago. It's been over 100 degrees every day and I just haven't felt like messing with it. That plus the can says use between 65 and 90. It's already over 90 by the time I wake up good in the morning.