Polishing Aluminum crankcase covers...

[Anonymous]

...having a heck of a time getting these stupid things looking any good. They're cloudy, and have odd little "spots" all over them...slightly discolored from the rest of the aluminum. I've tried polishing them to a shine, but while it IS a bit better than it was, still looks rather cloudy, and can still see those stupid spots.

Any tips on a better way for me to polish the aluminum?

On a small part of one of the covers, I took my Dremel and put on the small steel brush, and that IMMEDIATELY "shined" it up, but then ended up leaving dark streaks along with the shinier aluminum.

Any clue what to do? Thanks guys!

 

[shaftzuki]

Sounds like you haven't stripped the old clear coat off yet ... 8)

 

[Anonymous]

It sounds like the spots are oxidized aluminum, which is EXTREMELY hard. It's so hard that they usually make sandpaper out of it. Has this bike been wet long, say over a winter?

If you do have serious patches of oxidation, I'd say the best bet is to go at it with some really harsh sandpaper (#120 or less) and take it down that way. Then come back with lighter sandpaper and shine it up again.

I don't recommend using any kind of wire brush on the aluminum because little flecks of the brass or steel brush will remain in the surface of the aluminum and cause more trouble later. Others here on the forum don't think it's a problem, though, so consider all advice "use at your own risk."

Good luck,

Michael

 

[Anonymous]

I have used two techniques both are very good. First you need to get the clear coat removed. As stated earlier you can use sand paper starting with #120 or higher and then go higher #200 THEN #320 and so on. Then you need to polish I use "Autosol" but "Mothers" works well. You can also use steel wool found at any building supply store it comes in three different grades fine, medium and coarse. Again start with coarseand work to fine and again polish once the clear coat and pitting has been removed. Its allot of elbow grease but the results are well worth it. Andy

 

[dig dug mx6]

i just did mine. first I hand sanded off all the clear coat then did a 400 600 the 1500 wet sand.. Then I hooked up the polisher on the drill and kept working till it was mirror like then a little mothers aluminum polish and they look better than new.

 

[Anonymous]

Got it. Didn't even think of there being a clear coat on there.

Thanks for the advice guys...I'll give it a shot.

 

[back_online]

NOW YOU TELL ME, I JUST ORDERED NEW COVERS to get rid of all that oxidation. lol. :wink:

i just did mine. first I hand sanded off all the clear coat then did a 400 600 the 1500 wet sand.. Then I hooked up the polisher on the drill and kept working till it was mirror like then a little mothers aluminum polish and they look better than new.

 

[92G]

A little late, but I spent some time working on mine and they aren't bad. Not perfect, but a world better than when I started...

I took a paper towl with acetone accros the clear coat, then used a heavy steel wool to rough the paint up, and then back with the acetone, and it comes off pretty quick.

I then used "lightly/carefully" used a heavy 100 grit sand paper for the places that had really heavy oxidation, emory cloth to smooth it out, and then Bom's Away Polics, which is awsome, for the final shine.

The Bom's Away also seals the metal and protects it. You can actually see water bead up on it like a waxed painted surface.

Terry

 

[Can_O_Tuna]

I did the sandpaper thing starting with 120 all the way up to 1500

Put a couple of tablespoons of Mother's in a 1/2 bottle of dish detergent and use that as well as water as a sanding medium (shake well) > then get the buffing wheels out .

http://www.caswellplating.com/buffs/buffman.htm

 

[Jay B]

An oldie but a goodie.

http://www.thegsresources.com/_forum/viewtopic.php?t=8508&highlight=polishing+aluminum

http://www.thegsresources.com/_forum/viewtopic.php?t=48&highlight=polishing+aluminum