Really Fine Scratches - 1973 Aluminum

[asallwey]

I've been following the Caswell forums for a while and found some good info. Now I'm have a problem and am going nuts trying to solve it! I want to get a high shine on some 1973 motorcycle parts. I'm getting a very bright, good shine, but I've also got microscratches, from the last wheel. Four times now I've been through the wet sand phase (up to 2000 grit), black on sisial, brown on spiral, white on flannel. I then continued on with Red on canton and Green on canton, moving in a coloring motion, with light pressure. Today I tested the "last wheel" theory by buffing with Green in 1 direction, cleaning the part and buffing in the opposite direction. Sure enough the scratches change direction. As you probably know, the better something looks the more noticible minor imperfections are.

I try to load the wheel after every few strokes to make sure I've got enough compound on the wheel. Sometimes the piece will get build-up spots of compound. When I get these I clean the part -- hot water and Dawn soap, then try it again. Each compound has it's own set of buffing wheels.

I was thinking of hand polishing with Wendol to see if this will clear the parts up.

Any suggestions on solving this?

Alex

[mcaswell]

I'm confused as to why you are sanding with 2000 grit, then using much coarser compounds afterwards.

Sounds to me like this is what is causing the problem.

Are you cleaning the wheel after each compound change? Better still use one wheel for one compound.


Why are you using BLACK compound with sisal? This is VERY COARSE.
And as a final finish GREEN? It's a cuttin g compound!

Go back to basics. Use brown, then maybe blue with a canton flannel or loose wheel.

[mach1man]

There usually isn't a need to sand up to 2000 grit.I only sand up to 320 grit greaseless,then I start buffing.Also make sure that your switching directions 90 degrees between each grit and compound,so you get out marks left from the prevous compound.

Also what buffer are you using,or is it a converted bench grinder?

After I'm done sanding with 320 grit greaseless,then I use black on a spiral sewn,then white on a loose,and I get a mirror like shine.Brown(tripoli) tends to make the aluminum im working with cloudy,so I don't use it.

Mike

[asallwey]

I guess I got mixed up on the Green compound. I do have a dedicated wheel for each compound and am using a ~3420 rpm 8" buffer.

I'll go back over with White/canton this weekend. Thanks!

if i have to wet sand to 2000 grit i use white on a loose then clean it and call it a day!!!!!!!