Polishing motorcycle frame

[btorres09]

I am polishing a motorcycle frame and for some reason can not get the cast aluminum part to shine as bright as the non casted aluminum....i sanded from 220 to 1000 and started with the tripoli on a sewen wheel then used white with a loose wheel.....does anyone have any suggestions....thanks in advance... Should i use emery first then tripoli then white and how long should i use each compound for....

[jrow]

Originally Posted by btorres09

I am polishing a motorcycle frame and for some reason can not get the cast aluminum part to shine as bright as the non casted aluminum....i sanded from 220 to 1000 and started with the tripoli on a sewen wheel then used white with a loose wheel.....does anyone have any suggestions....thanks in advance... Should i use emery first then tripoli then white and how long should i use each compound for....

Yes start with Emory on a sewn wheel then progress from there. Try wet sanding with 600 grit then polishing. IMO there's no reason to go above 600 grit before you start polishing! You may need to use a Sisal or Airway wheel depending on the condition / grade of your aluminum. How are you going to keep the aluminum frame bright and shinny after you polish it?

Good luck.

John

[Rasper]

Different alloys of aluminum have different colors, and different shine qualities. I like 1100 Aluminum the best; it's almost pure aluminum, (at least 99 percent); and it is the brightest. But it's not very strong. The other elements that are alloyed with aluminum, such as copper, magnesium, nickel, tin, zinc, silicon, affect the color and the shine. The best casting aluminum, (eg. transmission cases) in my experience, is not the best polishing aluminum. In general it has more alloys than sheet aluminum.

I have a backyard foundry and usually use beer cans for casting things that I want to shine the best. They are pure aluminum with negligible alloys. But of course you have to polish what you have, not what you like.

Richard