Metal finishing Q&As since 1989

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Wet sanding aluminum motorcycle

2004

I have a aluminum Honda CR250 and I was told to wet sand it with 1000 grit sandpaper. However when I did that it scratched the aluminum. I've tried polishing it but the scratches are very evident and quite blotchy. My question is what do I need to do to get the scratches out? Thanks for your input.

Steve Payne
motorcycle repair - Mapleville, Rhode Island, USA

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Could you tell us what parts you were trying to sand? Why did they need sanding? 1000 grit is typically pretty mild stuff, were you using water to keep it wet?

What did you use to polish it with afterwards? Chemical polishes like Mothers Mag & Aluminum Polish and others will not get rid of scratches. They are meant to remove oxidation and road-film.

Using buffing wheels and brown tripoli rouge (polishing/buffing compound) [affil links] will remove sanding scratches from plain aluminum. If you have clear coats or anodizing on the parts, that will have to be removed, but I have seen anodizing get removed with aggressive polishing. You will have to polish the entire part to get an even finish. Of course, the protective anodize coat is now gone as well!

Ray Coogan
- Lake Havasu City, Arizona, USA
2004

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I am sanding a aluminum motorcycle frame. I am trying to restore it. I've wet sanded it with 400, 600, 1000 grit paper. I've used a buffing wheel on a drill with red jeweler's rouge (polishing/buffing compound) [affil links] compound but still have spider scratches that make it appear cloudy. I've polished it and it's shiny but still has many scratches. Can anyone tell me what type of polishing wheel to use and what I should use to take the scratches out. Any advice would be greatly appreciated. Thank you

Steve Payne
- Mapleville, Rhode Island, USA
2005

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Hi, Ray. letters 800, 1831, and 10917 go into substantial detail about aluminum polishing. Good luck!

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 29, 2008