Getting nics out of aluminum

[akdube]

When I bought my boat it had some good nics and scratchs in the hull on the front sides from being tied to tight to a dock in some bad weather by the looks of it. There are some that have a sharp ridges on them. What would be the best way to to "dress" them up...or out if possible? There not terriblly deep but is some what of an eye sore. Thanks

[Music Man]

4" angle grinder with 80 grit flapper disc.

[akdube]

4" angle grinder with 80 grit flapper disc.

Will this put swrils in the metal? Id like to clean it up as I would like to get it looking good again.

[ironartist]

I clean up aluminum with a dual action air sander, it will put a nice cross hatch looking pattern

[JOAT]

Forget sandpaper or flappers! You want to use a wire wheel on a 4" grinder. A medium wire will round off all the sharp spots. A fine wire will smooth out the surface and allow you to feather in the finish.

[Garyak]

When I bought my boat it had some good nics and scratchs in the hull on the front sides from being tied to tight to a dock in some bad weather by the looks of it. There are some that have a sharp ridges on them. What would be the best way to to "dress" them up...or out if possible? There not terriblly deep but is some what of an eye sore. Thanks

Is it painted? I've experimented a bunch with jb weld. Maybe you could carefully sand any jagged edges close to flush then fill with jb. After it cures, sand it all down flush and then touch up with some aluminum or whatever color paint. JB is tenacious stuff..and inexpensive. I'd rather fill a gouge than remove material and risk ending up with a "dish" in my finish that could be even more of an eyesore. I might just be paranoid...but I hate the idea of removing "structure". GLTY!

[Paul H]

Forget sandpaper or flappers! You want to use a wire wheel on a 4" grinder. A medium wire will round off all the sharp spots. A fine wire will smooth out the surface and allow you to feather in the finish.

I'd be cautious using a wire wheel. Wire wheels leave a bit of themselves in the material you use them on, and with aluminum being a less noble metal, it will corrode first due to galvonic action.

I'd go with an abrasive wheel on a grinder, I've found the 8" autobody attachments work wonders with 80 grit. For larger dings I'd likely first hit them with a file.

[ironartist]

I'd be cautious using a wire wheel. Wire wheels leave a bit of themselves in the material you use them on, and with aluminum being a less noble metal, it will corrode first due to galvonic action.

I'd go with an abrasive wheel on a grinder, I've found the 8" autobody attachments work wonders with 80 grit. For larger dings I'd likely first hit them with a file.

if you are going to use a wire wheel make sure it's stainless and not a carbon steel one. I seen in at weld air one day they had some kinda fancy wheel for polishing with a small angle grinder aluminum but I have never needed one
I would still suggest a dual action and some 80 grit in my professional opinion

[OzAK]

I use Scotchbrite discs in different grits depending on how bad/deep the damage is. They will leave swirl marks only if you allow them to with your technique. Decrease your grit size as you get rid of the damage, the strength of the parent material won't be decreased enough to ever know. Final polish will be by hand with Scotchbrite pads in the direction of the grain of the metal. You won't be able to tell they were there unless you knew it beforehand. Discs are grit sized by color, coarse to fine, brown, purple, blue, grey. Brown is very agressive, grey will polish and do little else. Hand pads you will need are purple first, then gray. Should get the job done nicely. I use this stuff on aircraft sheetmetal and welding projects every day with great results. Good luck. Oz