How To Clean Corroded Aluminum?

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zghorner

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Just bought s 2001 KX250 dirt bike from my bro in law. The thing has sat in a shed for years and not everything that is aluminum has a white corrosion on it. I was thinking maybe some CLR and scotch-brite pads but really have no clue. any ideas?
 

swampratt

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soap and water and scotchbrite.
They make a light duty white one . depending on how bad it is as to what grit you know that though.
The clr and other aluminum spray cleaners are acid and etch the aluminum and your aluminum is probably already pitted or etched.
I would avoid that stuff and if you do use it rinse and clean it off well or it will continue the process.

Oil and scotchbright do well also like a 3M oil or light machine oil.
 

NightShade

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I used the Brillo pads on some aluminium when I was a kid. Sounds counter intuitive I know but it took a dull piece of a skin on a garage door and polished it right up, just a new pad with the embedded soap and water would bead on the surface. If I was to do something like that now I would go down and get some 0000 steel wool and some oil or polish and do it that way on something that wasn't smooth and polished in the first place.
 

NightShade

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If you let the steel wool sit and oxidize yes then it could potentially create thermite. If you add a very hot heat source so scrubbing with the steel wool dry and then letting it sit somewhere for an extended period of time till it rusts maybe something could potentially happen. Then again you can speed up a reaction by touching a 9v battery to a piece of steel wool on it's own, while not as impressive as thermite it has likely started more house fires.

Galvanic corrosion is also possible but again requires extended periods of contact over months if not years.
 

zghorner

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what about using a chore boy (copper) instead of steel wool? Definitely going to pick up some scotch brite pads and I have been reading of people wadding up some heavy duty aluminum foil to use as a scrubber with good results.
 

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I'm not sure what they use but the big truck washes can make an old nasty horse trailer or cattle pot look brand new.

Generally they power wash and either use a two step process which is a standard soap following an alkaline soap (think like oven cleaner that is very diluted) or for aluminum that is a bright white it's an acid wash. Worked at a truck wash for two years when I was in high school.

That is actually where I learned about the ability to use a brillo pad to polish aluminum. We used them to clean the crud off of chrome. We were really slow one day and I picked on up and hit a piece of old nasty aluminum on one of our roll up doors and it turned bright and polished with a minimal amount of work. After everyone else saw it the trick was used a couple times when some jerk would insist on having a trailer acidized but would refuse to drop the trailer and have polished tanks and wheels. Even if we tarped the tanks and wheels there were times when a little acid would end up on the tank and remove the polish. Hit it real quick with a brillo pad and send it on it's way. Never once had a fuel tank burst in to flames either so the risk of creating thermite is pretty low.

I think part of the reason why the steel wool works as a polish is it is able to work the surface smooth and the 0000 is so fine it does not scratch it up badly. When you use a polishing compound you are effectively manually machining it smooth as the compound will have a grit to it albeit very fine. A chore boy that is REALLY coarse may end up causing more problems than good. Foil crumpled up is basically the same thing but since it is softer than the aluminum surface you are working it does ok. If I was going for a show piece I would hit it with the steel wool and then follow up with a polishing compound but to just get it presentable and remove the oxidation the 0000 wool would work fine. If you search online you can see where other people have done it. The only complaint is that if you work it too hard it can potentially leave fine pieces behind but I also believe that is due to using something too coarse and dry. If the wool is encapsulated in oil the potential is minimal and a true polish or sanding (2000 to 3000 grit) and then polish would eliminated that anyway.

If you wanted to forgo the steel you could use progressively finer sand paper to polish it as well. Just make sure that you back with a foam block so that you can make it conform to the surfaces. By the time you get up to 2000 grit it will be like a mirror. You can take it even farther if you want a quick search will show some people going all the way up to 7000 grit wet sanding. If I remember right some of the places that make large aquariums using acrylic use a similar process when they need to bong multiple pieces together and make them optically clear.
 

skyhawk1

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If you use anything abrasive it will take the factory coating off (protects from corrosion) You already have lost a lot so probably not a big deal. Afterwards you will have to coat with a finish or polish frequently.
 

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