How to clean BLACK aluminum,

[DreyeIce]

i have a cylinder jug here that one side is OK to clean and polish, and the other has bad white chalky buildup and the metal is dark underneath, its like it was laying half-in half-out of a chemichal bath,

anyways, what can i do a dip in to get that aluminum back to its natural color and not almost black, thanks,

[JCPakBikes]

It sounds like a anodized surface that is oxidizing?
Try Silicone spray. This can help a little.
Other wise you can use a very fine grade sand paper or the green 3m pot scrubber followed by silicone spray.
Other then that I think you may want to have it reanodized

JC

Originally Posted by DreyeIce

i have a cylinder jug here that one side is OK to clean and polish, and the other has bad white chalky buildup and the metal is dark underneath, its like it was laying half-in half-out of a chemichal bath,

anyways, what can i do a dip in to get that aluminum back to its natural color and not almost black, thanks,

[DreyeIce]

its not anodized, its an engine head, i think a very basic chemical spilled on it and it actually turned a very dark grey with lots of white chalky buildup, how do i get it back to nice aluminum?.. with an acid?

[WindyDucat]

Originally Posted by DreyeIce

its not anodized, its an engine head, i think a very basic chemical spilled on it and it actually turned a very dark grey with lots of white chalky buildup, how do i get it back to nice aluminum?.. with an acid?

I am restoring a 73 Ducati and started down the acid path and quickly found out it can make things worse. If you are using acid I would stick with the "lighter" ones like oxalic.

I would stay away from acid and stick with mechanical. Specifically soda, or sand blasting and then a buffing wheel to bring it back to life. Especially if you suspect the aluminum it is pitted or scared underneath the buildup, the acid may make the surface worse, where as blasting and buffing will remove only the material you want, layer by layer.
Cheers! Windy

[uglyducky]

Originally Posted by WindyDucat

I am restoring a 73 Ducati and started down the acid path and quickly found out it can make things worse. If you are using acid I would stick with the "lighter" ones like oxalic.

I would stay away from acid and stick with mechanical. Specifically soda, or sand blasting and then a buffing wheel to bring it back to life. Especially if you suspect the aluminum it is pitted or scared underneath the buildup, the acid may make the surface worse, where as blasting and buffing will remove only the material you want, layer by layer.
Cheers! Windy

ya, sounds like the cleaner is too harsh

[WindyDucat]

Drey, if you want to try an acid cleaner, I suggest you get an aluminum wheel brightener from an auto store. Start with something proven and low risk to your parts. Nitric and Muriatic work with Aluminum but are very caustic and used improperly can do great harm...if I were using them I would go to a refinisher who specializes. Also "aluminum" is usually in alloy form so it is good to know what other metals you are working with. If you use acids, start very diluted and test is a very small area.

[DreyeIce]

the top and bottom are easy to clean mechanically, but between the fins is very hard, and ideas how to go about that?

[WindyDucat]

I have not used these, but they are suppose to work well.

Small Brushes to clean, detail and refinish cast aluminium alloy motor surfaces, restore aluminum alloy motorcycle engine and auto motor castings, engine crankcase, cylinder head. To restore motorcycle aluminum alloy, and safely remove corrosion. Fou

I as at Northern Tool this weekend and they had similar brushes much cheaper. 000 or 0000 steel wool works, tedious but does a great job. As someone suggested one of the 3m pads would wor - they come in several abrasive levels, get the right ones