Thread: removing anodising

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http://www.clubhotrod.com/forums/sho...nodizing...yes it seems correct spelling does do wonders .. just click on the search button ( rite under the private message notice ) and type in " how to remove anodize " and i got three dif threads to pop up

As I recall, anodizing is done by running current through the piece in a basic (pH approx 10 or more) solution and adding a dye to the solution. This forms a surface of aluminum oxide which traps the dye in the oxide and a lot of colors can be used or not. Aluminum will dissolve in either acid or basic solutions but the anodized surface is an oxide which would normally dissolve in acid. I have not tried this but if you use any acid it should be a mild acid and I would try buffing with a cloth buffer dipped in white vinegar which is a dilute form of acetic acid and is mild enough to not dissolve clothes or other metals near the splash/spray. Muriatic acid (HCl) would be too strong and would make holes in your clothing, not to mention the need for eye protection! I did work at a plant that did anodizing but it was the finished surface and we did not try to remove it. As I said I have not tried this but powdered aluminum oxide (alumina) is a form of abrasive itself so the combination of mild acid and surface buffing may do the trick. Let us/me know if this actually works! I offer no guarantee other than the usual chemical principle that oxides are basic and acids dissolve bases but aluminum is unusual in that it reacts easily with acids and bases (amphoteric!). Since the salt formed will be aluminum acetate and all acetates dissolve in water, cleanup is easy with water wash/wipe.

Don Shillady
Retired Scientist/teen rodder

Oven cleaner. Although I have not used it personally, there was an article in a magazine several years ago that explained how to do it. You will have to experiment with the amount of time to leave it on as I do not recall the particulars of the article.

Hey, I want to cover my rear against law suits. Check out the pH of any Oven Cleaner. I looked at three on-line and the pH of the ones I looked at ranged from 11.5 to 14.0 (the maximum possible in water!). That is enough to dissolve SKIN and when it does it "feels slippery" because it is dissolving the skin. Sooo, wear goggles and rubber gloves; maybe a rubber apron too! Don't be surprised if you have many holes in your clothes after you wash them! I have my doubts about using a strongly basic solution to remove the effects of a basic treatment. I guess I would try just soaking the parts in white vinegar and then buffing them when dry and then soaking them again, drying again and buffing again etc until the coating is gone. Maybe oven cleaner will work but it is dangerous and I am not sure it will work so use safety precautions if you use it and let us know what happens. My best guess is that oven cleaner may remove any blackening or color of the anodizing, but not the underlying dull white layer and will actually increase the white oxide coating; thin pieces may hole-through with prolonged exposure to strong base (high pH above 10).

Don Shillady
Retired Scientist/teen rodder

Check out this link: 2076. Removing anodizing from aluminum

Sounds like the Oven cleaner with time is worth trying. I probably have met Lee Branch at one time or another at a Chemists Meeting, but that Chromic acid + Phosphoric acid prep is definitely only for a lab setting and I still say use goggles and rubber gloves with the oven cleaner,

Don Shillady
Retired Scientist/teen rodder

Oven cleaner definitely works!!! Oven cleaner definitely is dangerous!!! Oven cleaner definitely will ruin your part if you dont pay attention!!!!!!

The second it removes the anodizing rinse with water. If there is some left on the part after rinsing do it again and quickly rinse again. Watch your parts carefully , alum. and body. Dont think that if you leave the oven cleaner on for a longer time it will remove all the anodizing better. It will start to eat at the alum very quickly......