I’ve seen this done with vinegar and sodium hydroxide. I’ve discovered a degreaser that can get rid of anodizing without tarnishing aluminum.
I can’t comment to the outcomes of doing this because I haven’t left components in the solution overnight previously.
What is a good anodizing remover?
You’ve probably seen our top choice on the anodized aluminum remover list if you’ve read any bike forums or other forum discussions about removing anodized coating. In reality, half of the items on our list may be found in standard household cleaning products like drain cleansers and oven cleaners. However, as we previously stated, just submerging them or spraying solutions on aluminum components frequently is ineffective. You must perform this task in a controlled setting; nevertheless, we shall discuss safety measures afterwards.
- The most popular technique for removing anodized coatings is sodium hydroxide, often known as caustic soda or lye (NaOH). Caustic soda typically has a concentration of 2-10% of 50% liquid caustic soda by volume in water. The anodic coating should come off in a matter of seconds to minutes, depending on the bath concentration and temperature.
- Caustic potash (KOH), also known as potassium hydroxide, is a strong basic (alkali) that interacts favorably with acids. It frequently coexists with sulfuric acid and sodium hydroxide in drain cleaners. This caustic etch solution will probably produce a matte appearance on the component when used together.
- AcidEtching: This procedure uses a solution of phosphoric acid and chromic acid (CrO3) (H3PO4). As this chromic phosphoric acid solution has been shown to have no adverse effects on the aluminum surfaces or lead to more pitting, the final product will likely resemble how it did before the aluminum was anodized.
- Deoxidizing: You can also use a potent de-oxidizer to strip the aluminum surface. De-anodizing would include eliminating this top layer of finishing because the anodized coating on metal is essentially a thick oxide layer. Here is one method for removing a knife’s anodic finish. It is also a useful manual for removing anodised color from aluminum.
How is hard anodized aluminum removed?
The anodizer is correct in theory. You might not, however, be happy with the outcome. The sodium hydroxide-based standard etchant or a “non-etch stripper” can be used by the anodizer. Even if the coating is completely removed uniformly, the anodised area (on the surface that wasn’t supposed to be anodized) may still be slightly rough and may not be perfectly level with the surrounding non-anodized surface. This is so that the anodic coating, which actually penetrates the aluminum, may form. A portion of the coating permeates while a portion accumulates. From 1/3 penetration and 2/3 buildup to half and half, the ratio of penetration to buildup varies. Therefore, if the coating thickness is two mils, the area that had anodic coating may be approximately one mil or more “smaller (or deeper)” than the area that did not have anodic coating after the coating has been stripped off. However, during stripping, the substrate beneath the anodic coating will begin to etch before the unanodized area. Who knows how the surfaces will seem once the entire old coating has been removed.
The Type III coating can occasionally be stripped unevenly, especially if it has been sealed. On the portion where some of the coating is still there after other portions have been totally peeled, this causes blotchy regions. As a result, whether the surfaces are covered in masking tape or not, they may have an uneven surface. If this occurs, the surface cannot be made level and smooth without resurfacing with a cutting or grinding tool. You have an issue if cutting or grinding that surface will cause it to be outside of dimensional tolerance.
When removing all heavy anodic coatings, it’s a good idea to soak the components or loads for up to 45 minutes in a strong acid bath, such as the deoxidizer or even the anodize bath, rinse, and then remove the coating. If the parts have been sealed, this technique will break the seal and soften the coating, making it much simpler to remove entirely and uniformly.
The anodic coating can be removed off the pieces using a “non-etch stripper” without removing any of the substrate metal. However, if any anodic coating has seeped through the masking, the surface may still be uneven. This is as a result of the coating there penetrating.
Non-etch strippers frequently employ zinccate-based products. A chemical substance known as a non-etch stripper will remove the anodic coating (aluminum oxide) but not the aluminum metal itself. A second effective non-etch remover combines phosphoric acid and chromic acid. I’m aware that this solution is no longer utilized because it includes hexavalent chromium.
Can anodizing be removed by bleach?
Most anodize will be damaged by using bleach straight from the container. Any caustic substance, such as diluted drain cleaner (lye) or ammonia, should get you there if that doesn’t work.
Can anodizing be removed by acetone?
Unexpectedly, anodizing has a high level of resistance to organic solvents. While acetone or alcohol will swiftly remove the ink from a permanent marker, they won’t harm or deteriorate colored anodizing and are therefore useful for cleaning.