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In what concentration (gram/liter) would I need to dissolve the granules to get a good result?
Since I have a local anodising shop, for whom stripping existing anodising before refinishing is a normal line of business, I've never even contemplated how to do it at home 🙂
Internet opinion is that it can be done with NaOH but that's not how pros do it because NaOH actually dissolves the metal better than it does the eloxiert coating. The professional method involves hexavalent chromium, which we've already been warned about once today, so you definitely don't want to try that at home.
Brief (30s-1min) immersion in a 10% (100g NaOH per litre) solution is suggested as a successful recipe. Bear in mind that this is a very caustic solution (pH>13) which will also strip flesh, so be careful. Keep a lot of plain water on hand to rinse both the cycle parts and any rapidly disappearing body parts.
I'd worry slightly about the steel/aluminium interface as it will be difficult to clean properly to stop the reaction. The GXP axle is only pressed into the driveside crank, so it's probably going to suck your caustic solution into the gaps by capillary action. If you do decide to proceed, think about how you're going to prevent that with some sort of compatible sealant, from both sides.
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gbj_tester
@Rodolfo
One for @gbj_tester I presume..
I want to deanodize some aluminium Rival Cranks (gxp this time, so steel axle) and bought some "rohrreiniger" which lists the needed natriumhydroxide as almost sole ingredient.
In what concentration (gram/liter) would I need to dissolve the granules to get a good result?
Many thanks!
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