I have an aluminium plaque that I need to clear the oxidation

>>1048131
Sandblast it

>>1048134
We don't have easy access to one. Is there any other method?

>>1048131
Citric acid will, but it will take a long, long soak in anything other than concentrated citric. MEK will also clear it, but it may fuck up your piece too, so I wouldn't use that.

>>1048145
Thanks. Would this be for the oxide, the paint, or both?

Just found this:
http://www.ebay.co.uk/itm/Citric-Acid-250g-25Kg-Food-Grade-Bath-Bombs-Home-Brew-/400395458753?var=&hash=item5d396dd8c1:m:mM-w4AkXikGcAdIVAD36sNQ

Do you know if it'd be suitable after adding water?

>>1048131
if it's not to big then you can dump it in a tub of stripper and then brass brush it the next day, I once had a motorcycle engine part vapour blasted (don't ask me what they used I just followed their suggestion) by a guy and it came back shiny as fuck and looked like brand new, it cost me £20 ($30) and was worth every penny.

>>1048148
The oxide. Without knowing what kind of material for the paint, I can't answer. It's very possible the citric would work.

Food grade citric should be good enough. I'd mix it 1 to 2 (eg, 1 gram into 2ml water.)

>>1048159
Thanks. We suspect, but don't know for sure, that it's this:
http://www.hammerite.co.uk/product/direct-to-rust-metal-paint-hammered-finish/

It's at least something similar.

>>1048152
That's interesting info, thanks. If all else fails we'll see if we can get that done.

In other news, we just removed the paint stripper after applying two coats, and it's working!

>>1048131

Does it fit in the oven? If so, oven cleaning cycle.

>>1048159

> Food grade citric should be good enough. I'd mix it 1 to 2 (eg, 1 gram into 2ml water.)

Wear goggles and gloves, do it in a ventilated area.

Vinegar is also a week acid like citrus. I use it to dissolve rust on vintage bmx frames- but since its used in things like making pickles its virtually harmless to humans. You need ventilation though, the fumes (although not toxic) can be a little much.
Check often if you use any acid solution- leave a nail in a bottle of coke for 6 months and it will dissolve completely.

>>1048131
Why'd you wanna go and do that to the oxide? Aluminum is great BECAUSE it has that oxide layer, besides taking it off doesn't really mean anything because it reforms instantly in air.

For the paint try ultrasonic and acetone

>>1048221
The oxide has formed clumps, I don't mind a thin tarnish but it will affect the smoothness when I repaint it.

>>1048225
Nigga, aluminum don't form clumps. Oxide layer is so fucking thin man it doesn't matter.

>>1048225
aluminum oxide layer >>1048602 doesn't clump. it's on the scale of a couple nanometers, so it is actually almost perfectly invisible to the naked eye unless it is the unnecessarly thickest anodization ever.

>>1048602
>>1048630
What's the white powdery stuff then and how do i remove it?

Caustic soda ( sodium hydroxide) Will remove the oxide from aluminium. It will also etch it if you use it too strong so go gently to preserve the detail. It is worth anodising it once you are done to reform a nice oxide layer, which will make it less likely to corrode 7n the future

Use Lye solution (couple of tablespoons to a gallon of water) to clean/etch the aluminum. The clumps are an oxide that can be removed with an application of hydrochloric acid. (Lysol toilet cleaner). Let each solution sit for a few mins and rinse before using the next. Repeat until the surface is bright and clean.

Well I am sure