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Cleaning Aluminium/Magnesium Alloys

Dear All -

I'm an avid STM (shade tree mechanic) and one of my big problems is cleaning/degreasing aluminium/magnesium alloy parts. I have found that 'spirits of salts' (HCL?) actively cleans and degreases these parts. However, after this STM procedure the parts are 'blackened' and it's a real pain to clean off this black residue - currently a soft wire brush and lots of rubbing. Is there an easy (read chemical dip) way to get rid of this black residue? Or alternatively a chemical dip/mixture that cleans these parts like spirits of salts but leaves them nice and shiny?

Regards,

William R Thomson
- Johannesburg, SOUTH AFRICA

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I would switch to phosphatizing (use phosphoric acid) to avoid oxidation. Remember that you need a mild cleaner. Alternatively use a basic solution (NaOH) or ammonium base since aluminum alloys react at high or low pH levels. I would also stick with a known solvent made by a commercial supplier (ask your paint supplier!)

Kam Dianatkhah
- Dallas, Texas

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