Not sure if "you guys" is proper English or not, maybe I should have said you'uns or youall: y'alls.

Anyway, I put some vinegar on it and it kinda looked at me, with that "what are you stupid" look, so then I used some muratic acid, like they use in pools. It started smoking and making bad smells . I got the "what are you really stupid" look as I coughed off outside, and I thought maybe I should go inside and ask the folks with the nice looking engine bays what to do.

There’s magnesium in the housing. It will react to hydrochloric acid by turning the metal into hydrogen gas. No bueno.

I like to have the housings soda blasted. Then you can decide whether to coat it. There’s a rattle can paint called “alumi-blast” which I think looks good. But you have to make sure everything is super clean.

Good luck and, as they said at Woodstock, stay away from the acid, man…

Read the "1.8 cheap junk rebuild" thread over on the Type4Forum or the 411/412 forum on the Samba.com for cleaning do's and don'ts.

Glass bead blast and a good coat of 2K clearcoat makes aluminum look good and stay looking good.

Keep acids / caustic cleaners away from aluminum and magnesium

Thanks guys. super helpful

Aluma Blast is an Eastwood paint product.

https://www.eastwood.com/search/?q=aluma%20blast

this looks like a good idea, since i've tainted it in spots with the pool acid.

I had mine media-blasted, and then I painted the sections with a matte epoxy clear coat. It darkened the color just a bit.

Im working one one right now....
After media blasting it showed all sorts of voids, holes sort of like it had been rotting?
Ive done a few of them & this is a first for me.
Looks like Ill need to fill it with allmetal & sand to get it back to acceptable.