[e015475]

Metal prep contains phosphoric acid and some degreaser and maybe a little zinc

You just abraded away the surface with sand/glass and exposed the steel to the atmosphere. Why would you contaminate it with a chemical when it is already perfectly clean from the abrasive you just shot at it? The key is to minimize the oxidation of the surface once the blasting is complete

The other problem you'll find is that the 'tooth' of the surface will make it very hard to wipe with a rag with solvent or metal prep on it (acetone, lacquer thinner, whatever) Any rag or paper you wipe across the surface will leave a trail of lint that the 'tooth' scrapped off. You'll have a mess of lint on the surface. My experience is to blow it off thoroughly with air before painting and only handle the surface with rubber gloves on and paint it with epoxy as quickly as possible.

If you're dead set to clean the metal, you'll have to sand it first to take the high 'tits' of the sandblasted profile before you can wipe it with a rag.

You might have guessed - I'm a 'tit' man myself