polishing enclosures

[Cozybuilder]

This is one of those situations where you are better off paying the little extra for a quality casting to obtain a polished aluminum look; I'd start with a higher grade material, such as a box from Hammond. IMHO its just not worth it to etch a cheap box, the price difference isn't worth your additional effort to salvage the box when pits in the inferior casting show up from the etching process. Side by side, a quality cast box is obvious. If the box you get is grainy, paint it.

For cheap boxes (such as Tayda and E-Bay bargains) I just flatten them with sandpaper on a hardwood block, usually starting with 150 grit, work up to 220, prime, sand with 320 grit, paint, 400 grit, clear coat, apply graphics, light coats of clear with light sanding between to flatten the painted surface using 400, final coat with clear. The box gets placed in a hotbox after each coat of spray- lightbulb to heat it. Works for me.

[GGBB]

Who's assuming? They are aluminum die cast boxes, per Tayda. I understand alloying additives, but those should be fairly homogeneous close to a molecular level. Most likely, what I'm encountering is just particulate debris that made its way into the mold. It happens in cheap castings.

Isn't this how China gets rid of toxic waste?