[xtal01]

Exactly what I wanted to know.

Although a mechanical engineer by trade (never taught us much about hands on work ... like how to anodize), I have a small shop (mill, lath, ...).

I am very much a "do it yourself" person (always building something ... wife says at least she can find me in the shop and not out drinking with the boys).

It does look like a type II process would be fine for my AR-15 lower (and a few other small projects I am working on ... front of a pulse jet engine for one).

Just for my own curiosity, what is the correct temperature for type III anodizing?

I see your point with dry ice as a coolant. I did however build a a/c unit from scrap parts twice int he past, I suppose this would be what I need.

Thanks .... Mike