It's basically the same as yours. As I recall, it might be 31%, near enough to not really matter. I believe it does not contain HCL. The problem with HCL in etching solutions is it's prone to after-rusting relativly fast. But, it is one of the two acids in Aqua Regia type rusting solutions.

Regards
Ken

Last edited by Ken61; 01/02/17 09:38 PM.
I prefer wood to plastic, leather to nylon, waxed cotton to Gore-Tex, and split bamboo to graphite.