A simple mix that works well is,
225 oz sodium hydroxide
5 oz sodium nitrate
1 gallon de ionised water. (Clean rainwater is as good )
Get this to boil at 140-145 degrees C and it will give a very good deep black.
Usual warning time . This along with all hot salts is really nasty stuff, it'll blind you instantly, cause horrible burns and will erupt if you add water too quickly.
If you take your time, take care and keep your eyes and skin covered, then it's no riskier than frying food in oil. Seriously, take care and don't get distracted.
Fresh salts can be a bit hard on some trigger guards and levers, a lean mix at a slightly lower temp initially will avoid any problems , practice on some old parts or scrap bits of metal will help stabilise the mix . Keep parts in the top half of the molten salts, and take care when adding water.
As was said above, definitely an outdoor job.
Last edited by Nick. C; 07/19/17 07:36 PM.
