Not the first note of the music which moves me
- Leeds, West Yorkshire
I have been cleaning the anodes (waste metal) and that's why I'm seeing that they aren't disappearing at any noticeable rate. they are quite big in fairness but thought I'd see some etching
From my experiments in etching mild steel, and table salt as the electrolyte, a rough rule of thumb seems to be on the order of 0.1mm/sq.in per hour per amp.
(Bit of a mish-mash of units, but it makes for nice round numbers).
Basically, if you're using a 100mm square of mild steel, and using an amp of current, it'll take 16hrs before you can feel the etch with your fingernail.