On Aug 30, 8:18 pm, scutt wrote:
I am helping my 11 year old nephew make his second knife ( First attempt
won him 1st place at the Fair :-). I want to keep introducing new skills
so the plan is to try etch in a simple design on this knife . The steel
is an old leaf spring . Does anyone know what to use as a resist and
which acid would work for this application ?
Ken Cutt

Wax, beeswax would make a good resist.
Since he's only 11, I'd suggest HCl, (muriatic acid).
It will work, (a bit slower), and is a bit safer than sulfuric or
nitric acids.