Tacho - 5-11-2004 at 15:06
The (large) nail in the middle was covered with a strip of insulating tape in a spiral shape, connected to the positive pole of a 12V supply and
dipped in a NaCl bath with a copper cathode. After a couple of hours I had a mini-screw for a screw press. This was just a test. The concept works.
Smooth surfaces, sharp edges.
I wonder what would happen if I use a thin stream of NaCl solution on a given point of a steel sheet... with the proper electric connetions... humm...
a steel cutter?...humm... naa, just use the proper tool.
[Edited on 6-11-2004 by Tacho]
Saerynide - 6-11-2004 at 00:02
Awesome 
Why does it corrode with sharp edges? Afer some of the steel corrodes away, how come it wont start to work its way to the area under the tape from
the exposed area? I never understood why etching could make such defined areas.... 
Tacho - 6-11-2004 at 02:15
I never understood that either. I have seen pieces of marble deeply etched by acid (artistic work) and the edges have the shape of a slope, and start
perpendicular to the surface. Some sort of "etching gradient" starting from the edge is formed, I gess.
I have only etched 0,35mm on steel. Maybe I won't be so lucky when I dig deeper.