--- In
Homebrew_PCBs@yahoogroups.com, Alan King <alan@n...> wrote:
> ralucas4277 wrote:
>
> >
> >Wouldn't point tinning take forever by electrolysis?
> >
> >
> How long does EDM take? :) Neither is really electrolysis. It's
> more in the line of electrical discharge with vapor deposition when
used
> the other way around... Just works straight with dry materials clipped
> to a power source for steel and pencil lead..
I don't suppose a high intensity, short range electrolysis process
to remove the copper would work, would it? No, probably not, since
it would require the areas of Copper to be eroded to be connected
to a common plane.
> >Would the graphite be dense enough to act as an etch resist? Would be
> >interested in your test results.
> >
> >
> >
>
> Results on steel are blacker than black, it looks like you've burned
> the steel. Depending on many factors it could take several passes to
> write my name on it very well, but it was to fill in any gaps.
Anywhere
> you had the spark you had a transfer that was almost impossible to
> remove short of grinding it off, it looks like you've burned the steel
> to a cinder where you've sparked it.. I've got to find my lead though,
> all I have on hand is the waxy kind. Works much better with the
> 'graphite' feel leads, the kind that feel cold and gritty and leave
> black on your hands from handling them, mine came from old type
> mechanical pencils. The waxy kind of leads don't work nearly as well,
> probably the binder turning to vapor soaks up the heat. Plus it
takes a
> good battery or supply, needs some amps behind it..
>
> I'll find my stuff and try it out, even if it doesn't work on copper
> or isn't very practical, it works great on steel and it would be neat
> just to see it work and write my name or similar in some steel to
> etch.. Haven't done it in a long time, this is something I played with
> a lot when I was 12-15 or so.. Sort of like making a solder bridge and
> plugging it into 120v, more a gimmick than something I ever thought of
> as useful. Might just work though, but also likely to take a lot of
> other work to get it to do something like a board with it..
>
> As I recall it was quite fun to do and see instant results on steel
> from barely touching it with a wired lead, I highly recommend trying it
> out to everyone whether or not it works for any other purpose..
I have to wonder if the Carbon from the graphite lead may be
alloying with the steel to form a new material. After all, it
sounds sort of like micro-power welding, or, actually, more like
micro-power cutting.
> Alan
Dave