Homebrew PCBs

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..

>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..

Alan