> (2) Datak incandescent-resist.  Having probs sourcing these.  Datak's web
> site claims Austin dealers, but dealers say no more.  Other dealers only
> have remnants left (no discounts), not sure which, and are dropping the
> Datak line.  Still looking.

Neil,

If you really want to try the incandescent boards, you can send me an e-mail
off-list:  I'm pretty sure I can buy some for you.  They're actually easier
to work with than the UV-type.  You just push the transparency against the
board with a piece of glass, this way you don't have any faded traces.  The
boards look very professional, I was able to get excellent results the very
first time.

Now, about direct plotting traces on copper clad boards.  Jacques explains
the process really well on his webpage:
http://www.qsl.net/ve2emm/pcb/pcbe.html

After spending a few days experimenting, here's what my friend and I have
found:

1) Sharpies suck.  Even the "super-permanent" types.  Ferric chloride and
ammonium sulfate eat away the ink before they can get the copper.  Use
Staedtler Lumocolor #318-2 red permanent pen.  I cannot overemphasize how
important this is.  We tried three different types of pens and ruined three
PCB's.  Today, after switching to Staedtler pens, we had our first success.

2) Windows HPGL driver sucks.  You can't have a good plot of a board created
in Eagle, even if you export the gerber file to HPGL and print it from DOS.
We used Protel's free Easytrax software, it has a built-in HPGL driver,
which works great.  I recommend Easytrax for small projects.  Hand routing
can be fun!  :-)

3) An etching tank system is definitely worth the money you spend on it -
about three times faster than etching in a plastic tray, semi-automatic, and
the etching is very even.  We got ours for $40 here:
http://store.yahoo.com/webtronics/lowcosetsysw.html

4)  Ammonium sulfate costs about the same as ferric cloride, but is much
cleaner.  This allows you to monitor the etching process without having to
take the board out for inspection.

The whole process takes about 15 minutes for a 3x4 (100-pin) board  - 7
minutes plotting and 7 minutes etching.  Of course, one can tell that the
boards are home-made, but they are cheap, easy to make and do not require UV
light or developing.

If anyone is interested, I can post the pictures on my website.  I hope the
information was useful.

Sincerely,

Vitaliy

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