Homebrew PCBs

"cunningfellow" <andrewm1973@...> writes:
> Have you tried different brand transparencies?

No, I just happened to have a big box of those sitting around from a
long time ago so I used them.  I was making a single-sided board and
wanted (1) a thick coat of toner on the etch side, and (2) tomer
"silkscreen" lined up on the component side.  If figured, the only way
to do the silkscreen side was toner, and transparencies would make it
easy.  Plus, I'm out of UV film at the moment, and the project had no
small traces, so TT was a viable option.  Figured I'd give it a try.

Based on the results, I think the key thing to realize is that toner
sticks due to a *mechanical* bond.  Transparencies are very smooth.  If
the PCB is less smooth, the toner will stick to it instead of the
transparency when you peel them apart.

Thus, vellum wouldn't work because it's got a matte finish on it.

> With the OH-LUX transfers, I would run cold water
> over the top as it was still hot.

I press the sandwich down on my table saw.  The cast iron sucks the heat
out in seconds, the pressure makes sure the toner is stuck to the pcb
when that happens.