Sorry, don't mean to jack the thread here.
Grayzer, do you have salt or 110 for electrolyte? Salt doesn't etch as well as 110, but it darkens better. #94 works great for both. I'd send you some, but it wouldn't make it through customs on it's own.
Adam, perhaps I mis-spoke when I called it a waste of electronics. When I built the unit, I decided that an arcade style activation button allowing short, repetitive etches was far more useful than a variable voltage that rarely gets used. As far as 16VDC is concerned, it's a trade off between time and not destroying stencils. Identical results can be had with 3VDC it just takes a lot longer.