Homebrew PCBs

@Dave
thanks for the tip with laquer thinner for solving colophony resin.
i tried it and it is much better than alcohol.
The "laquer" is the same density / concentration in the whole jar, it stays 
good dissolved without stirring etc.
with alcohol it was always thicker at the bottom (with acetone too).
Dries quick and leaves a shiny coat.

I actually tried it as a resin for etching (because the quality is much 
better now).
The problem is the plotter pens i have (carbide tipped) don't leave a thick 
enough layer to resist HCl H2O2.
I will try repeated plotting and maybe try Fe3Cl which i have standing 
around somewhere (Does it decay in a sealed Bottle?).

But i applied it with a piece of wire and with a piece of a paper towel 
"disposeable brush with needle-nose pliers handle).

And this areas resisted the etching very well.
So i think the plotter pens simply make a too thin layer.

any ideas? - would be great to solder the boards with resin layer and also 
protection against corrosion.

st