[sdiy] DIY soldermask coating?

[Dave Kendall]

Hi All.

I've got some long single-sided PCBs I got from the downsizing 
maintenence dept. of a audio visual studio. (Someone suggested they 
might be spare buss bars for an old mixer).  Each has 4 long copper 
traces with several sets of holes spaced across the 4 traces at 0.156 
intervals ( just like MOTM-format power connections). I plan to use 
them as ±15V power distribution boards, but would like to be able to 
insulate the large unused copper areas of the traces, leaving just a 
small area of copper under each hole for soldering pin headers on to.

Anyone know of a relatively tough spray-on, or paint-on electrical 
insulation coating that won't react badly with bare copper? doesn't 
matter if it's opaque or transparent, but it has to do the same job as 
the solder-mask coating on the solder-side of commercial PCBs.

Cheers,
Dave