Homebrew PCBs

leon Heller wrote:
>   
> Red fuming nitric acid should dissolve it, as it is a resin, but it
> will 
> also dissolve the copper and the fibreglass resin, if you aren't
> careful.

All the care in red fuming nitric acid will destroy any solder, pads,
pins and tracks under soldermask.

Normal people simple scratch it with a not sharp tool when repairing a
damaged track. But the exposed problem is understandable.

If one wants a chemistry, hot desmear (or etchback) solutions used in
PTH (or multilayer) production before plating activation seems to fit.
Like permanganate, or better, ethanolamine based solutions. But there
are also epoxy glue cleaners on the marked.