For boards that I am not going to tin, I polish the copper real well and give a light coat of Krylon. Have had no problems soldering right through the Krylon, and also works somewhat as a solder mask when doing 1206 size SMD.
DuWayne
Message
Re: [Homebrew_PCBs] White TRF Clearcoat
2017-08-10 by duwaynes@...