Techspray Techform TC-533 Peelable Latex Solder Mask, 1 Gallon

Techform peelable mask is a high-temperature flexible solder masking compound specially formulated of natural latex rubber. Prevent solder from flowing into contacts, terminals, screw heads and plated through holes.

Latex has been chemically enhanced so that it is heat stable enough for wave soldering processes. Effectively mask and protect the board from the time it is manufactured, through all assembly and reflow operations.
NOTE: Not recommended on bare copper because ammonia may cause discoloration.