862-250mL Peelable Solder Mask

https://www.mgchemicals.com/products/soldering-supplies/solder-mask/pcb-solder-mask/

This PCB solder mask is a synthetic latex product for the temporary masking of circuit areas and contacts against solder, rosin and cleaning fluids. This PCB mask provides effective protection for contacts, gold fingers and printed circuit card edges, and can easily be peeled off once the wave soldering process is complete, and after any subsequently applied conformal coating is sufficiently dry. Our peelable solder mask can be applied by hand or by template screening, but not by silk screening. It can also be applied using robotic or pneumatic systems.

Features & Benefits
Withstands Wave Soldering
Non-Corrosive—Safe for copper, gold, silver, and solder joints
Solvent Solubility —Largely insoluble once cured (flux and cleaning solvent resistant)
Water Soluble—Can be thinned with deionized (D.I.) water to adjust viscosity
Immersion Resistant—insoluble once cured
Room Temperature Cures or Quick Heat Curing
Cure Monitoring Color Change—Changes from opaque pink to translucent red once cured
Ammonia Free—Does not discolor copper traces