I've built 18 35-40 ford street rod chassis. Always painted them with POR 15 including the master cylinders. I used a power brake bleeder to bleed the brakes and always managed to get brake fluid all over everything. I just wiped up the brake fluid as soon as practical and never had a problem with the POR15. Make sure the part is properly prepped before painting. No grease or oil and no smooth shiny metal. The POR 15 likes a rough surface for proper adhesion like one that is freshly sand blasted.