POR-15 FAQ'S - Stop Rust with POR-15
https://www.por15.com/POR-15-FAQS_ep_61.html
You should use only
POR-15 Solvent for thinning. Keep lacquer thinner handy for clean-up. Do not
thin POR-15 more than 5%. CAN I PAINT OVER
POR-15 WITH OTHER PAINTS? Absolutely.
POR-15 will accept all paints, including lacquer-based paints.
POR-15 Tie-Coat Primer is the best prime coat to use before topcoating
POR-15.