Ditch the POR15. I have a fiberglass tanked and it failed not once, but twice.
I'd used Caswell sealant. Put that in over a year ago for my fiberglass tank and not one single problem since. Much better product from both a chemical and user standpoint. Best $60 I've spent.
"The bold adventurer succeeds the best.” - Ovid
WTB: Plated KTM EXC450/525 RFS, Honda CRF450X, Suzuki RMZ450