I wouldn't put POR-15 on that tub! POr-15 is for painting over RUST! You have a beautifully prepped tub. It deserves better than POR-15! Also, POR-15 will require more work and possibly more money since it'll need to be primed over before top-coating.
Invest in a good epoxy primer and you'll get much better results.
Invest in a good epoxy primer and you'll get much better results.
Some filler for the pits... This is gonna get some POR and Primer, then raptor on top. Should never rust again...