well i've done most of what you guys have mentioned but it didn't get hot tanked but it got the degreasing from hell, complete with cansx2 of carb cleaner to dry out any residual oil in the casting. i've never witnessed any failures with the POR15 as you guys have mentioned. i've given a few blocks this treatment it's never shown any sign of peeling. after i've finished degreasing the block i let it sit overnight, our humid semi tropical air creates a faint layer of rust which helps POR15 stick, i think maybe it's how your prep for that product that makes the difference. here's my block now ready for trial fit of my parts.