New 1948 Jeep CJ2a Owners

[bmorgil]

I an pretty sure POR15 is self etching, meaning it is intended to come into contact with bare metal. I have seen a lot of guys paint over it and it works OK like that. It is not intended to go over any type of paint however. That stops the idea of POR15 preventing the corrosion by its chemical reaction with bare metal. If you want to prime (and you should), you can treat the clean de-greased areas with POR15 rust stop/metal prep then some POR15 self etching primer. A top coat of POR15 after that will be rock hard. POR15 definitely works best on clean, de-greased and zinc phosphate coated bare metal.

[LarrBeard]

I'm just watching, but this talk about POR 15 tweaked my curiosity. As usual, Mrs. Google led me to some straight skinny about the product:

https://por15.com/collections/3-step...op-rust-system

From the product description, it looks like it is intended to be directly applied to metal - not over another coat of paint, primer or whatever.

[bmorgil]

Surface preparation and ambient humidity are critical with POR15. It is very susceptible to humidity when applying, and metal that has any contaminate on it whatsoever. I have seen meticulously prepped and applied POR15 come off in strips because it was applied when the humidity was too high. I have also seen it peel right off and leave rust underneath because the surface was not perfect when the POR15 was applied. All that said, I have seen it applied over New Steel and it is still there decades later. With POR15 you must put it on a properly prepared surface in the proper humidity, the drier the better. When POR15 is applied and cured correctly, it is rock hard and is very difficult to remove. When its not, it falls off. I have not had problems with oil based paints.

[2ofus]

Thanks for the insight with POR15, we will change our plans and prep the metal first then apply POR15 directly on the metal.