POR-15 take 2

I purchased a pair of rock sliders several months ago and threw a couple of coats of POR-15 on them. I noticed not too long after that the POR-15 started coming off in sheets. I removed all of it and let them sit bare metal for a couple of months as I was away on business. I knocked off the loose rust with a green scrubby pad and washed the sliders in soap+water. I let them dry for a couple of hours, wiped them down with a clean dry rag and applied the POR-15. From what I’ve read, it should bond pretty well to the rusted metal.

 

Need to top coat . No protection from sun . They recomment if going to top coat when its alittle tacky yet to hit with dust coat of primmer so top coat has some thing to bite too.
Used por 15 before love it .

 

Looks nice

 

POR15 fails if theres no top coat.

 

Also, I used their metal prep and degreaser for my control arms and they still look perfect after 1 year. Take your time prepping and yeah you'll need a top coat to protect it from the sun

 

I have a top coat. I sprayed the oem black over it!

 

Makes sense. The part of the rock sliders that weren't exposed to the sun was still pretty well protected.

 

Prep prep prep and then prep some more.

 

I’m planning on using POR15 on my truck’s frame and as much as I can this summer. From what I’ve read it’s orerty amazing stuff.

 

As long as there is rust it will bond to it. My first application didn’t go so well. I did everything I was suppose to as far as applying it except put a top coat on it. The slider that was most exposed to the sun didn’t last very long.

 

I know you cleaned it but did you use the POR degreaser and, I suppose more importantly, the metal treatment.

I have a thin layer of surface rust pretty much all over.

 

Did you use their metal prep stuff?

 

None of that would have helped, it chemically degrades when exposed to UV rays. If the area sees any sun it has to be top coated, its not optional.

 

It shouldn’t peel off in sheets though. Sounds more like a prep thing. If it’s UV degraded then it just fades and turns to crap.

 

I know that but I was referring to the surface prep done to the sliders prior to application.

Edit: Like Jdevtac said above.

 

Nope its loses its bonding ability and breaks in sheets. This isnt normal paint.

 

Just did a quick search. It sounds like UV causes it to break down and lose it's bond with the rust under it and then it fall apart and just comes off.

Another example of it not being at all like normal paint is that it cures faster with more humidity to a point.

 

Have you had this happen personally? I’m not questioning what you are saying just curious.

 

It’s essentially super glue.

 

Exactly, the composition of POR15 is pretty interesting, it has things in it like titanium dioxide and isocynaic acid etc. Most of it is classified as "trade secrets" but yeah, once exposed to UV rays decomposition is pretty rapid as the "paint" undergoes a chemical reaction due to the energy from the sun.