I want to use some on my entire underhood area, strut towers, firewall, framerails that kinda thing. My question to everyone is: Have you used POR-15 w/o using there metal ready? Like you just coated it onto cleaned surface or what you done for prep if you DID NOT use the metal ready. If you didn't use metal ready any serious downsides? Like flaking or peeling off? I was told if I didn't use metal ready it just peel off. I plan to degrease the surface good, then use an electric wire brush(on grinder or dill) and my grinder to prep it. Then paint directly over usin 2 coats just as directed. So I'm just looking for answers from ppl who have used por-15 and have NOT used metal ready before using the paint. To see if there's any adverse affect, or if you just had good results.

Ive done two truck frames with POR-15. First was for my dads street rod that we sandblasted and did the proper method. The second was my old S-10 that i just degreased, scraped the big chunks off and went down to the local paint store, bought some acid etch, and used that because thats all the metal ready is. You couldnt tell the differnce between the 2 frames. Both are holding up great. I also tried just using por on the inside of the street rod cab without acid etching the metal and yes it peels right off. Stuff works awsome if preped properly.

Yep, if you don't prep the surface right, the stuff will peel right off.

Another thing to remember is that POR15 turns brownish after a while. So if its a part that you are gouing to be seeing you might want to paint over the POR15 with that other paint they sell.

Not only because it looks bad but because the UV rays will break down the POR and it will protect properly.

i bought the stuff and then read the directions, it says it can only be applied over rust, so my question is will it work over a painted surface or bare metal (ie. sand blasted)?

I deceided not to use it if it only works on rust, my car just isnt that rusty. now im out the 50 bux

i believe that if you use the metal prep you could salvage that 50 bones

I can vouch for the fact that POR15 will not stick to a painted surface. When I first got my TA a few years ago, I found a few surface rust spots on the underside of the body. Wire brushed them down and coated those areas with POR15. Last summer I cleaned and refinished the entire underside of the car when I rebuilt the suspension, and found that the POR15 was peeling where it had overlapped on the painted surface. It was hard as a rock on the areas where the surface rust was previously.
I would recommend that you strip any paint, use the metal prep, and you will be happier in the end. POR15 is a great product if applied properly.

I used POR15 over rust, paint, and bare metal. Both with and without metal ready on each. Followed direction for prep to a T. Didn't turn out well to any of them. (Seems though as it it stcuk to the painted area better? where I had overlapped) Its not peeling or anything but it scrtaches way too easily. Just be sure to use a water based degreaser.

According to POR, it will stick to paint but wont offer the rust protection as it would over prepped bare metal or rust.

also might want to try rust bullet. Haven't really heard any negeative about them. Like POR15, but they claim less prep needed.

i used the metal prep, made all my parts look milky white. I thought that didnt look right. am i wrong is the metal conditioner supposed to turn a dried white color

I am actually still in the process of doing my underbody and frame. I have used the metal ready on rusted, painted and bare metal, and then por-15'ed it. It came out fine. On the other hand, when i was to lazy to spend the 25 bux for the gallon of metal ready i por-15'ed over rust, painted and bare metal, and the por-15 flaked off the bare metal once it dried. But the por-15 on the rust is actually harder then the por-15 on the light rust(after brushing) with metal ready.

/all and all im only going to use the metal ready on the bare metal, b/c i have had good results just slapping it on there. Although I am not looking for a show car underbody finish, or for the paint to make the best possible chemical bond, this is strictly to prevent damage, while not taking me too much time, as I live 200 feet away from some awefully salty water in the north east.