Por-15 Review

I decided to use POR-15 on a customer's truck since I've had really good luck with it in the past. I got the entire kit with the metal prep, de-greaser, and paint. Everything was power washed twice, then cleaned with wire wheels, de-greased, and then metal prepped, and then finally the por de-greaser. I painted the entire front of the frame and suspension with the truck in the garage. Fast forward a month the owner wants all the front stuff gloss black. I go to scuff it to top coat it and the por on the engine cross member and inside of the rh frame rail just peels off. Every where else is fine. What gives? None of the por from the firewall back had any issues. I scuffed it all and shot raptor liner over it. I did notice that this por was a royal pain to apply. It was not like the por I've used in the past that covered bare metal pretty easily. This stuff wouldn't stick to some areas in a stroke. It needed multiple and then you had to be careful to not let it run. I don't think I will buy POR again after this experience.

I've never used it myself but, everyone seems to rave about how "tough" it is..
Sorry for your trouble but glad you're able to work through it..

I've used it before where it wouldn't come off with a hammer, and other times it peels off in sheets. Because of inconsistent results, it has to be a last resort for me to use it. I'd rather go through the extra work to media blast / abraded something properly and use a good epoxy primer that is made for automotive use AND has compatibility with other automotive paints. The snake oil POR grew out of a coating used on steel bridges. You see how long it lasts there too. Most of their positive accolades read online are from home enthusiasts that are tickled right to death they didn't have to media blast or sand or any of the other "hard" work. If you look past those you'll see examples such as your own, along with other horror stories of the rust accelerating once it's under that "encapsulation". If it's your own project, you get to live with the results, good or bad. If it's a customer car, welcome to rework. Do it right, do it once.

I believe that POR15 is a close relative to powder coating, where the "sheeting" effect is great if it bonds as expected/advertised, but is a curse if it simply forms a sheet that's floating free of the surface, and heaven help you if moisture gets underneath that floating sheet, because it will hide the rust monster until the sheet breaks free. Not a fan.

That's exactly how it came off. In sheet like fashion. Definitely not cool. Maybe those areas were too clean, as in no rust had been there before? IDK I stripped all the loose stuff this morning.

When I did the rear of the frame, the frame had a lot of pitting so I spot blasted it. Then I used etch primer, then the por, then raptor liner. None of that was loose when I scuffed it with 80 grit to prep for the raptor liner. These new bare spots up front will not get the por. I'll use the etch primer, sealer, then urethane paint. I'm over this project. :LOL:

interesting thread on the spi site about it. used under a dodge truck and ended up replacing the whole floor. makes a nice rust sandwich . ok for farm stuff but it does not stop rust.

Well I for one am done using it. I won't get burned again. $209 for their "kit" of problems and head aches.

The products they sell in the kit came out of necessity when the paint started peeling on them.. Then a person like yourself follows all the instruction to the letter and it still peels. Read online and you'll see all those who have drunk the Kool-Aid will say any peeling issues and you obviously didn't follow the instructions. Seems all they have done for their $50 quart of peeling paint is to increase the price 3X. Sorry I didn't see you ask about it ahead of time, I know Shine and I both would have steered you away from it.

I guess I'm the one person in the bunch that still raves about POR15. As a matter of fact the more rust you have the better. But sad to hear about the bond issues. When I went to box in my frame, it took an angle grinder to get it off. It repeatedly out performs any other product I have ever used, their engine degreaser is phenominal too better than any other product I have tried. Not sure what happened here! I would use it again without a second thought!

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Originally Posted by stovens

I guess I'm the one person in the bunch that still raves about POR15. As a matter of fact the more rust you have the better. But sad to hear about the bond issues. When I went to box in my frame, it took an angle grinder to get it off. It repeatedly out performs any other product I have ever used, their engine degreaser is phenominal too better than any other product I have tried. Not sure what happened here! I would use it again without a second thought!

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Hope you feel the same way in a few years, especially given that you live in the Great NorthWet where it's going to be subjected to healthy moisture. I agree with Shine and Robert. I have a can of their "Chassis Black" aerosol which I grab if I have a need for non-critical corrosion protection, like on a tractor or lawn mower.

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Originally Posted by 40FordDeluxe

Well I for one am done using it. I won't get burned again. $209 for their "kit" of problems and head aches.

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Ouch!! well that sucks.. thanks for posting the issues tho', you've prevented me from ever trying it!

I also have had mixed reviews, there are very few products that are the cure all or as good as all the hype (gotta say I am impressed as heck with SPI though) but I have used plenty POR in the past, enough that I will probably be sprouting a extra arm or something due to it being pretty caustic. Most degreasers that have the "slick" feeling left on your hands is just a Phospheric solution, no magic there and most are based on that, right down to purple power etc.
I won't use the POR much anymore but will the engine paint, I had a motor that was painted with it and the machine shop couldn't get it off with there cleaning process. I think sometimes good ol' epoxy primer with a good paint on top is simple and easy to touch up, if it can get powder coated thats what I tend to do as well. sorry to hear your problems though.

How do you guys feel about using something like
Rhino Liner type of treatments // coatings for those items?

Moisture control and degreasing is paramount just as it is when doing body work?
Run a dehumidifier or place a few DampRid type things around the area of application?

Just some questionable ideas from the outside looking in.

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Originally Posted by t-top havoc

How do you guys feel about using something like
Rhino Liner type of treatments // coatings for those items?

Moisture control and degreasing is paramount just as it is when doing body work?
Run a dehumidifier or place a few DampRid type things around the area of application?

Just some questionable ideas from the outside looking in.

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I put raptor liner on this truck and they say that the raptor liner has rust preventative properties. My concern, and the reason I used the por, was to try to stop any rust growth before the raptor liner was applied. I always thought in the past por-15 did just that. Stop rust from growing or forming. We used several of their products when I worked in a body shop 15yrs ago. I spoke to my old boss today and he said por sold out a while ago off the record and cheapened their products. he said he quit using them because he had 2 cars come back from the stuff peeling off and floor pans badly rusted. I wish he would have said something sooner. That is no good.

So what is a better product to use in a situation where the body isn't coming off the frame and sand blasting isn't an option? The owner of this truck didn't want to spend the money and time to do all that. The POR-15 was the way he wanted to go. Or even for a sprucing up of an old truck frame? My eyes and ears are open. :LOL:

Roger it's been on the frame for over 7 years, it ain't coming off. Still stand by it

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Originally Posted by 40FordDeluxe

So what is a better product to use in a situation where the body isn't coming off the frame and sand blasting isn't an option? The owner of this truck didn't want to spend the money and time to do all that. The POR-15 was the way he wanted to go. Or even for a sprucing up of an old truck frame? My eyes and ears are open. :LOL:

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Ryan, it sounds to me like you might consider a rust converter, which chemically changes iron oxide to iron tannate. I would think that you could pressure wash the areas to be treated, let it dry and then apply the rust converter. Google "rust converter" and see what you think. Here's one that looks like you might be able to spray on, but I'd check the FAQ's first - https://www.theruststore.com/Rust-Co...AQs-W48C2.aspx Follow with your paint of choice, maybe like Rustoleum's industrial line since you're not looking for show quality.

rust is better left exposed rather than cover it up with an encapsulater. just leave it be and it will not get any worse. when it is covered with dirt or mud it grows. ever wonder why cars rust in the bottom of the doors or floorboards? because it is covered by dirt. when the por or other such crap falls off usually nothing is left. paint it with a rattle can it will live longer .

I've found rustoleum to be problematic in appplications other than a single coat. It tends to blister and wrinkle if additional coats are applied.

For rattle can applications, I use Krylon.

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Originally Posted by shine

rust is better left exposed rather than cover it up with an encapsulater. just leave it be and it will not get any worse. when it is covered with dirt or mud it grows. ever wonder why cars rust in the bottom of the doors or floorboards? because it is covered by dirt. when the por or other such crap falls off usually nothing is left. paint it with a rattle can it will live longer .

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Believe me, I should have just rattle canned the dang thing. It would be done by now! :LOL: Maybe in Texas you can get away with leaving the rust, but that won't work too well here with the crap they put on our roads.

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Originally Posted by firebird77clone

I've found rustoleum to be problematic in appplications other than a single coat. It tends to blister and wrinkle if additional coats are applied.

For rattle can applications, I use Krylon.

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I've had horrid luck with Krylon products not wanting to dry so I quit using them.

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Originally Posted by rspears

Ryan, it sounds to me like you might consider a rust converter, which chemically changes iron oxide to iron tannate. I would think that you could pressure wash the areas to be treated, let it dry and then apply the rust converter. Google "rust converter" and see what you think. Here's one that looks like you might be able to spray on, but I'd check the FAQ's first - https://www.theruststore.com/Rust-Co...AQs-W48C2.aspx Follow with your paint of choice, maybe like Rustoleum's industrial line since you're not looking for show quality.

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I'll definitely look into this. Hopefully I won't take on any more of this type of stuff for others. :LOL:

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Originally Posted by stovens

Roger it's been on the frame for over 7 years, it ain't coming off. Still stand by it

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How many of those 7 years have been driving with rocks hitting it etc? Another thing to keep in mind, I bet your 7 year ago made POR is not of the same quality as today's. Here is a pic of part of the frame that peeled. Other areas around that spot are glued on. Then you have more peeling next to it. I found these awesome spots while scuffing the por to top coat it. Luckily for me, from the leaf spring hangers back I used acid etch primer, then applied the por. All that stuck fine. I scuffed all that with 80 grit and then applied raptor liner. It should be good to go now. From the front shackles forward the customer wanted smooth and shiny. I should have messed up and just applied raptor liner to it too. It would have been done last week! :LOL: Keep in mind this is on a 550hp diesel mall crawler. (If it matters) Haha

I have stripped the peeling por with paint stripper and wire wheels. Hopefully in the morning I can mask it all off and get it shot. Then it will be time to paint trans, tcase, and then assemble the engine.

I've tried replying a few times but the site seems to go dead!
So one last attempt! We used to apply (brush on) phosphoric acid ( I believe it was) and let it dry, then wipe it down with clean rags / towels and then spray on paint. I think it does what you're asking, oxidizes the rust so you can topcoat over it.

If it matters to anyone, Rustoleum's Industrial product doesn't come in rattle cans. It's only in bulk containers, and it has a specific primer that goes with that line. It can be sprayed, but in a traditional spray gun with enough orifice to flow the paint. I used it on about 200' of custom deck railing, and after five years it looks like the day it was sprayed. Rattle cans are for hobbys.

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Originally Posted by rspears

I believe that POR15 is a close relative to powder coating, where the "sheeting" effect is great if it bonds as expected/advertised, but is a curse if it simply forms a sheet that's floating free of the surface, and heaven help you if moisture gets underneath that floating sheet, because it will hide the rust monster until the sheet breaks free. Not a fan.

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I'm with roger on this, it's not something I would use again as I used it exactly as instructions and found it lifting after 6 months, luckily it was only a test piece and not a complete frame :eek:

I figured I'd post pics of the project after I shot some single stage on it. No more por.

As Stovens said the more rust the better, if those spots that you noticed the por peeling from didn't have any kind of surface rust i would imagine it probably didn't have anything to adhere to. It's really not meant to be used as an undercoating per say, but rather as rust inhibitor for particularly bad places. We use it on the under side of hoods and floors for the most part. Works excellent on a frame too but sand blasted and epoxy prime is best for that.