Life after POR-15

Well, my experience with POR-15 so far, so good I guess.
Coated my subrails in it, let it dry a few days. Took them to the shop to cut and fit them in place, kind of surprised to find rusty metal under the POR.

Not complaining mind you, but I thought the POR would soak into the rust and convert it into a structural part of the metal. I mean, it does cover and coat very well but how will this affect future metalwork on these parts? (Welding, grinding....)

Any thoughts on this? Like I said, I'm not complaining

John

 

POR 15 encapsulates rust. as far as I know it does not convert it to anything. the deal is that the gases formed in the rust process can not bubble the paint to escape. plus it sticks to rusty metal where other paints will not.

that's how I got it figured anyways.

 

I always wire brush down to fairly solid surface. Not necessarily no rust, but not any loose or thicker stuff. PPOR-15 is a coating, so it does not change the rust. You will need to remove it before welding, just like any contaminants on the surface, get to good clean metal.

POR-15 stops the rust by keeping the moisture from getting to the surface. No more rust to continue forming, or new rust.

 

POR-15 will not stick to smooth surfaces or any other coating. It likes rough metal, but you want it pretty clean. They sell a phosphoric-acid rust 'neutralizer' they want you to use before paint, but if I were to use POR-15 again I might be inclined to use something like Rust-Mort first.

Note that nothing will stick to POR-15 either, unless you either get some other primer on it while it's still tacky or roughen the crap out of it everywhere. It also disintegrates from solar UV very, very quickly unless it's topcoated. In my experience raw black POR-15 will start discoloring after one day in the sun and start peeling after about two days of sun exposure.

After that I hauled the frame down, had the rest of the POR blasted off, and had it powdercoated

 

POR 15 and the other "converters" are a band aid. Rust must be removed. Anything else is a compromise. Do it right or do it over.

 

Amen.

I always laugh to myself when I read about guys using POR-15 type products thinking they have solved all their rust problems. They never seem to learn. It will be back unless you blast it off before you paint.

 

I use POR15 in areas non accessible only. I have a special SATA gun with a 5 foot hose and radial nozzle (everything takes an expensive special gun!!). I snake it inside rockers, A, B, C pillars and anywhere else you can't get to. It seals the surface of air. No air, no oxidation. If previous rust is sealed, it will not oxidize further.

 

In the olden days, that's what you did with your used motor oil...

 

I have tryed to use it every different way and its a waste of $$$ I have better luck with rustolem. If its important enough automotive etching primer and sealer then a good enamel are the only way to go.

 

Well I certainly wasn't going to use it on any surfaces that I plan on seeing or painting. I was just commenting on the supposed lack of absorption into the rust.
I'm quite pleased with the areas I coated.

 

Can I ask why you wouldn't just remove the rust? Maybe its just me, but I have way too much work and money in my cars to short cut when it comed to rust.

 

This is not off topic: http://www.thesamba.com/vw/forum/viewtopic.php?t=131753

^All of those products were tested for 6yrs and they all pretty much failed.

 

If rust convertors actually turned rust back into steel, wouldn't we just use that to make new steel instead of the expensive and hot smelting process? Just hose down a scrap yard and voila... sheets of new steel.

 

I used some on my '50 Chevy 4 or 5 years ago. One spot over the right A-post bubbled up, but it was rusted on both sides and I only painted the outside. I mainly got it to use under the windshield gasket, as these like to rot there.

Now the places inside the doors, where I painted without really cleaning mostly just to use up the stuff I'd poured out, since you can't put it back in the can? Are just like the day I coated them. They were rough with some surface rust when I painted them. I don't know how you get inside there to really get all the rust out, so...

 

I havent had good luck with it.

I cant see it being better than Imron. Imron is good stuff.

I have tried it a couple times, and once you open the can, the remaining product hardens up. Like a rock.

 

Well after reading all the praise in other threads on the HAMB, I thought I'd give it a try. Other than the subrails, I did interior surfaces of surface rusted body panels, and inside hidden channels in the windshield posts.

 

I saw that is a Studebaker service manual, remove sill plate and pour used motor oil into holes on tops of rockers......

 

It has its uses. The windshield post are not a bad idea. I soak seams and over lapped panels. But its way over used. I never paint prime or fill over it. I usually blast the area again after application and remove all trace on exposed surfaces before priming

 

They turn one form of iron oxide into another form of iron oxide which is basically inert.

 

POR 15 is useless. Seen it 1000 times. have 3 cars that customers coated them with and it flakes off everytime. Prepped or not.

 

at the end of the day, its how you prep it.
nothing lasts forever!

imron is tough stuff!- although i like centari better

 

That post mentioned High zinc content paints, and even referred to on as galv...and called it a weldable primer...is that what they do to make primers "weldable"? Welding galv or zinc coating produce severely toxic fumes. I was thinking about using some of that stuff for a project I was working on, I guess I will have to rethink that a little...

sorry to derail the thread, not my intention, but the thread brought up the issue..

 

Geez, I must be the exception. But I have never used it over rust, I always sandblast, clean the metal and spray POR 15. Only on frames, inner wheel wells, under the car, etc. No where the sun shines. But I live in Phoenix where rust is a scarce word.

 

I have used it pretty extensively on Interior pannes afer prepping and removing as much rust as i can. I think its a great product if used properly. I would never use it on anything i intended to topcoat. I use it alot for Floorboards on the inside of cars, holds up great!

 

Thanks. My comment was intended to be snarky. I understand their claim to how it works (actually, POR-15 does not even claim to be a "converter"). Further to my original comment, a pile of "inert iron oxide" is obviously not what cars are made from. Turning a pile of flaky rust into "inert iron oxide" ... it's still flaky "inert" rust, not something to build with.

/2 cents, maybe less

BTW, I've used the product. And I removed scale rust completely Parts that I didn't topcoat peeled up in about 6 months. Parts that I did topcoat looked like I had tar mopped the part because it never leveled out. In my case, it was a daily driver's frame rail, so I accepted the results. But I won't buy the product again.

 

Yep, it got enough UV to make it peel.

It's not really intended for a finished surface.

My main gripe with POR-15 is it's a lot of work for what you get out of it.

Yes, you can put it over rust, but you can't put it over even a whiff of another coating, or filler, or seam sealer (it won't stick at all) or clean bare metal (it will stick poorly.) And it sticks to itself better than it sticks to anything else, so if it peels off some seam-sealer it will pull the POR off the adjacent metal too.

So you have to strip and abrade every bit and every corner of every surface you want to put it on to make it consistently rough enough to take the POR. Then you have to get something else onto it while it's still tacky before you can put any kind of sealers, fillers, undercoating, etc. on it. And I've mentioned the sun exposure issue.

 

Hello friend thanks for sharing out such important information about POR-15..I hope I will be able to make better use of it..

 

I had a bad experience with POR 15. Followed the instructions to the letter and it still wrinkled/pin holes on me. Going forward, I will be using CATALYZED paint or powder coat.

 

JMHO,but por-15 is not a magic bullet,,it's a quick solution to a long term problem.

Best to sand blast prime & paint. HRP

 

people seem to be confused as to what POR 15 is. Paint Over Rust 15.

wire wheel over the rust, brush it on unless you either want to die, or have a proper fresh air resperator. it does not remove rust, it does not convert rust into anything. it covers rust and sticks to it. it dries hard and the gasses escaping from the rust can not bubble the paint.

all you have to do is read the can. this is not rocket surgery.