Por 15

[BigBird05]

Severely disappointed in POR 15. 3 years ago I put it on the frame in the engine compartment. This truck has never been out of my garage. I took the cab off to sand blast the rust and decided to power wash the frame. The POR 15 came off in sheets. Now I have to repaint the engine compartment as well as the rest of the frame.

[gmc684x4]

I do not know why it sheeted off

I have learned why bodyman wont touch por15 as it can be brittle and crack lots where epoxy paints will withstand the impact better

[72c20customcamper]

How was it prepared ? Leaving rust (not loose scaly loose rust ) or sandblasting Is recommended if the metal was smooth Shiny metal it won’t adhere well.

[HO455]

With any paint or coating properly preparing the surface is vital for performance. Coatings that come off in sheets is a sign of improper surface preparation.
POR-15 requires a rough surface. It adheres better to a rusty surface than a clean one. POT-15 recommends using a acid preparation before application. The POR-15 will stick to rust fine but not the surfaces around the rust. They must be prepared correctly to ensure the coatings last as expected.

[SkidmoreGarage]

Just to pile on, a good wax and grease remover after some degreaser (even dish soap) will also help with long term adhesion. This is true for any coating.

If you want it quick, fast, and in a hurry- I've had good luck with a quick wire brush, brake cleaner, and a spray on 2 in 1 encapsulation product. Stuff that is spayed tends not to come off in sheets.

[57larry]

I always have a hard time opening the can

[i82much]

I have had it on the frame of my GTO for 15 years, still adheres fine. Agree there was probably a prep issue?

[96blazr]

Originally Posted by BigBird05

Severely disappointed in POR 15. 3 years ago I put it on the frame in the engine compartment. This truck has never been out of my garage. I took the cab off to sand blast the rust and decided to power wash the frame. The POR 15 came off in sheets. Now I have to repaint the engine compartment as well as the rest of the frame.

Just throw POR-15 away, cause it's BS.
THIS is what you need: www.rustbullet.com
Here's their Frame kit: https://www.rustbullet.com/product/u...riage-car-kit/

RB is THE BEST rust inhibitor.....PERIOD!!! (As Greg Gutfeld would say)
I used and I've never had any issue and I'll never have to use it the same area ever again. (Of course keeping my truck in a garage helps too) But, I'm telling ya, do the research and you'll see.

[72c20customcamper]

Originally Posted by ohboy321

I use small cans of POR-15 fuel tank sealer to restore kerosene lanterns and can seal 6-8 per can. I drill 2 holes in the cover and close them up with #10 sheet metal screws between projects. Next time I need it I shake the can, remove the screws, and pour what I need. You can stir it with stiff wire through the holes if you want.

Originally Posted by 96blazr

Just throw POR-15 away, cause it's BS.
THIS is what you need: www.rustbullet.com
Here's their Frame kit: https://www.rustbullet.com/product/u...riage-car-kit/

RB is THE BEST rust inhibitor.....PERIOD!!! (As Greg Gutfeld would say)
I used and I've never had any issue and I'll never have to use it the same area ever again. (Of course keeping my truck in a garage helps too) But, I'm telling ya, do the research and you'll see.

I've used por 15 for 20 years never a problem... There are other good products out there but dont condemn a product that works great

[HO455]

Originally Posted by 96blazr

Just throw POR-15 away, cause it's BS.
THIS is what you need: www.rustbullet.com
Here's their Frame kit: https://www.rustbullet.com/product/u...riage-car-kit/

RB is THE BEST rust inhibitor.....PERIOD!!! (As Greg Gutfeld would say)
I used and I've never had any issue and I'll never have to use it the same area ever again. (Of course keeping my truck in a garage helps too) But, I'm telling ya, do the research and you'll see.

Mighty strong opinion. Here is where my research is done. Here is where my truck lives. Both of them find fault with your opinion of POR 15

"RB is THE BEST rust inhibitor.....PERIOD!!! " Which commercial marine hull and deck coating systems did you compare this inhibitor to?

[bry593]

I'm told POR is a urethane base. Urethane is good stuff, but 2-part epoxy is better. I personally use epoxy since I can get a gallon of activator and a gallon of base (1:1) for the price of a gallon of POR. Epoxy has excellent adhesion on raw steel and when cured is really tough. So tough, it resists a wire wheel. Also stands up to salt and most chemicals although brake fluid will remove the gloss.

As previously mentioned, adhesion is dependent on prep. Nothing will stick to an oily substrate. A good method for underbody and chassis is to wash everything with soap and water using a scotch brite. Then wire wheel or blast any scaley rust. This is followed by a phosphoric acid wash with scotch brite. Then comes the epoxy. Use a roller anywhere possible since it makes for a high build, single coat, and then use horse hair and/or sponge brush for the nooks and crannies. Once finished, it does not come off. You can take a hammer and beat on it, it will not chip and will not flake.

EDIT: Forgot to mention, the epoxy I use is from Anchor Paint (local manufacturer for me). It is an industrial grade, high-build, polyamide coating (highly toxic which means it works), p/n 3900. Anchor can dye it various colors, although I prefer black which appears semi-gloss once applied with a roller. It is not UV resistant, and will eventually color fade if applied to surfaces exposed to the sun.

[72c20customcamper]

Originally Posted by bry593

I'm told POR is a urethane base. Urethane is good stuff, but 2-part epoxy is better. I personally use epoxy since I can get a gallon of activator and a gallon of base (1:1) for the price of a gallon of POR. Epoxy has excellent adhesion on raw steel and when cured is really tough. So tough, it resists a wire wheel. Also stands up to salt and most chemicals although brake fluid will remove the gloss.

As previously mentioned, adhesion is dependent on prep. Nothing will stick to an oily substrate. A good method for underbody and chassis is to wash everything with soap and water using a scotch brite. Then wire wheel or blast any scaley rust. This is followed by a phosphoric acid wash with scotch brite. Then comes the epoxy. Use a roller anywhere possible since it makes for a high build, single coat, and then use horse hair and/or sponge brush for the nooks and crannies. Once finished, it does not come off. You can take a hammer and beat on it, it will not chip and will not flake.

EDIT: Forgot to mention, the epoxy I use is from Anchor Paint (local manufacturer for me). It is an industrial grade, high-build, polyamide coating (highly toxic which means it works), p/n 3900. Anchor can dye it various colors, although I prefer black which appears semi-gloss once applied with a roller. It is not UV resistant, and will eventually color fade if applied to surfaces exposed to the sun.

A lot of epoxy primers don't work well with acid preps . I use SPI epoxy and the recommend using a complete rinse to neutralize the acid. I've hit it with a baking soda wash and never had a problem

[72c20customcamper]

Originally Posted by HO455

Mighty strong opinion. Here is where my research is done. Here is where my truck lives. Both of them find fault with your opinion of POR 15

"RB is THE BEST rust inhibitor.....PERIOD!!! " Which commercial marine hull and deck coating systems did you compare this inhibitor to?

This is a mild winter here

[OregonNed]

Mine's been fine for years. I like the small cans to use one at a time and not have to store a previously opened can. I used their metal prep as suggested.

[Gary 70 Jimmy]

I tried to paint pro 15 on my frame that had been painted with 395a and starting to rust it came off in sheets

[special-K]

It seems every time these coatings come up it ends up in a pissing match between brands. It is obvious this thread was started due to improper surface prep which is no fault of the product. It seems ironic, but the problem here was the surface was probably prepped too well. Or maybe the surface wasn't rusty in the first place and it's use was overkill.

I've used these coatings for a very long time, powder coat as well. Like 40 years or more. Way back when my powder coater told me they do epoxy for interior and poly or whatever the other was... urethane?... for exterior because the epoxy had less give, less tolerant to extremes. But that was a long time ago and I know chemistry in this area has come a long way. There are strong opinions on these products that POR-15 was the pioneer for. That's Paint Over Rust-15. I know people who used it back when I used to who are still happy with it. I switched to Masterseries when I learned of it and educated myself on it vs POR-15. Recently I have learned about the SPI that many members promote with passion, and have also been made aware of some stink going on between those two companies. I think it's a waste of effort to play into that one bit, and I certainly have not and will not. I believe there can be more than one great product out there that will meet and exceed your expectations, just like tire companies and many other things we buy for our trucks.

[HO455]

What he said!

[Peanut74]

I used POR-15, for the first, on my sandblasted frame just to make sure it didn't rust. I used a brush to spread it on. Since POR-15 breaks down if exposed to UV light I sprayed on some gloss black paint. After all that was done I wanted to run a ground wire to the frame. The only way I could get to clean metal was to use a die grinder with 80 grit.

So that is my experience with POR. If you prep the surface right it works great.