Technical POR15 Peeling Disaster

I totally hate the "encapsulation" approach to rust. Rust will win. I hate POR15 with a passion, let me count the ways.

I digress. Here's what's up:

Unbeknownst to me, Idiots painted entire underneath of a pickup I purchased 10 years ago. I totally did all the body work and put almost 5 gal of the Chevron Marine Rustproof Compound L (a Kendcote 60 type product) on everything.

Now The POR15 is peeling and causing massive rust damage on a scale like Ziebart.

If you've ever seen this, the POR15 is so durable a paint, you can peel it off in sheets easily over 12" in length. It clings to the rust that is running rampant underneath so that water is held efficiently and rust accelerates and spreads further under the POR15 - sort of like filiform rust does.

I have a hand sized hole in the side of the bed where it would never rust out in 100 years if bare metal.

The deck is corrugated and THE TOPS of the corrugation are rusting through.

WHAT TO DO?????????????????

 

Sounds like an application error (improper preparation). I did the entire underside of my '51 Ford club coupe in the winter of 1987-1988 after sandblasting it. I put the car up on my lift for winter storage last week and had the occasion to check the condition of the undercarriage. Although it's a little dirty and dusty, it is still adhering 100% and protecting like it should.

Whoever did you truck originally seems to have done a bad job.

 

I would have to agree with post #2, a bad job. Anything that I have put por15 on is lasting fine; including spillage on my T-shirts! I Just did a pin hole seal up on an oil pan, previous seal up lasted 10 yrs! I use it in the snowblower, makes for hard slippery surface which lasts for years as long as you keep out of the stones. Even gives dirty hands a new wear surface; not recommended!

 

POR15 will peel off in sheets if it is applied in damp air conditions, it must be a very dry day to apply or else it will rapidly cure before it bonds to the surface.

 

If POR -15 were a faulty product , they'd more than likely be out of business by now .

 

It seems obvious to me that surface was not prepped right.

But that is irrelevant - I have a problem and looking for a solution.

......

The following is Off Topic if you wish to read. Please don't respond about proper usage.

I don't need POR15 pep talks. I have a meticulous German car restorer who used it on a frame prepared scrupulously, and it did not stick. I have a Sears Snow Blower that was painted with polyurethane and have a massive sheet that came off - I should take a pic of it.

I have seen POR15 on heavily rusted metal and its adherence is phenomenal - NOT able to scratch off aggressively bulling a big screwdriver into it. not rusted is another matter.

Even if it adheres properly, I'm not so sure it is not susceptible to filiform rusting.

Further, most people use it on restos that don't get driven in rain, snow and salt.

 

Other than whining about what a previous owner did incorrectly, what is your question? Peel and sandblast the remaining paint from the improperly prepped surface, patch the metal, paint it the way you like.

 

we need pictures. Train wrecks are always popular.

(yeah, I've never used it, the basic premise of P. O. R. rubs me the wrong way)

 

If it's insured, go fishing.

 

I'm with Squirrel on this one. I never really cared for the stuff. I'm an old-fashioned sandblast, primer and paint guy. (sometimes undercoating) I've seen several instances of it peeling off over the years for whatever reason and it looks to be difficult to remove and repair. I used it on a non-automotive project for my Dad with acceptable results.
Of course, I have to take into account that I live in a desert and have no idea what you guys who live in the rust belt have to deal with.
Sounds like you have a whole lot of work ahead of you....

 

Sounds like poor prep to me. I have some stuff that has sat outside for 20 years and driven in rain and snow with no problems. It’s great stuff as far as I’m concerned.

 

The frame of my '96 Ranger ( likely built in Edison NJ ) Spent 90 some thou miles in NJ.
I bought and brought it to De. Another 40 thou here and boom the frame coating exploded.
Same description, paint comes of in large pieces, metal beneath is dark brown deeply pitted.
I am thankful I don't have to love it.

 

Tell’m Gomez.

 

Sounds like you need to remove all of it and kill the rust problem; I can sympathize with the "more rust under the paint than if it had been left bare" situation, had a car with a literal ton of foam carpet pad in it that had kept the floor soaking for years. The pad brought up pieces of floor when I pulled it out. Most aggravating purchase (and disappointing) I'd made so far. There was no practical or cost effective way to salvage that car at that time.

 

Never had good luck with POR products. It may work in dry climates, but my experience is that it will peel off eventually, at least where the climate is relatively damp. It covers the rust initially, but eventually the rust lifts the coating, and it’s all downhill from there.

 

My question was clearly stated in the original post.

Here are my thoughts: use chemical or electrical energy to remove - not human energy:

• Local Commercial Sandblast - all that Rust Proof Compound L will make epic mess, plus operator must not get carried away.
• Paint Stripper
• 13hp Pressure Washing - this would be my pick since great for blowing off the loose POR and be totally non-destructive but the mess would be epic.
• Fluid Film soak at least once a year - it's creeping characteristics are fantastic, 6-8" of creep is common.
• Or adapt a sidewalk cleaner to shoot upward:
  

I'm 70 and will not roll around underneath on a creeper doing anything by hand.

 

In his defense, that was applied OVER the POR 15, if I'm reading his original post correctly.

 

What are you talking about? You didn't read what I posted. I'll reiterate:

I never applied the POR - previous owner did that over 10 years ago before I bot truck - I only discovered the POR recently when all this mysterious rustout started. ​

 

Yea not a POR 15 fan here but then I don't believe in Santa claus the Easter bunny or the tooth fairy...

 

Several years ago I used “zero rust” on my kids roof. Lots of surface rust, da and wire wheel just knocked the “fluff” off.
She wants to paint it, so commenced to getting the Zero Rust off. Took forever, but the roof looked the same.
Mistake I made was using a “rust neutralizer” (I forget the brand, but not a no name) and followed instructions, then laid primer over it and sealed the primer. Shit bubbled up and was a mess underneath.
Anyway, the Zero Rust is some sort of marine paint for metal pylons, etc that live in salt water.
I’m not endorsing it, other that to say look into it.

 

Stopped using it 10yrs ago !

 

This thread is hijacked to POR15 Pros and Cons.

I want to get ideas how to deal with this.

 

you still haven't posted pictures. We can't see what you're looking at. Only you can see it.

 

The solution would use: to peel off the POR15, treat the surface with OSPHO, the paint with rustoleum.

 

'''Unbeknownst to me, Idiots painted entire underneath of a pickup I purchased 10 years ago. I totally did all the body work and put almost 5 gal of the Chevron Marine Rustproof Compound L (a Kendcote 60 type product) on everything.'''

Sorry I'm lost.

 

I think the pressure washer will be your best bet. What is loose will come off, what doesn't will be a real pain to strip. I have used Por 15 on frames and floor pans and sealed inner structures for 30 years. The only problem I had was on some replacement floor pans, should have sanded it for added bite. It pealed right off the new metal, but a 36 grit roloc disc in a die grinder would gum up and wear out and not hardly put a dent in what did stick. Wish you luck. Larry

 

How do you know it was por-15 if it was already on there when you bought it ???
There's several different companies producing and selling rust converters, it could be one of any of them. I had a thread a few months ago about where I had some por-15 issues do to my own mistake of painting over the top of it, I sanded it down, applied their primer then applied Rustoleum without issues.

 

I'm out of popcorn and this movie is going to be good!

 

POR=PAINT OVER RUST. helluva concept huh? Wonder if I can get away with that on the topside of the body? I'd say you can probably use a pressure washer to remove it. Then once it's dry, wire brush what you can, and use some rustoleum paint and a brush.

 

The 'paint over rust' concept never agreed with me but using POR over properly prepped bare metal can protect metal for decades. Its all about adhesion and creating a moisture and air barrier. Nothing promotes great adhesion better than a sandblasted surface that has been thoroughly rinsed with a prime wash. I prefer that method over a chemical etching system. I only use POR on areas not subjected to direct sun or ultraviolet light. Use of a suitable top coat to protect from sunlight prevents the POR from degrading and turning milky.
Any cheap roll/brush on paint such as Rustoleum, Armour Coat, Tremclad or the like will prevent further corrosion for a time but longevity requires paying the price in most cases. I have been using a marine enamel called Interlux lately on chassis, floors, etc. over Epoxy primer. Tough as nails and time will tell how it will last longterm.