POR 15 results

gnsrule

Member
Joined
May 27, 2001
After sanding the bottom side of the 86 and knocking off 50 lbs of rust and stuff i final cleaned everything w/ laquer thinner and shot it w/ por 15. It workd great on the steel that was rusty, but on the bare clean steel it didnt stick. It pulled off in sheets. I really didnt wanna go the route POR sugests w/ useing a water rinsed etching fluid since they say POR 15 is so sensitive to water.
I got a quart of self etching primer, ( w/ zink chromate), and shot the bare steel spots w/ that, and then the POR 15. Checked it this morning, so far everything looks great, but its not dry yet :confused: Its in a heated garage and the last time it dryed fully overnite. Hmmmmm.....
I cut it w/ laquer thinner so i could spray it, waited over an hr for the self etching to dry. I wonder whats up
So far so good tho, it looks like a million buks :)
Hmmmmmm, 1m on EBay ?? :p
 
When I did the frame on my 87 I used POR-15 metal ready etcher.
I put it on and then rinsed it of with water, let it completely dry.
It turned the frame white due to the acid's in it i suspect.
I then proceded with the POR-15 then sprayed it with chassis coat black. It is hard as a rock, POR-15 actually gets harder when contacted with water.
 
It really sucks on bare metal as you found out. :(

I don't have that problem however so it worked fine for me on the rust. :)

I liked the way it worked on the frame so much I did the outside of the car as well at least where the rust was. Unfortunately it turns dark gray in color but that's still a lot better than what it used to look like. ;)

Great stuff. I wish I had a sprayer, I used their 1" brushes.
 
POR 15 is great stuff, but you really have to follow directions. POR has to be applied to bare steel to be effective. If you apply it over primer, it's only as good as the primer itself. You may as well spray it with Krylon if your using a primer!

The surface must be very clean and prepared properly. Scrape off all loose rust, sand blast or use POR metal prep on clean steel. I use a strong degreaser such as Greeze Off or Superclean and rinse with clean water. DO NOT USE AUTOBODY PREP CHEMICALS such as prepsolve to clean surface. Using such chemicals will interfere with the adhesion of POR 15.

Thinning it is also not the best thing to do! It is best applied with a brush. Apply first coat and let dry until it it won't come off on your fingers but still feels tacky, then apply a 2nd coat. If you wish to top coat with paint, mist the second coat with primer before it's completely dry. Paint will not stick to fully cured POR 15 unless you do this, or you will have to scuff it before painting (huge PITA) .

In my experience with the stuff, POR 15 black or silver is the best to use. The satin black seems to dry porous and does not hold up well. I have spoken to the manager at Por 15 labs and they insist it's as good as the rest, but I never had luck with the satin black.

Hope this helps someone:)

BTW; POR 15 link http://www.por15.com/index.html
 
I used POR 15 on the T top center sections that were rusted. Found them when I was stripping my GN to repaint it. Sand blasted them and it adheared just fine. I also ended up painting the front suspension parts and the rear brake drums with it and it's holding up just fine. Gonna do the frame next.
Tarey D.
 
As a reupdate, the self etching primer work'd great :D As far as compareing this to shooting it w/ Krylon, thats BS. I did the por for the fact thats its a tough paint that will resist a chemical clean up of brake clean when necessary. We've painted many tractors w/ Imron paint in the construction industry and the prep is Zinc Chromate primer ie: self etching. 10 years later the paint still shines, its all there, and is hit w/ a power washer from drivers. What more can ya ask for :) POR is in the same catagory as Imron being that its an Epoxy, just this is a Modified epoxy, part A and B in the same can, seperated by a solvent, that when it evaporates, it then lets parts A & B mix doing there stuff. At least thats what im told. Sounds right to me.
Back under my rock
 
I'm not comparing self etching primer to Krylon:rolleyes: POR 15 needs to be in direct contact with the steel be be effective! If it is applied over any type of primer, the POR 15 is only as good as the paint underneath it as far as rust prevention.

If your going to use a primer, why waste your money on POR 15:confused: A decent automotive grade enamel will be just as good as you stated.

Another note, POR 15 is not sensitive to moisture in a bad way. It will actually cure faster in humid conditions. ( the exact opposite of enamels) Moisture actually strengthens POR 15!

The correct way to prep bare, clean steel for POR 15 is by sandblasting or acid etch(POR 15 metal prep). They do not recommend primer of ANY sort under their product. I'm not slamming you for how you did it on your car. But if other people are buying the product for it's rust prevention capabilities, your way is not the correct way!

MY advise..... READ DIRECTIONS.
 
I'm of the opinion that POR-15 is not as good as it used to be. I used it 10 years ago and I really think they have reformulated it. It never used to peel like it does now.

But anyway, if you use their metal-etch, I found you have to get all that white stuff off otherwise the stuff will peel. If you don't use an etch, it's coming off for sure :)

I also found the chassis top-coat was crap. It's supposed to be UV proof and yet it turned dull black/grayish on me over the black POR-15.... within a month. That's nonsense for something that's $40 a quart to your house. It's sitting in my cellar now.

I think POR-15 is great on rust and questionable on bare metal.
On bare metal I think there are better alternatives.

Next time around I'm trying Eastwood's rust encapsulator or Hirsch's Miracle Paint.
 
I didn't start using POR until the last year, so although I don't know what it "used" to be like, I *DO* know I am pleased with the results I get now.

I do believe the key is that new bare metal MUST be etched, just as POR recommends, using their "Metal Prep" solution (PPG makes similar stuff that I'm sure would work, too).

About 8 months ago (?) I stripped and repainted my K-Blazer's receiver hitch with POR15 black semi-gloss & then top coated with Chassis Black. Adhesion is great. I have tapped it intentionally with a ball peen hammer and NO chipping. Appearance looks fine, no fading.

On a new GN gas tank , I etched it with with "Metal Prep" solution, 2 coats POR15 semigloss primer, 2 topcoats Chassis Black, and adhesion so far seems fine. Tank's not yet installed, but after the POR has cured (takes 2-3 days for maximum hardness), it cannot be scratched with a fingernail (I'm not going to bang it with a hamnmer to test!).

On the downside,

- it's expensive
- once can's opened, shelf life is limited, maybe a few months tops.
- cleanup is a pain.
- generally hard to apply without brush strokes, some bubbling, etc.

BTW, I believe POR is technically a "moisture-cured, 1-part urethane".
 
If your going to use a primer, why waste your money on POR 15 A decent automotive grade enamel will be just as good as you stated.

I did the POER for the ainti chip resistance and for a chemical clean up w/ brake clean if necessarry. Enamel will work fair for that, but POR should be better.
As far as following the directions, i know all about the water rinseing etching fluid but couldnt see breaking out the garden hose in my garage in the middle of winter for this, and then haveing to blow dry the frame before applying the por ie: following directions.
Tow Man, I guess the " proper " way of doin it would be to sand blast the whole thing down to bare metal and then etch, but i aint doin that, where the factory paint stick'd, I left it. Same for 99% of the ppl here. Im just giveing my o2 of what work'd and what didnt. Take it for what its worth. BTW, at $40 a qt., it's worth alot.
 
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