can anyone tell me how por 15 can combat against rust, is it as good as some people say, i hear to knock of the surface rust and dont worry about all the rust because por needs some rust to cause it to react. i have never heard of that before.

i have a 70 chevelle that had the vinel top removed just to reveail a lot of surface rust and some pits of rust.... i have used a D A sander and a die cast sander and even used some sanding to some of the top. there is still good metal underneath all the rust. i am going back with a vinel top and just want to prep the top before hand. someone who has used por 15 on serios rust problems needs to tell me how it works on something like i am up against and how to apply it. thanks so much in advance..charlie

I used POR15 on my frame off resto with great results. It can be a pain to work with and requires a lot of attention to detail. I have a couple parts where I skipped a couple steps and now I have rust coming through. Here's basically what you have to do for POR15 to work properly:
<UL TYPE=SQUARE>
<LI>Remove all loose rust
<LI>Clean the area with a heavy duty cleanser(I used Greased Lightning)
<LI>Spray the area with their Metal Prep.
<LI>Let it dry to a chalky white, then rinse it off with water. As soon as it dries, you're ready to apply the POR15.
[/list]

Check out their website: POR15.com (http://www.por15.com)
I would also do a search on this tech site for POR15, there's quite a bit of info. about it and their experiences with it.
Good Luck!

Jeff
'67 Malibu Hardtop

[This message has been edited by Badblu67 (edited 07-20-2002).]

I wouldn't use POR 15 under a vinyl roof. A good epoxy primer will seal the metal before you put the vinyl back on.

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Redrum (or Mike)

68 Corvette - 383 CI, 427 HP, 700R4, 12.56 @ 108 MPH
69 SS Chevelle - 502 CI, 610 HP, 2004R, 1320 unknown
97 Z-28 - totally stock still under 14,000 miles

"Oh, you hate your job? Why didn't you say so? There's a support group for that. It's called EVERYBODY, and they meet at the bar."
*Drew Carey

To answer your question:
All PAINTS allow moisture and air to go through itself to the the surface it's applied to, although it's minimal. However, if rust (oxidation process) has already begun before the paint goes on, The minimal protection it offers is not enough for the oxidation process to continue. POR-15 and other similar products which ARE NOT paint, actually prevent air or moisture to penetrate through it's protective surface and at the same time, stop the oxidation process (rust) by chemical alteration.

I will say however that mechanically (sanding/sandblasting) removing the rust and then properly prepping and priming would be THE best methos for rust elimnation.
If I were applying POR-15, I would still remove as much rust as possible and then follow manufactureer's instructions.
Eastwood's rust prevention products are also very good and I may recommend them over POR-15.

[This message has been edited by Jimmy P (edited 07-21-2002).]

[This message has been edited by Jimmy P (edited 07-21-2002).]

I'm not a big fan of por. I have used it three times and have not had good result with it no matter how anal I have been about following there instructions. I did a frame off and used the por on my frame, I found that it chips just as easily as anyother paint during reassembly. I currently have a situation where some brake fuild leaked onto a fire wall that was done with por and chasis coat and it it all wrinkeled up just like any other paint would be. I have had much better luck with coreless (sp?) and a top coat of rustoleum. It works as well and doesn't take 12 steps to use. Also it costs a lot less.

just my .02 and personal experience.

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72 Chevelle and a 70 Chevelle with a crushed roof
ACES # 4051 MCC # 448
TC # 1549 81/70 Cruisers

charles,
I like to use POR, but have not used it on sheetmetal that is to be exposed or under a vinyl top... not to say you couldn't try it.

The POR paint goes on like any other, but then there are some differences. First off, it needs to have something to 'bite' into, so the rougher the surface, the better it sticks. Second, the prep has to be done very well, or it won't stick good either. It does react with rust to neutralize it and then seals out moisture. When drying, it likes to have humidity and will dry quicker, the wetter the air. Real dry areas will take a long time to dry. And finally, the POR paints are what they are calling 'closed-cell' paints meaning that once they do dry fully, NOTHING will get through them... even solvents and brake fluid! This is different frm 'normal' paints that are 'open-cell' and will allow 'stuff' to get into them. Where I have seen a lot of problems is that yes, it will chip like regular paint when hit with a sharp object or an edge of a hammer or something, but is really strong at resisting damage by blunt objects. Of course, how many blunt items ever hit the car! Them, if there is a scratch or edge of the POR where solvents or brake fluid can get under them, it will peel like regular paint in no time.

Good luck,
Bill C.


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Bill C.
'71 SS (now with 467BBC)
'70 Nova 350/700r4
ACES #2780
Colo Spgs, CO

Forget the POR and use etching primer followed by regular primer. This is still the best way I feel to do this. The POR needs a rough surface to grab onto, and won't like sheetmetal very well. I would actually paint the top as well. Seems to me that even a vinyl top will allow moisture to bleed through it, while they did not paint the top at the factory that could be why all vinyl top cars have surface rust on their tops.

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Mat Ellison
Lincoln, Ne
70 SS 396 Chevelle
62 Impala Sport Coupe
2001 Grand Prix GT
Aces #2424
http://www.geocities.com/elliboom/Mats_70_Chevelle.html?994781720927

And finally, the POR paints are what they are calling 'closed-cell' paints meaning that once they do dry fully, NOTHING will get through them... even solvents and brake fluid! Bill C.


[/B][/QUOTE]

Sorry, but I disagree with Bill on this. No offense intended but in my experience the stuff is not as good as advertised and it is a pain to work with. I have a section of my cowl that was striped, roughed up, prepped with their prep, washed with water, then coated with por 15 and top coated with their top coating paint. Six months later a mechanic spilled brake fuild down the cowl. Within a few hours the entire area from the master cylinder to the bottom of the cowl was/is wrinkeled like any other paint would be.

Another application I used it on was the base of a basketball pole that developed rust at the base where it went into the concrete. I painted it with the por and top coated it with an oil based paint. The rust came back through within a few weeks. I then wire brushed the pole again and applied a coat of coreless with no top coating and that has been on there almost a year and no sign of rust.

As I said above I used it on the frame of my car. Now, I did not sandblast the frame but I power washed it, wire brushed it, degreased it with an industrial cleaner that they use to clean up tractor trailers. I did not use their prep on the frame or the basketball pole, I admit that. But during assembly of the suspension and when mounting the body we found that the paint was easily removed with your thumbnail. If you hit anything against it it flaked off. By the time the body was in place we had it all knocked up. It does not work well over top of other paints either in my eperience so you have to remove all other finishes. If the por is left exposed to the sunlight for any length of time it turns white/chalky. I also discovered that it is easily removed with finger nail polish remover even after it dries on your skin (wife showed me that one). While it is still wet paint thinners will remove it easily. The stuff does flow on nice with no brush marks and a quart will paint your house.

I know a lot of guys love the stuff, and I'm not vendor bashing. I love the por puddy. That stuff is one of the best things I've ever used. I patched a whole in the crank case on a chain saw with it. I just have not had any personal luck with the por paint product.

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72 Chevelle and a 70 Chevelle with a crushed roof
ACES # 4051 MCC # 448
TC # 1549 81/70 Cruisers

[This message has been edited by Professor_SS (edited 07-23-2002).]

Professor,
No problem on the disagreement... as long as we keep it respectful. I understand your issues from personal experience and have my own as well.

Over the past two years or so, I have done a lot of brake work and suspension work on the Chevelle. One of the first things I did was the B-body spindle swap and while I had everything apart, I went ahead and slapped some POR on the suspension pieces as well as the top and sides of the exposed frame rails. Over the years, the top has been exposed to numerous brake fluid spills and never had a problem. Not too long ago, I had a brake connection that was leaking and I didn't notice it until days later. It had dripped onto the frame rail and rolled down to the bottom and slightly under where there was no POR. It found the edge and from that point, it started wrinking and peeling the paint from the bottom up. It took off the POR about half-way up the side of the frame, but the top still looks good and it probably sat the longest with the POR.

Again, one of the key things I have found is to not leave any edge or scratch exposed or rust/chemicals will get in there and defeat the POR. Also, some of the topcoats do not seal like the real POR paint, so that may have something to do with it also.

Personally, I've had very good success with the POR products and will continue to recommend them except on body panels.

Good luck,
Bill C.

hey no problem Bill, I said lots of guys love the stuff, I just can't seem to get the performance out of it that they claim that's all. Now their puddy stuff, man I love that stuff, filled some holes int eh rear window channel, a small hole at the base of the cowl, couple other things, the stuff is great.....

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72 Chevelle and a 70 Chevelle with a crushed roof
ACES # 4051 MCC # 448
TC # 1549 81/70 Cruisers

I've had nothing but good luck with it. I painted my inner fenders with Por 15 and to this day, they still look like new. I think the problems are encountered in the preparation. For the smooth sheetmetal inner fenders, I first sanded the old paint off and took them to bare metal. Then, and this is where I went away from Por's recommendations, I used a product called Citrus Clean sold by Zep through Home Depot to clean and degrease them instead of Marine Clean. Any good degreaser will do the trick. Next, I used the Metal Ready which is the etching solution. When that stuff had dried, it left a white powdery residue which I cleaned off with a sponge and soap and water. When they were good and dry, I brushed the Por on and it flowed out as though it had been sprayed.

I don't know why some people have not had success with Por 15, but there are a few who can't get the stuff to work for them no matter how careful they are with the preparation. I can offer no explanation. The only thing I can recommend is this; go with whatever product works best for you. If Por 15 works flawlessly, use it. If you have problems, or if you prefer Eastwood's Corroless, go for it. You have to use what works best for you. That's what makes this a hobby. Otherwise, it'd be called work.

Personally, I've had both good and bad results. First time I used it, it worked great. The latest batch has been nothing but a headache. Followed all the instruction steps, but I keep getting "pulls" opening up in the surface.

The only difference this time is the parts have been sandblasted, whereas I wire brushed the others. I've double washed, etched, rinsed etc. the stuff just WON'T work this time. http://www.chevelles.com/forum/rolleyes.gif

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Eric Taylor
72 Malibu 350 (http://www.chevelles.com/showroom/ericsvellepic1.jpg)
68 SS396 basket case