©By: John T. Blair (WA4OHZ)
dot_clear 1133 Chatmoss Dr., Va. Beach, Va. 23464; (757) 495-8229

Last updated: Jan. 21, 2000

1. What is POR-15 paint?
POR-15 is a polyurethane paint that contains a rust inhibitor. It can be painted over light rust and will stop the rust for spreading. It dries pretty much rock hard and is very scratch resistant. It seals the metal and is used as a primer which can be lightly sanded and painted over with another primer or a color coat. It will fill in small (pin) holes. The stuff is great any place that you'd expect to get rust.

It is moisture cured. The higher the humidity the faster it drys.

2. How is it applied?
It can be brushed or sprayed. However, for most areas, I suggest brushing. It will gum up a spray gun. I purchased an undercoating gun from JC Whitney for $35 that I use to spray the POR-15 in places (like the quarter panels from inside the trunk) that I can't reach with a paint brush. It flows pretty well. (Note: 2009 I don't see the undercoating gun at JCWhitney's.)

If you plan on spraying it, do so only if you are wearing a forced-fresh-air respirator. It contains Polyisocynates and is nothing to fool around with, but the results are worth the precautions.

3. Can it be used as a top coat?
No! While POR-15 does flow out nicely and dries to a nice high gloss, it has a tendency to generate tiny bumps as though the paint were out gassing which is noticeable on smooth metal. However on items like chassis or rusty metal that are rough any way the bumps aren't very noticeable.

The only disadvantage is it is Gloss Black, but the color will flush out if exposed to UV (sunlight). Consequently, any POR-15 that will be exposed to Sun light should have a top coat of some other paint applied. It makes a great "chassis" paint as the chassis is not exposed to sunlight.

4. Is this like a asphalt based paint or undercoating?
No, it isn't.

5. How should metal be prepared before painting?
It is best to sand blast the metal. This is especially true for "new" metal. POR-15 needs something to bite into. Old rusty metal can be cleaned by using a wire brush. By this I mean a knotted wire wheel on a 4" 10,000 rpm grinder.

6. How do you store it?
I save all my cherry and olive jars and tops. You want relatively small jars about 2" in dia. and maybe 3" tall. When the quart of POR-15 is first opened, pour it into several of these small jars and place a piece of plastic or wax paper over the top of the jar then put the top back on. If you don't put the plastic on, the top will stick to the jar and you can't get it open. I've also found that if you store the jar upside down it helps. Especially any that are not totally full. The POR-15 is activated by humidity and the air that is trapped in the jar will cause the top surface to harden. You can cut down through it to get to good paint. But by storing the jars upside down, the film will be at the bottom so when you open the jar, you have paint! [Just check that the tops and plastic are on tightly. I've had one jar leak all over my bench. I don't recommend using jars with plastic tops if you plan on storing them upside down.]

I've also found that it has a much longer shelf life if you store it in the refrigerator. [Hint: Not you your wife's refrig in the kitchen. And don't store it upside down in there.]

7. How do you use POR-15?
When you want to use POR-15, open a storage jar and pour a little into a plastic cup, (I salvaged small butter tubs from the kitchen). Then immediately reseal the storage jar.

A little POR-15 goes a long ways. It's easier to go back for more than to have a lot of it go bad. It will "flash", start to harden, and not be spreadable much like body putty fiberglass resin, or epoxy.

Depending on the humidity, the life of the paint in an open container, (butter tub) is about 1/2 hour (at least here in Southern VA. when the humidity is between 95 and 106%).

Do not return any unused portions to the storage jar after you have had it out. This will contaminate the paint in the jar and cause it to harden. So take the leftovers and paint your ramps, inside your bumpers, rusty steel wheels.

Since you aren't opening 1 big jar all the time, the POR-15 lasts a lot longer. At worst I only through a little away when I get to the bottom of the jar. Before I started doing this, I have had to through about 1/2 a quart away - $20 down the drain.

8. How do you stay clean?
I purchase the loose fitting plastic gloves from a warehouse buying club (Price Club/CostCo). I get 3 packs of 100 gloves for about $5. I where these when ever I'm using the POR-15 or a acid metal etchant. While I don't stay completely clean, it's a lot better than not wearing the gloves.

While the paint is still wet, you can wipe it off using a rag and lacquer thinner.

9. What type of bristle brush do you use?
I buy the cheapest 1" brushes I can get, about 75 cents each, from Kmart. When I finish painting, I pour any remaining money (I mean POR-15) into the garbage can on top of old paper. Then I clean the butter tub and paint brush with lacquer thinner or acetone. I get indefinite use from the butter tubs (10 or more uses) and at least 3 uses from 1 brush.

But then again, I'm cheap.

BTW if you aren't aware of it, you can purchase a 5 gal. of **cleaning** grade lacquer thinner for $18-$25. That is quite a savings since I just paid $18/gal for lacquer thinner to paint with.

10. Is there an acceptable way to thin POR-15?
Yes. POR sells a solvent that you can used to cut the POR-15 with. However, you can only cut it about 20%. I've found that if I am brushing it on, I don't need to cut the POR-15. So you can save you money.

11. Where can I get POR-15?
The POR company. They advertise in Hemmings all the time. Their address is:
POR-15 Inc
P.O. Box 1235
Morristown, NJ. 07962-1235
(201) 887-1999
(800) 457-6715 To email POR-15 Company with comments or questions.

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