How many coats of POR15?

[Beck180]

While waiting for my subframe to come back from powder coating, I thought it would be a good chance to do some rust prevention.

Cleaned the frame rails and painted with POR15. I've done two coats now just cause the first coat looked a little thin after it dried.

How many coats should I do with POR15?

Thanks!

[gastephens]

What did products / method you use to clean the underside?

Remember regular POR is not UV resistant. Even though very little light gets to the underside of the car, you still need to top coat with a plain old black paint or use POR UV resistant top coat.

[Beck180]

What did products / method you use to clean the underside?

Ground down with a wire circular brush and then used compressed air to get all the remnants off. Did I do it wrong?

Remember regular POR is not UV resistant. Even though very little light gets to the underside of the car, you still need to top coat with a plain old black paint or use POR UV resistant top coat.

Wasn't planning on top coating. So just some basic black paint would work?

[Harv]

POR sells chasis black. Works great over por 15. It's black with a hint of green.

John

[stricht8]

Ground down with a wire circular brush and then used compressed air to get all the remnants off. Did I do it wrong?

You kinda did it wrong. It is always prudent to follow their instructions to a Tee. After grinding away loose rust, you should clean the area with Marine clean followed by their metal prep. If painting over bare metal, you need to "season" the metal for better adhesion. Again follow their directions, marine clean followed by the metal prep. The metal prep will season the metal. POR15 dries very shiny. You must either scuff the surface prior to topcoating, use another one of their paints that ties in the topcoat or lightly mist a primer over an almost dry ( just slightly tacky) por15 followed by a topcoat.

[jmr_1602]

I followed the POR-15 starter kit instructions. Used the Marine Clean first, followed by the Metal prep. Then I applied three coats of POR-15 (though on the can they only mentioned two.)

I was unaware of adding a top coat however. Glad I saw this thread.

[JackF]

When I did the floor pans on the 72 I got in a hurry and didn't exactly follow the instruction for POR. A couple days later I grabbed a loose corner and most of the paint came off like a piece of Saran wrap. Started over, followed the instructions nad ended up with a great finish. I did two coats. +1 on the Chassis Black.

[Stacey]

I think using a metal conditioner prior to putting the 1st coat on is probably more important than the number of coats, but I'd say 2 is a minimum. As a side note, I found if you timed it just right, you can spray a finish coat over POR15 just as it flashes and get a pretty good bond with a top coat. If you wait too long though, it will not bond and can peel off. Too early and it bubbles up as the POR15 is curing.

[Beck180]

Again follow their directions, marine clean followed by the metal prep.

Ah damn. And he I was thinking I was cool and done. I guess it's another trip to the paint store.