Is POR-15 a good undercoat rust preventiong sealer?

 

I thought it was expensive and time consuming, but was impressed with the way it turned out. I liked how if you are really lazy about it you can just paint it on over the rust.
Granted, we don't really have rust here. I see unrestored '70s beaters all the time with no rust on them. I bet in NE it would be a great, but expensive, under body coating.

 

I had good luck with their stuff. Picked up a couple of their starter kits to do up a 9-bolt rear I had bought for my last car. Just follow the directions and you'll be happy with the results. But don't get it on your skin; I had a spot the size of a half dollar on my leg for a month because I dropped the axle tube on my leg while it was still wet.

 

I swear by POR-15. The only thing I dont use it on is stuff that gets exposed to direct sunlight. POR-15 doesnt stand up to UV rays, and needs to be top coated if you are going to have it exposed.

But on axles housings, crossmembers, brackets, floors, SFCs, etc....its fantastic. Things that I painted with it years ago still wipe clean and look like powder coat. And my car gets driven. Salty roads, wet roads, whatever.

To me, thats the best part about that stuff. You can brush it on with reckless abandon and it'll lay flat when it starts to cure. Its the closest thing to "brush on powder coat" that I can think of. That and you dont have to do a whole lot of prep for it to stick and work as advertised.

It is expensive...but you get what you pay for in this game.

J.

 

It is the best well known rust preventer. It doesn't come off, as long as it's not applied to flaking rust. Be careful handling it though, and don't drip it on anywhere you don't want it to go. Works great for battery trays.

 

Is Por-15 just brush on or can it be sprayed through a paint gun? if so can it be thinned down, does it use a special gun, or can it be sprayed though a siphon feed or gravity feed gun?

 

It can be sprayed, but it's not recommended as vapors are extremelly toxic. Imagine that stuff in your lungs...

 

From their site:

"Most people brush it on, but many spray also. Proper equipment and organic vapor particulate respirators for solvents are essential for spraying. "

"You should use only POR-15 Solvent for thinning. Keep lacquer thinner handy for clean-up. Do not thin POR-15 more than 5%."

Ive given thought to spraying. However, given that this stuff bonds to just about everything it touches, the thought of it becoming airborn sort of scares me haha. Besides, it lays so flat after brushing that I never saw the need to spray.

J.

EDIT: This is one quick coat on my crossmember. Completely dry. Some fish eyes, but I did hardly any prep to the bare clean metal. Just some brake cleaner to degrease it. I went back and did a second coat, but this is how it turns out when it dries in most cases. I just lathered it on too...didnt exactly take my time.

 

Thanks guy for the heads up, I Like using Rustoleum and spaying it, I've never used Por-15 thinking about trying it out. do they offer any other colors than black?

 

You just made me want to go buy some. I hope Napa has it...

 

The only place, besides online, that Ive found it is at my local auto body supply shop. Place is called Kayfield. Im not sure if NAPA has it, but they surprise me sometimes with the stuff they happen to have.

Couple words of advice for this stuff. Since its so expensive, you DEFINATELY dont want to use a little, and have the rest go bad. So take extra care in sealing the can back up. You really do have to put some wax paper or saran wrap under the lid. If you let the excess paint cure, you wont get the lid back off. Go ahead and use as much of it as you can... Sort of like powder coating. You usually wait until you have all of your powdercoat stuff ready before going to the coater. Ive already ahd two cans get hard and become useless because I couldnt use all of it See if some friends want to use some and go halfies or something.

J.

 

How much POR-15 do you think is neccessary to do the underside/floor pans of the car?

 

Napa did have it, but in black they only had 4 ounce and 1 gallon cans. 4 oz. isn't enough, but a gallon is $160...
They said they would order a pint for me. I just need enough to do under hood, whole underside of car, and wheel wells.

 

$160 isnt bad for a gallon. I think I pay like 30-40 bucks for a pint. Or is it a quart... I cant remember. A little bit of that stuff goes a long way though. It sticks, covers, and bonds really good.

Ide love to coat the whole underside of my car with it. But in order for me to have the patience for that, the car would have to be stripped and put on a rotisserie. Im not interested in laying under my car cleaning all the crud and undercoating off these days. I would like to clean my wheel wells out though...

J.

 

Yea I hear you. Sometimes we gotta do what we gotta do.

Since this POR-15 is sparking my interest. What would be needed to properly prep up the underside of the car for por-15? Also, how much por-15 would be needed for the underside??

 

I used it from the front subframe area just were the firewall curves under the car to just after the floorpan curves back up for the rearend and gas tank, and on my rearend. iusered the starter kit which comes with a pre cleaner and a zinc treatment. the kit comes with a 4 oz can and almost everything you need to do it. just need to sand any rough areas and make sure there is no loose rust. I think i used 5 or 6 4 oz cans for this. I plan on doing the rest of the under side someday but no clue when. right now i just want to enjoy the car as it sat for 5 years In my garage plus i need new quaters and paint so i will probably just finish it when i get the money to do that.

 

I love the stuff but only use it on areas that already have rust, it kind of reacts to it (the rust). On something that is rust free there are better things to undercoat with IMHO.