Por15 vs Rust Bullet

[snappytravis]

Just curious what the feedback is on these two products. They seem very similar. I also looked at the eastwood ceramic chassis paint. Has anyone used it?

I plan to paint the chassis a semi gloss black and then us a bedliner kit for the floor pans on the bottom of the car. I will be spraying the frame of the car wich is new clean metal and also the underside of the floorpans and part of the floor is new and part is old blasted metal, for the most part I don't really have any rust that I am trying to cover.

[mitch_04]

My decision based on a large amount of reading is epoxy primer. It is durable, soft enough to resist cracking from metal flex and rock chips, can be topcoated with most anything if you want to make it pretty or bedlined, easy to touch up, and inexpensive.

The downsides I've read about POR15 is that it dries very hard, which makes it easier to chip if flexed too much. It also can develop very very thin cracks for the same reason, which allows moisture to get behind it and reek havoc.

I don't have a ton of info on Rust Bullet. I am wary of any product which says it can go over rust. To me it's just the wrong thing to do, definitely the wrong thing to manufacture. It's catering to, generally, lazier people.

You, on the other hand, already have new metal and blasted metal. A quick scuff on the new floor and old blasted floor and you have a great surface for a long lasting finish.

An owner of a paint company ones wrote on a forum that the recipe for POR15 is out for any manufacture to grab, and it is insanely cheap to produce leaving huge profit margins. However, no paint manufactures want it, if that means anything. I'm speaking in generalities, but if you would like specifics PM me and I'll send you to the thread.

Lastly, urethane reducer will lift and crack POR15. That's why you have to buy POR's tie coat if you want to put real paint on top of it.

[snappytravis]

Thanks for the reply, Urethane reducer will lift it. That would tell me that it isn't a catalyzed paint. I am thinking maybe dp epoxy and a semi gloss urethane paint may be the way to go.

[mitch_04]

If I recall correctly it is moisture cured but I could be wrong.

[Dave B]

I coated the underside of my car, seven years ago with POR 15, it still looks like the day I'd did it, I've driven it in some nasty rain storms. I followed their directions, and it worked great for me.
Recently, from what I was told NPD switched from POR to KBS, so I looked into it. A KBS dealer in Ohio told me it was a chemist from POR that started out on his own...I haven't use it, but found it interesting.

[jlcustomz]

Products like por-15 & others are meant to encapsule any remaining rust from moisture, keeping it from spreading. Results vary on how good that works, but they can work great.
If you got clean metal, go with mitch's recommendation of epoxy primer. When done correctly, it's still the all time tested best option.

[Rick Dorion]

I've used both on metal prepped as well as I am able. I had POR15 peel from new floors. It needs tooth to stick. It's also extremely toxic, not that you want to breathe any of these products. Rust Bullet was used on new trunk floors and drop offs and held up fine during the 10 years I had the car.

[bbcmonte]

I like KBS instead of por-15,but I never use rust bullet