underbody coating?


Founding Member
Apr 2, 2001
Rockwall, TX
I coated the top of my new floor today with POR-15, and I'm wondering how would be the best way to coat the underbody. I could do POR-15 on it as well, but it seems like it would be a huge messy hassle laying on the floor dripping that stuff all over myself. Is there another good way you guys would recommend to coat it? I've used rubberized undercoating before, but I don't think that stuff is very good at preventing rust on its own. I also bought a quart of epoxy primer to do my quarter panels, but my spraying setup isn't ideal (tiny compressor, no booth, no filter/dryer) so I'm having doubts about spraying any more than I really have to. What would you do?
  • Sponsors (?)

I did the por15 on my back thing.

I`m not sure I did mine right but here goes...

I first sprayed the underside with rattle can etching primer.

Then laid on my back and used por15 and paint brush, got it all over me of course, and 2 weeks later the last of the por15 finally fell off me.

It seemed that the primer gave the por15 something to grab ahold of, it looks pretty good, people that have looked at it cant beleive I used a brush.
I scraped all the old undercoating and grease of, scrubbed the metal with degreaser, powerwashed, coated with the Metal Ready from POR and then I did my Por15 with foam brushes. I wore double long sleeve shirts and long chemical type rubber gloves.

Wear eye protection, and coat your face with some lotion. Then work from one side to the other. You will be real supprise when a big drip smacks you in face to minutes after you brush over an area. I dries, sooo slow, but looks so cool. I took a pic just so I could say I did it right. http://i48.photobucket.com/albums/f210/68converted/Underside.jpg

I wanted a "bit" of sound proofing, so I then sprayed the underside with 8 cans of rubberized undercoating. :D

Good luck
Did the same.

Cleaned, degreased, painted it POR 15 via brush on my back, then did a top coat of Semi-Gloss to protect it.

Two weeks, you got lucky. It took a month to get that POR 15 off my skin. :D
As was stated earlier, MAKE SURE YOU USE THE METAL-READY!!! Make sure the metal is absolutely clean first, then soak with the metal-ready. And yes, completely cover anything and everything you don't want coated, it doesn't last forever on unprepared surfaces, but if sure does last a long time. If you are going to topcoat the POR 15 with something else, do it before the POR completely cures or you will have to use their primer over it, just another step you could avoid.
Being that my car was being built more as a driver than a show car, I went with coating the entire car with a marine based primer called InterZinc 52. The seams were then sealed and then I pput two kits of truck bed liner on the underside of the body and two kits on the inside. Now it is really tough and you can barely get a drill bit to scratch it. Attached are a couple of pics: