Need advice rust on the frame?

Last I heard was that POR-15 could not be painted over, normal paint would not adhere to it.

 

Ya, I forgot to mention that it will haze over if it is in direct sunlight. The stuff is easy to apply but if it gets on your skin, you will wear it for a few weeks. If you brush it on, it will leave brush strokes when you first apply it. Don't worry about them. Look at it again in 5 minutes and it will be as smooth as a baby's butt.

 

Somebody on here said a long time ago you spray paint over POR before it dries so it sticks.

 

I don't know how you guys use POR-15 but here is what I do with it.

I first clean the surface with a wire brush, then blow it off with air. Then I degrease it, I use a water based degreaser I got from a company I worked for, it works great but expensive. After I let that dry, I hit it with air and then use the metal prep stuff that POR-15 sells, this is the important thing - it stops rust from continuing to form. After that dries, I hit it with the POR-15, after that is all dry, I use a good primer and then hit it with a top coat or color coat.

I've used the stuff since the 80's, the same way and never had problems but with my trucks, I wouldn't even waste my money on POR-15 unless I am doing a restoration (which is not a fixer up thing but a lot of work).

Instead I would hit the frame with either sand (sand blasting or soda blasting low pressure) or a wire brush it (not heavy on either, but just enough to clean the rust up, get rid of the flaking paint and scratch the paint for adhesion). Then I would go and get Rust-Oleum rusty metal primer, hit the frame that is exposed with a couple coats, let it dry completely and then apply a good Rust-Oleum top coat that seals it all in.

This will fix those problems but overall it will continue because of the abuse our trucks get. I have driven 2014 trucks which have rust on their frames from just sitting on the dealer's lot waiting for their upfitting. My '99 FL has a bunch of surface rust but nothing that I am concerned about nor will I go and take the time to buy four gallons of an expensive product to put on there, I just will paint it as I mentioned if I want to clean it up.

 

I don't ever get too impressed by expensive products, but the POR-15 has proved the exception. I also don't get to involved in the prep and have had excellent results. I just use a rattle can of NAPA black after brushing the POR on a clean surface.

 

Prime and paint, never had a problem... Actually the only problem is finding the POR-15 in my area. Due to salting of the roads in MN, the stuff flies off the shelf, in spite of the price around here.

 

black paint and a wire wheel/sandblaster goes a long way. paint is not perfect, but easily repairable, and cheap. if you don't want any more rust after the paint, spray your chassis with old motor oil in a garden sprayer once a month. think how nice the frame looks underneath vehicles with oil leaks! I do this a few times a year on my pickup truck, and it works great. nothing preserves steel like oil and grease!

fwiw, I live in the land of salt and rust, western NY. there are places that offer the oil service, but they use environmentally friendly oil, with lanolin.

 

http://www.kbs-coatings.com/

This stuff looks about like a POR 15 but might be better by reading through everything. I use POR 15 on many things and love the stuff!!! Its holds up very well on the underbody of my pickup even after this past winter we had. I also did the whole floor inside my truck 4 years ago with it and it worked great! As for the frame on a big truck, I would probably do 3 or 4 coats of the stuff and then use a really good paint. At the same time whats it cost to go and have the frame blasted, primer, and paint applied? That might be the better option. I am pretty sure that will be the route that I go this year before winter on mine and then just keep up with it after that with POR 15 under the cab and a rustoleum rattle can on the exposed frame just because its simple and worked well.