I am about to do some sort of under truck rust prevention but I am undecided which route to go. I live in Ont. Canada where they use Salt on the roads like the crap is going out of style!!
I was thinking about cleaning the frame and then painting it with some sort of top quality black rust paint or something along the lines of high heat paint. Afterward I was going to get the dripless oil spray and voila... I would be done..? But I wanted to see what else is recommended or not......

 

Sounds like you're planning on doing a lot of work. There are several products out there that might do a decent undercoating job and POR15 is one of them. Here's their site: http://www.por15.com/

 

Because we use evaporative cooling here in the southwest they sell stuff called "submarine paint" in the hardware stores to coat the inside of our coolers. Stuff will dry as hard as a rock and as long as there isn't any rust already it will do a good job of rust proofing.

 

I saw give her a heavy coat of oil every fall.. any pain coating that don't seep into the rust will not stop the rust.. in fact it helps it.. The oil will keep seeping and seeping and stop the rust dead...

Messy, but worth it..

 

How do you do an underside anti-corrosion oil coating, and what kind of oil should I use? Thanks for any info. 'best, Lou

 

So you don't think I should paint it before getting it undersprayed with dripless oil? It would make it look a little cleaner.

Loudawg...not sure if you have a local Ziebart or Krown rust check. Best bet is take it there when they have their specials on something like $75 here in Ont. Make sure you have done all the work you need to underneath before you get this done. You won't want to work under there for awhile...2-3months...

 

I had a Tacoma from upstate NY that had rust on the frame. I wanted to slow/stop the rust and thought about doing this. I researched a lot about oil coating a frame and rust prevention. Old timers would take oil from an oil change, put it in a sprayer, and coat the bottom of their cars. This was also done with diesel and kerosene. It seems everyone now said don't do this as it may make the rust worse. The oil would mix with the salt/water to create acids. Old oil formulations didn't do this. There is lots of info on the net about rust prevention and the old oil tricks. I would have a place like Ziebart spray the whole thing. I sand blasted all the spots on my truck and sprayed undercoating on. A LOT of work.

 

Thanks for the ideas folks. Our problem here is the use of mag-chloride slime on the roads, which is not as corrosive as salt, but still bad stuff for long-term vehical ownership. We don't have any rust proofing companies that I know of, and simply spraying a temporary coating of some sort might be good enough, hence my quesitons about doing it home-brew style. The best info I've found out so far is to use chainsaw bar oil and spray the underside of the truck with that, along with frequent washing and re-application when necessary.

More thoughts and comments appreciated.

'best, Lou