The frame and bed-floor on my '79 is swiss-cheese, and knowing it was going to be awhile before I could do anything about it, I wanted to at least keep it from getting worse.

With the bed off, cab on, I cleaned off the loose rust and oil & garbage, sprayed one side with Right Stuff a couple times and painted the everything from the cab back with a brush-on of Rustoleum's Rusty Metal Primer. I probably should have left a piece un-primed and Right Stuff only, and another Right Stuff and finish-painted, but I didn't.

The truck's been (mostly) sitting for 1 1/2 year now. I looked at it the other day and I didn't see any indications of further rusting -- no bleed-throughs, no bubbling, existant holes don't seem any worse.

I have my doubts that it would stand up to daily-driving -- I don't believe the Rustoleum or iron phosphate is all that resistant to rock-chips.

 

I'm glad I found this post. I have some serious rust on my frame and just about everwhere I look under my truck. My son had it up in Wisconsin for 10 years before I got it. I know I am going to have to pull the bed off to get to most of it but I was not sure what to use. Now someone had told me about a product called rust encapsulator by Eastwood www.eastwood.com Has anyone used this product? I really only want to have to scape and treat this rust problem one time if I can get away with it.

 

Since you want to do it only once, have it blasted and powder coated. I personally wouldn't recommend POS 15 as everything I painted with it has slight rust dots forming. I prepped it similarly to the stuff I did with rustoleum, but the rustoleum parts aren't rusting yet. Oh, and rustoleum is about 1/3 to 1/4 the cost of POR 15.

 

I am curious about how good rustoleum works because there isn't a lot of detail from rustoleum themselves or much on the internet. I have been working on painting my 1998 Ford Explorer underside for over a year now. It takes a lot of time because of so many nooks and crannies. I hope this works otherwise this was a big waste of time and money, but these are the results so far:

The rustoleum really looks good when used over the old worn out paint on the top of the car. It will protect from future rust really well when sprayed over something that isn't rusty yet. The paint repels water.

I made a mistake also thinking that all rustoleum is the same. They have slightly cheaper paint that is only for decoration. The rust will come right through this paint and it does nothing but good for appearances only. So you must buy the paint that says "stops rust" on the can.

The truck is in good shape. Only slight rust in places on the underside. There were a few small places with somewhat heavy rust.

The primer alone will protect against extremely light rust. For the most part if you just prime it the rust will bleed through over time though in some places that are very light the primer alone protects. The regular paint by itself actually stops rust better than primer by itself, but the primer takes moisture out of the rust so is good to use as a base.

If you prime it and put a layer or two of "stops rust" paint on the top (I used black, white and blue) the rust does not seem to bleed through, the paint looks good and all seems well. We will see in the future how it turns out. The paint that says "stops rust" has fish oil in it which repels water and prevents rust.

In some places I have used two layers of rusty metal primer and a couple layers of paint. Obviously I brush away and wipe off any rust as best as I can. I just try to do as much as it takes where rust doesn't bleed through. Usually it takes about three or four months for it to bleed through if it is going to do so.

The somewhat heavier rusted parts will bleed through despite layers of rust primer and paint. This requires many layers of paint to control and really I should have put rust reformer over it first.

I'm sure sooner or later the rust will return but I think the rustoleum could really extend the life of the metal for many years to come. Only time will tell.

It seems to me the smartest move to do would be to paint rustoleum over surfaces BEFORE it rusts. This way the metal could last basically forever. The Rustoleum will keep it from rusting really well and probably last for 10 or 20 years before needing painted again. Once it starts to rust in any major way that's when you have to worry if it is still rusting under the paint and will it eventually bleed through etc.

There is definitely a big difference between a "stops rust" paint and regular spray paint. The regular spray paint will do nothing to stop rust. Even if you paint it on non-rusty metal the metal will rust just the same as if it were never painted. So you have to use the paint with the fish oil or whatever is in it to repel water and rust.