Slow down rust?

Hi all...I have a 3/4 ton Chevy (1987) truck that I'm fixing up for a plow truck...to use on my private road. I have the engine out for repair right now. Is there anything I can spray/or brush on the frame...underside of engine compartment...etc...to slow down the rusting so I can get as much time as I can from the truck frame etc? Your ideas would be great. OldMainer

Por15 makes a rust converter that I'v seen good results out of. There is also rust converters that they sell at auto parts stores real cheep that usually arnt worth shit.

krown makes some good rust preventing products. my family uses that and so does the mechanic i work for.

I've used the POR 15 with great success. My friend swears by Eastwood's Rust Encapsulator product. Make sure in either case that the frame is spotless of grease. Steam cleaning it is about the only way, and even then I'd back it up with some hot soapy water. It is paint, so it won't stick to the metal if its not perfect

Auto Restorer magazine did a test of Por 15 along side Eastwood's Rust Encapulator and they prefered the latter. I have tried both and agree. Here's a link to the article.

http://www.eastwoodco.com/jump.jsp?itemID=852&itemType=CATEGORY&iMainCat=688&iSubCat=852

I like those products listed above, but wet salty winter road spray can and does overcome those products over time.............its happened to me........... if something quick, cheap and dirty is required, try this:

I have had great success using a professional-grade oil underspray product, that I get in 4 liter jugs. When sprayed on it has the consistency of motor oil, but has a solvent in it that evaporates, so it sets up a bit thicker than gear oil. Over time, dust/dirt sticks to it forming a messy but very effective greasy layer.

Just be sure to scrape or brush off the worst of the loose/flaking rust first.

A pump-up garden type sprayer with a wand does fine for the application, and can get into pretty tight places.

I have also sprayed on an ATF/gear oil blend that does much the same thing.

Just reapply it every fall. It usually takes me 30 minutes to thoroughly treat the underside of my truck.

I have heard of old timers doing the same thing you advise except they were using used motor oil. Just what is this "professional-grade oil underspray product" you mention? Either way it sounds so messy that I haven't considered trying it yet. Do you have any other tips for application without making or leaving a big mess? I believe these guys were allowing the vehicle to drip over some cardboard sheets after oil application. My driveway is too nice to have a car dripping oil all over it for days. Thanks.