I am looking for some feedback on what is the best to use to protect the under side of the box and cab from corrosion. I am restoring my 1979 Ford F150 and live in South Dakota and would like to know what material(s) people have experience with. I want to do this only once and do it right.

 

I am just getting ready to do the same thing to the fenders and cab of my sons 1977 i am going to use rust-oleum diy bed liner with the spray cans and with the roll on quart container

 

I am a firm believer in Ziebart!! I have had several trucks and bronco's done over the years and take them back every year for FREE undercoating applications. But I have also done a few on my own and I highly recommend SEM Low Voc rubberized undercoating (#40523). It comes in spray cans and the application is very easy and seems to give great protection against rust!

 

I can certainly endorse the Ziebart process. My 1976 F350 supercab was treated in Virginia Beach, VA in the summer of 1976, a couple of months after I took delivery of the truck. The undercoating is still intact throughout the bottom of the truck. I had the interior cavities--doors, kick panels and the pillor cavities--treated at the same time. Although it has always been garaged, there is no rust anywhere that I've been able to find. I have several of the little yellow Ziebart plugs scattered around the cab and doors where they drilled to spray in the treatment to remind me of having had it done. I was not aware that they offered annual free re-treatment of the bottom. If I can find a dealer in NVA, I'll see if they will do it for me.

 

Ive been into auto body collision and restoration over 30 yrs,(im retired now) i wouldnt under coat anything if your gonna drive it threw the winter/salt. Im not going to get into a pissing match but ive fixed and have replaced frames due to under coating, it dry's cracks and salt will get in there and sit,then rot. Ive lived in Mich. all my life and never have had a rusty car/truck, i use a cheap paint gun and spray my old motor oil up under,inside,across and into every hole and it will never rust.

 

Yep. Going to throw gas on the fire too. I have nothing negative to say about the ziebart stuff I have no experience with it. However cheap out of a can bed liner and undercoating I do. Stay away from the stuff. If you don't spray with oil as above consider a comercial spray on bed liner. The spray on bed liners about the only coating I've seen that would be tough enough to stand up to sprayed wheel well rocks.

 

I fairly recently treated the underside of my mostly survivor '78. Suggestions 1) clean it very well... solvent and a stiff brush on grease/oil, strong detergent (eg simple green) and pressure washer or better yet steam cleaner. 2) Remove any loose paint or rust with wire wheel on light metal or needle peen frame and heavy gauge metal. 3) Prime with rust stop primer. Red Rustoleum and Eastwood rust encapslator work well in my experience... I'm sure others can work as well. 4) Paint 5) Post paint treatment should include waxy RP in hidden areas like rockers 6) Post paint treatment may include coating the entire underside with solvent thinned oil/grease... I haven't done this but believe it helps if done well.

I use the bedliner material in the bed... not underneath. Undercoating in areas subject to rock chips like fendes but not elsewhere (after prep mentioned above). The thick coatings have drawbacks as mentioned in threads above (cracks and rust creep). Also hard to maintain later.

 

Fertilizer sprayer and old motor oil, works for the Hutterites and Mennonites, I grew up in southern Manitoba, 12 miles north of the U.S border. I also use spray on rocker guard but that's mostly to save me bodywork detailing and it makes people go ooh aah and makes it easier to sell vehicles.

 

Set up an undercarriage "bird bath" on your driveway... hook up two sprinklers like pictured below and park over them. Irrigate for one minute. Done.

 

Subscribed.

I live in Yankton and a couple weeks ago brought home a rust free truck from Oregon. I am worried what the next winter will do to it. I'm going to try Fluid Film on it until I am ready to restore.

 

My experience with a sprray on rubberized undercoating is it don't last. Sprayed a couple cans of the expensive professional Duplicolor undercoat on the frame and bed supports of my 04' daily driver last year when I had to replace the brake backing plates. I also painted a 10" long section with two coats of Rustbullet to see how it does.

This winter was a cold winter with a decent amount of smaller snows which ended up with a lot of salt water spray ans salt on the road. The supports and frame sections with the undercoat on it is all rusted up at spots. The Rustbullet spot has no rust at all. I also did several spots at my doors before winter with Rustbullet and those spots did not rust either.

I used the silver automotive rustbullet as a first coat and then one or two coats of black as an overcoat. I am going to ordered 2 more gallons of the Rustbullet this spring to use and see how it does over the next few years. It looks promising.

Also truck bet coating don't work for rust prevention either. Stripped a set of running boards down to bare steel, put a base coat of paint and then coated with roll on truck bed coating. The running boards looked good before winter came. After winter they rusted all to hell.

My 74' F-100 has the Ziebart coating inside and out which I believe got done when it was new. There are holes drilled all over the truck where the coating was sprayed in and then plugged with yellow plastic ziebart plugs. The coating has been peeling off but it did help to prevent rust. However when I boat the truck over 15 years ago it was obvious the truck was in a garage most of its life and may not have ever been out in winter. I drove it as a daily driver in all weather conditions for about 5 years but I washed the thing all the time including the underside.