How much rust can under-body spray stop?

[Luke'sScreenName]

So my 2003 F250 is not going to pass inspection this year with frame rot among other things :thumbdown:. I'll have to replace it with another used 3/4 ton truck ASAP.

My plan had been to wait another year and import a very lightly used truck from Down South and then religiously undercoat it. That is not an option now and will have to look locally. My budget will also likely dictate a 4-8 year old truck. Around here that means some rust will already be present.

My question is how much rust can be halted without extensive prep work or even disassembly first? I'll go to a professional place to get it done. Before I moved Up North 6yrs ago I thought I knew what rust was. I had no clue how quickly it can eat a vehicle up!

 

[Tomtint]

It's depressing that a 11 year old truck is rotted to the point where it is NFG. .. The chemicals that are being used on the roads are simply brutal. On both cars as well as the roads themselves

 

[CalG]

So my 2003 F250 is not going to pass inspection this year with frame rot among other things :thumbdown:. I'll have to replace it with another used 3/4 ton truck ASAP.

My plan had been to wait another year and import a very lightly used truck from Down South and then religiously undercoat it. That is not an option now and will have to look locally. My budget will also likely dictate a 4-8 year old truck. Around here that means some rust will already be present.

My question is how much rust can be halted without extensive prep work or even disassembly first? I'll go to a professional place to get it done. Before I moved Up North 6yrs ago I thought I knew what rust was. I had no clue how quickly it can eat a vehicle up!

Those sprays can't do much to stop rust. Oil undercoating every year can slow rust down some, but you need to do a good job every year.

I used to use a mix of linseed oil and bar &chain applied with a syphon sprayer wand. Messy!
This fluid film stuff is showing up on all the counters lately. I've put down about $100 bucks worth on three different vehicles. I spray everything that's showing rust whenever "I'm under there" ;=) The FF doesn't seem to stay long on exposed surfaces.

I'm going back to the B&C oil this coming fall.

 

[WilliamBos]

I get mine sprayed at Krown Rust control every year. Get it sprayed during the hot summer months so it can soak in. It helps big-time.

 

[carmedic310]

To answer the question there is nothing you can do to actually stop rust on a used vehicle.You can slow it down.Years ago rusty jones and ziebart offered undercoating guarantee's neither one is still around because of rust claims.Now there is a company selling a product called fluid film.I do not know much about this new product.There was (not sure if its still out there)a company selling an electronic system where you apply 2 patches one front one rear on your vehicle(has to be put on bare metal) and run wires from the patches to a controler.It is supposed to stop rust by keeping a low votage electical charge to the steel in your car.Theory is it takes moisture and air for rust and this was supposed to keep the air out.I have only seen 2 vehicles in my area with these and both still rusted.Up here in Maine they use calcium chloride on the roads in the winter.I have had to replace brake lines and or fuel lines on some vehicles 4 years old

 

[Tomtint]

I think we need to be pro active up here with rust, and try to stop it before it starts.

 

[Egon]

It takes a lot of work for rust delay/prevention.

A brief description of what I have done. Pressure wash the undersides. Maybe even twice. Use a sand blaster on any rusted supports etc. Stay clear of the frame an coated underside sheets. Wash again. Several coats of phosphoric acid. Spray paint twice. And for the finish mix roofing tar and kerosene and apply to the underside using the vacuum tube and pistol of the sand blaster. Do not worry about getting it on too thick. Oh, you should wear coveralls, very old boots, air mask if it fits under a full sandblast hood. Be prepared to turf any clothes and live outside for a few days.

Twenty year old truck that supposedly rusted out fifteen years ago. The frame and most of the sheet metal is good. The fender wells will need work this spring.ee

the exterior paint has not fared well though.

 

[coobie]

I get mine sprayed at Krown Rust control every year. Get it sprayed during the hot summer months so it can soak in. It helps big-time.

+1 one on the Krown.From my research great rust proofing.I just had my 2016 dodge Ram sprayed with Krown time will tell if it was the correct choice.

 

[the old grind]

Salt has been taking heat for decades for what CaCl does to our cars/trucks year 'round. (NaCl is hygroscopic above ~78% humidity but CaCl is above ~20% humidity.

Ziebart was cakey and flakey, didn't stay on well. Rusty Jones was waxy & stayed on better.

I bought the FF u/coat kit with deluxe sprayer. That said, had I known how reasonably priced the Krown treatment is I would have opted for it instead. (gettin' too old to crawl under stuff ..)

Krown claims similar features/benefits of FF, so might be similar (meant as a compliment, btw, and thanks for turning us on to this promising product.) I did check it out. :thumbsup: (Might get away with bi-annual vs yearly touch-up if you're cheap like me.)

Stopping rust is one thing, making it look good after treatment perhaps a whole 'nother battle.

 

[MossRoad]

Try this stuff and let us know how it works...

Stop Rust with POR-15® - We Know What Permanent Means!

I have a rusty truck I'd like to try it on, but I want some other guinea pigs to try it first.