Paint for Underside of Pickup Truck Box

[johndeere123]

The underside of my truck box is starting to rust, and I am looking for a good paint to put on it to stop/slow the rust. I am thinking of painting it with a roll on bed liner to keep the rocks from chipping away the paint. Have any of you tried this? Or should i just go with an epoxy based paint?

 

[Deeretracks]

I would spray it with POR15. The roll on bed liner will only hide the rust while it gets worse underneath. Loctite Extend is a good rust converter too.

 

[Dozerboy]

POR15 isn't all its crack up to be IMO. It sounds like most of the time it isn't lasting much longer then paint. Do you really plan to keep the truck long enough to justify putting this kind of time into it? Rust proofing is kind of a lost cause IMO.

I have been pretty happy with using Plastic Dip spray paint on the fender wells of my truck. Easy prep, and easy to touch up.

 

[johndeere123]

Rustproofing is a necessity here if you plan on having a vehicle reach 10 years old. There is rust started now, and if I want to keep the truck 3 more years without replacing the box, it will be worth the time.

 

[Steve Frazier]

From what I've read about POR-15, it is designed to serve as stop measure for rust and not a topcoat. The instructions state it should be painted after it has cured to ensure longevity. I haven't used it but have been looking at it for use on my truck frame. From my research the number of positive reviews far outweighs the negative.

 

[Multiracer]

http://www.fluid-film.com/

This stuff seems pretty good for what you are searching for.
It is awesome as a battery post sealant. I have been experimenting with an aerosol can... seems like a very good product. Sold in most good farm supply stores.

 

[Deeretracks]

We used to have a fleet of dozers that pushed salt around in the hulls of ships and we used that Fluid film on anything that moved. It worked really good at keeping corrosion down but it was kinda sticky and didn't dry to a hard layer. Not sure I'd want to do a whole underside with it.

 

[Dozerboy]

Rustproofing is a necessity here if you plan on having a vehicle reach 10 years old. There is rust started now, and if I want to keep the truck 3 more years without replacing the box, it will be worth the time.

Same here there is an area of the US called the Rust Belt.

Well it depends on your level of skill. You could pull the bed off get it upside down and touch up all the areas with paint. Or just clean up the rust and clean the paint good then use bed liner or Plastic Dip like I mentioned. The later being cheaper and easier, but bed liner is heavy so depending on how you use your truck that could be an issue. What kind and year of truck is it? GM makes some plastic wheel well liners that will keep the salt spray off the under side of the bed or you can make your own out of some sheets of ABS plastic. Spraying down the undercarriage with and oil like Fluid Film will help too.

Edit: Ha I was a little slow with the FF recommendation.

 

[mikebramel]

We used to have a fleet of dozers that pushed salt around in the hulls of ships and we used that Fluid film on anything that moved. It worked really good at keeping corrosion down but it was kinda sticky and didn't dry to a hard layer. Not sure I'd want to do a whole underside with it.

I spray the Fluid Film AR(industrial gel) every 1-2 years and the areas that were bare and flashing over are no worse than they were 5-6 years ago and never wash the vehicle

 

[johndeere123]

The truck is new to me, and was never undercoated. I spray my vehicles with fluid film every year. The truck is a 2008 F250, I am going to take the box off and flip it so I can do the entire bottom of it as well as the frame. I'm not going to bedliner the frame, just paint on that.

 

[RCTech9]

Post some pictures!

 

[planecrazzzy]

Freak'n tough azz paint

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Someone sent me this the other day... Amazing stuff..

I don't know much about it... But since the subject came up...
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http://www.chonday.com/Videos/paincoatsrong2
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Gotta Fly...
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[johndeere123]

The cross member pictured is the worst one on the box, It is borderline now, but I am hoping to make it last a few for years

 

[Catback]

Top pick looks like rust through. POR 15 is good stuff...it likes rust. I would at least wire wheel most of that off (or blast it if you have access). Then I would clean, apply POR 15, and a POR topcoat, or, wait a few months, then prime and paint with a good industrial enamel or epoxy.