automotive rust question

I’ve got a 2005 Dodge Ram 4x4 Laramie with 186,000 km on it. The cab and engine are in great shape, and I’ve kept up with maintenance—new hoses, belts, fluids, and I’ll be replacing the plugs this winter. The frame and cab are solid, but the box is slowly going. The lower fronts are rusted out, and when I checked the wheel wells, I found they were also starting to rot.

Since I only drive about 10,000 km a year, I’m planning to replace the box with a used one and want to get another 10 years out of it.

A new used box is under 3000 and a lot less than spending 70K on a new truck when this run like great.

Question:
Before I install the replacement box, what’s the best way to prevent rust? I’ve heard about different options, like:

• Tar-based coatings
• Bed liner paints
• POR-15 or similar rust treatments
• Other methods

What’s worked best for you guys to keep rust away in rough weather and road conditions? Appreciate any tips or advice!

Amazon sells Krown Rust inhibitor by the gallon jug. It's under $100 and likely as good as any.

Quote:

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Originally Posted by overyonder

I’ve got a 2005 Dodge Ram 4x4 Laramie with 186,000 km on it. The cab and engine are in great shape, and I’ve kept up with maintenance—new hoses, belts, fluids, and I’ll be replacing the plugs this winter. The frame and cab are solid, but the box is slowly going. The lower fronts are rusted out, and when I checked the wheel wells, I found they were also starting to rot.

Since I only drive about 10,000 km a year, I’m planning to replace the box with a used one and want to get another 10 years out of it.

A new used box is under 3000 and a lot less than spending 70K on a new truck when this run like great.

Question:
Before I install the replacement box, what’s the best way to prevent rust? I’ve heard about different options, like:

• Tar-based coatings
• Bed liner paints
• POR-15 or similar rust treatments
• Other methods

What’s worked best for you guys to keep rust away in rough weather and road conditions? Appreciate any tips or advice!

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After putting a ton of effort into rust proofing my Chevy from New spraying with "corrosion free 3000" myself because after the first professional job I could see they didn't put much effort in. I still have the rear fender lips bubbling at 6 years old. I found that sand and debris would sit on the inside lips of the fenders and that's where the rust starts. Keeping an eye on and touching up paint chips and anywhere the fender liners rub I think are the most important. I would definitely put some kind of vinyl film or protection anywhere the wheels throw dirt and also install mud flaps.

There's no rust at all on the cab so I assume the product I use is doing the job where the paint is still intact.

Frequent car washes, especially in winter months, works well to keep salt away.

Corrosion Free is by far the best, tests done by US and CDN military put it far ahead of others like Fluid Film and Krown. And the nice thing, it does not drip all over the driveway or garage.

Parking a vehicle inside a garage that holds moisture is very bad.
Spray inside hoods and doors with oily rustproof. Coat inside fender and box underneath with a thicker oil.

A coating that dries hard like bed liner paints can hold moisture in and rust the metal under the paint if the surface is not prepared properly. Commercial rust spray products that stay liquid and spreads over time was tested a few years ago by university students to be the best, the disadvantage is it needs re-application at least once a year.

Quote:

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Originally Posted by Fisherman

Corrosion Free is by far the best, tests done by US and CDN military put it far ahead of others like Fluid Film and Krown. And the nice thing, it does not drip all over the driveway or garage.

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FluidFilm works great - it's a natural base - lanolin. I'm not a fan of any rust proofing that hardens in place.

I lease my vehicles so rust isn't my problem... lol

Thanks everyone I am probably go with either Fluid film or Por 15, I will have to figure out a way to scuff it first underneath. Maybe a job for the Son's to do.

I rarely drive it in the winter only when I really need it like if the wife needs my car cause hers is in the shop. The rest of the winter it is in the shop keeping warm.

Good chance I can drive this easily for another 10 years.

Quote:

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Originally Posted by Marker

A coating that dries hard like bed liner paints can hold moisture in and rust the metal under the paint if the surface is not prepared properly. Commercial rust spray products that stay liquid and spreads over time was tested a few years ago by university students to be the best, the disadvantage is it needs re-application at least once a year.

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Corrosion free is good for a year and a half so you get three years of product for the price of two.

Another vote for fluid film. I've had my truck Krowned for a few years but after having access to a buddies hoist it looks like they've missed areas. I bought a Woolwax gun with all the attachments and buy the Black Fluid Film from Princess Auto. It goes on nice and heavy yet the overspray creeps into the nooks and crannies. I have a 2012 Silverado and removed the box to replace the fuel pump and not only did all the bolts come out easy the underneath and frame is in great shape.