Best Truck Frame Paints: Protect Your Chassis from the Elements

Protect the undercarriage of your vehicle from rust and weather with these top truck frame paints

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The undercarriage of your truck is exposed to dirt, road salt, and all types of elements on a regular basis. This can quickly lead to surface rusting and corrosion. There are a range of chassis paints and undercoatings with rust preventive options that can protect your chassis from damage for years to come. Have a look at our top picks to see what’s available.

  • Best Overall
    POR-15 Rust Preventive Paint
    Summary
    Summary
    A lead-free, rust preventive coating for any bare metal surface with a rock-hard, non-porous finish to lock out moisture. No need for prep work or sandblasting, so you can get the job done quickly and easily.
    Pros
    Pros
    This paint is available in different colors, including silver and gloss black, so you can match your truck. It comes in various sizes, so you only buy what you need. It’s easy to apply, and a little goes a long way. Its rock-hard finish protects for a long time.
    Cons
    Cons
    This frame paint will lose luster if regularly exposed to UV light, so a topcoat may be required in some areas of the truck. It’s also difficult to remove stains and spills from skin and fabric.
  • Best Value
    Fluid Film Rust and Corrosion Prevention Undercoating
    Summary
    Summary
    A non-toxic alternative to regular truck frame paint that protects your truck in an environmentally friendly way. Made from lanolin and petroleum oil to repel water, it contains no solvents, so it won’t dry out.
    Pros
    Pros
    A gallon of this undercoating is considerably cheaper than traditional rust preventive paints, providing a viable and affordable alternative if you need to protect your chassis quickly and cheaply. It also dries clear, so you don’t have to worry about color matching.
    Cons
    Cons
    This undercoating is not a permanent chassis paint and needs to be reapplied at least once a year.
    While the smell is less offensive than the alternatives, it will take a while before it disappears.
  • Honorable Mention
    Plastikote Gloss Black Chassis and Grille Guard Paint
    Summary
    Summary
    Hard-wearing and scratch-resistant, this versatile spray paint in gloss black is suitable for use on both internal and external metal or wood. It’s UV- and water-resistant, so it won’t fade or yellow over time.
    Pros
    Pros
    Available as a spray paint for convenience and ease of application. It provides great coverage and does not require any prep work, although removal of surface rust, if present, will result in a better finish.
    Cons
    Cons
    The small size of the can means it’s unlikely to cover your whole undercarriage, so it’s more suited for touch-ups and scratch repair. No other sizes or colors are available.

Tips

  • Punch two holes (one for pouring and one for ventilation) in the lid of the truck paint. Decant some into a container for immediate use, and put the rest into a jar with a screw-top lid. Coat the top of the jar in petroleum jelly to keep it airtight and easily accessible the next time you need it.
  • Take every safety precaution when painting your truck with a rust-preventive coating. The fumes are highly toxic, and the paint should only be used in well-ventilated areas. The paint itself is designed not to come off whatever it bonds to, including you.
  • Whichever paint you choose, make sure it’s VOC compliant across all states. The lower its VOC level, the less harmful its fumes are to you and the environment.

FAQs

Q: Can I use truck frame paint in a spray gun?

A: While it should be possible to apply most rust preventive paints using a spray gun, it’s best to check the manufacturer’s recommendations. A wax-based undercoating may need to be warmed up before it can be sprayed efficiently.

Q: Can I paint over the truck frame and underbody paint?

A: Yes, although it’s important to wait until the paint is fully dry before adding a topcoat. And while prep work isn’t vital, we recommend a quick scuff sanding to improve adhesion.

Q: Do I have to prepare the frame of my truck before painting it?

A: It’s important to check the instructions on the paint can. While it’s not necessary in most cases, sanding and cleaning the area with a wire brush will often result in a much smoother finish.

Final Thoughts

For a long-term solution to surface rust prevention, POR-15 Rust Preventive Paint is the best overall truck frame paint.

Our best value pick, the Fluid Film Rust and Corrosion Prevention Undercoating, is a much cheaper, more environmentally-friendly alternative.