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10 Best Undercoatings for Trucks 2020 – Reviews & Top Picks

3M-Professional-Grade-Rubberized-Undercoating-03584-16-oz

Winter weather can wreak havoc on the undercarriage of your truck. Moisture corrodes and rusts every metal surface and connection beneath your vehicle. Salt from the roads adds to the corrosion, and worse, creates abrasions, scratches, and chips all over your truck’s underbelly. More than just dirty and unattractive, this leads to premature wear that can cause excess expenses down the road.

When looking for a solution to this all too common problem, we discovered spray-on undercoats that can protect your vehicle’s undercarriage while improving its look and longevity. Some created nice finishes while others just protected. Certain brands protect against scratches and abrasions while others just provide safety from moisture and corrosion.

To help you decide which one is right for you, we’ve tried as many we could find. After testing them all on our own vehicles, we’ve written up the following ten reviews to compare our findings. After reading, you’ll be ready to pick the perfect protective coating for the undercarriage of your truck.

A Quick Comparison of our Favorites

Image Product Details
Best Overall
Winner
3M 03584 Professional Grade 3M 03584 Professional Grade
  • No drips or runs
  • Protects against corrosion
  • Protects against chipping
  • Best Value
    Second place
    Rusfre RUS-1020F6 Rusfre RUS-1020F6
  • Gallon size
  • Great adhesion
  • Affordably priced
  • Premium Choice
    Third place
    Dynatron 544 Dyna-Pro Dynatron 544 Dyna-Pro
  • Can be painted over
  • Can be brushed on
  • Super-thick rubberized coating
  • Fluid Film 13 Fluid Film 13
  • Lubricates
  • Stretches a long way
  • Superior rust and corrosion protection
  • Rust-Oleum 248656 Rust-Oleum 248656
  • Extremely affordable
  • Quick-drying formula
  • Sound-deadening properties
  • The 10 Best Undercoatings for Trucks – Reviews 2020

    1. 3M Professional Grade Rubberized Undercoating – Best Overall

    3M-03584-Professional-1

    For the best mix of quality, protection, and easy application, the 3M Professional Grade Rubberized Coating is a clear winner and our top recommendation. The no-run formula makes it easy to get a clean finish that looks nice, even if you’ve never sprayed paint like this before. Aside from looking nice though, this undercoating provides excellent performance. First, it’s great for protecting your undercarriage, wheel wells, engine compartment, etc. It can help prevent scratches, chips, abrasion, rust, corrosion, and protect against all forms of moisture and weather.

    If that’s not enough, it also has sound dampening properties that allow it to absorb vibration, reducing the sound you hear in the cabin. This can help to reduce road noise drastically and a feature we appreciated about the 3M undercoating. Despite being such a great performer, it’s not perfect. The one glaring weakness we noticed is that a single can will not to get you very far. Granted, each can isn’t terribly expensive. But if you plan to do the entire undercarriage of your truck, expect to go through quite a few cans. We can overlook this slight drawback for the excellent protection and performance.

    Pros
    • No drips or runs
    • Helps reduce road noise and vibration
    • Protects against corrosion and rust
    • Protects against chipping and abrasion
    Cons
    • Doing a whole undercarriage will take 10+ cans

    2. Rusfre Automotive Rubberized Undercoating – Best Value

    Rusfre-RUS-1020F6-1

    Unlike our top pick that came in an aerosol spray can, the Rusfre automotive rubberized undercoating comes in a large gallon container for increased coverage. In our testing, it still took several gallons to coat the entire undercarriage, but it was much more cost-effective than using loads of spray cans. You’ll get much better coverage and more even application by using a paint sprayer than any aerosol could ever deliver. So, you will also need a separate spray gun, which can be expensive if you don’t own one already.

    Luckily, the Rusfre undercoating packs in performance at an affordable price, which is why we think it’s the best undercoating for trucks for the money. It had excellent adhesion and stuck perfectly to every metal surface it touched. On the downside, it took several days for this undercoating to dry enough to drive the truck again. Expect your vehicle to be garage-ridden for a few days after applying. The finish looked good once applied and freshened the underside of the truck. Overall, we think it’s the best value, which is why it’s earned second place.

    Pros
    • Gallon size for increased coverage
    • Great adhesion to metal surfaces
    • Affordably priced
    • 2-4 gallons should do an undercarriage
    • Nice finish
    Cons
    • Requires separate paint sprayer
    • Extended drying time of several days

    3. Dynatron Dyna-Pro Rubberized Undercoating – Premium Choice

    Dynatron-544-Dyna-Pro-1

    The Dynatron Dyna-Pro rubberized undercoating from 3M was an impressive formula that checked off all the boxes. It comes in 1-gallon and 5-gallon containers for maximum coverage. We found that this product covered the most area per gallon compared to other undercoats we tested. Even better, the Dyna-Pro was a very thick, rubberized coating that seemed to offer the best protection of any formula. This product protects against, abrasion, scratches, chipping, weathering, moisture, rust, corrosion, and more. It’s an all-in-one solution for refreshing and protecting your truck’s undercarriage.

    The Dyna-Pro had a nice black finish that looked great once it dried. If you prefer a different look, it can be easily painted over. Generally, we prefer spraying our undercoating to get an even application and to reach all the nooks and crannies. This formula can also be applied by brush though in case you don’t have a paint sprayer and don’t want to invest in one. All the great performance of this 3M product comes at a high cost. This is one of the most expensive undercoats we tried, but the excellent coverage helps to mitigate the cost.

    Pros
    • Protects against chipping, weathering, and corrosion
    • Can be painted over
    • Can be brushed on
    • Super-thick rubberized coating is very durable
    Cons
    • Wildly expensive

    4. Fluid Film 13 Anti Rust Coating Undercoating

    Fluid-Film-13-Anti-Rust-Coating-1

    For excellent rust and corrosion protection, the Fluid Film anti-rust undercoating is a penetrant and lubricant that doesn’t dry out thanks to its solvent-free makeup. Unlike many other products we tested, this one isn’t black, it’s more of a clear amber coating. It didn’t provide the same impact and abrasion protection of the more durable coatings. That said, the Fluid Film undercoating is one of the most effective formulas for protecting against weather, salt, moisture, corrosion, and rust. It can also be used as a penetrating lube for breaking out rusty bolts.

    Compared to similar products, the Fluid Film gallon stretches a long way. In fact, it got the best overall coverage of any undercoating we applied. This is especially great when you consider the high price of a gallon since this isn’t one of the cheaper coatings. While we appreciated the great weather protection, we prefer the coatings that have an appealing finish on top of the protection they offer. For this reason, the Fluid Film anti-rust undercoating will just miss making our top-three.

    Pros
    • Penetrates to the base of all metals
    • Provides superior rust and corrosion protection
    • Lubricates and breaks up corrosion
    • Stretches a long way
    Cons
    • Doesn’t have a nice black finish like others
    • Very expensive gallon

    5. Rust-Oleum Automotive Rubberized Undercoating

    Rust-Oleum-248656-Automotive-1

    Aerosol cans provide an easy method of undercoating application that requires no extra tools or steps. The Rust-Oleum rubberized undercoating is an aerosol spray that makes it quick and painless to protect the underside of your truck. It’s extremely affordable at about half the price of the 3M aerosol can in our top position. But it didn’t provide the same level of coverage, requiring many cans and several coats to get proper coverage. Luckily, it dries very quickly, which allowed us to do our coats in quick succession. Unfortunately, the adhesion wasn’t the best, requiring ample prep of each surface to guarantee it sticks.

    The rust protection offered by the Rust-Oleum spray is excellent. We love the sound deadening properties of this spray as advertised, but in testing, we experienced minimal reduction of road noise and vibration. The black finish is attractive and looks good peeking out from under our wheel wells. Harsh chemical fumes overpowered us in the garage. We’d recommend applying this outside only since the chemical fumes are so intense.

    Pros
    • Extremely affordable
    • Great rust protection
    • The nice black finish looks good
    • Quick-drying formula
    • Sound-deadening properties
    Cons
    • Lots of chemical fumes
    • Requires excessive prep for good adhesion
    • Will require many cans for the whole undercarriage

    6. Penray 4424 Rubberized Undercoat

    Penray-4424-Rubberized-Undercoat

    The Penray 4424 is an affordable rubberized undercoat in an easy to apply aerosol can. It dries to a nice black finish that can easily be painted over. Unlike some other products we tested, this one includes thermal protection. This makes it useful for coating your firewall and reducing heat in the cabin, on top of the other protective uses such as the undercarriage and wheel wells. It’s advertised as sound-deadening and is supposed to absorb vibration to reduce road noise. In our experience, the Penray spray didn’t really perform in this area and the road noise didn’t seem any quieter after applying. That said, it definitely provided great anti-moisture and corrosion protection, which is what we’re looking for.

    We had two main complaints with the Penray rubberized undercoat. First, it’s supposed to be quick-drying, though it took over 24 hours to dry for us. This may be because we had to apply multiple coats, far more than with other products, which is our second complaint. With one coat we just didn’t get enough coverage to be satisfactory.

    Pros
    • Nice black finish can be painted over
    • Sound-deadening
    • Thermal protection
    Cons
    • Did not reduce noise as advertised
    • Required many coats for good coverage
    • Took much longer to dry than expected

    7. Bondo 737 Rubberized Undercoat Aerosol

    Bondo-Rubberized-Undercoating

    Bondo is a well-known and respected name in the auto body industry, so we expected good things from their 737 rubberized aerosol undercoat spray. Right off the bat, it’s far more expensive than similar competitors, though we didn’t notice many extra features for the price. The one standout trait we appreciated was the Bondo spray allows for a one-coat build-up. This means you can make a single coat very thick to avoid drying time between multiple coats. With other products, this would lead to runs, drips, and a messy finish. With this spray, you can build-up one layer to be thick enough to provide the desired protection.

    When applying the Bondo spray, we noticed it did not adhere as well as other undercoats. After having some issues with peeling, we took prep to another level. Once everything was sanded, scrubbed, and thoroughly cleaned, we had no issues with this spray sticking. However, other products didn’t give us such difficulty, and the increased prep took several hours to complete. We’d recommend a spray that has better adhesion so you don’t have any headaches to deal with.

    Pros
    • Allows one-coat build-up
    • Textured hard finish resists chipping and abrasion
    Cons
    • Did not adhere as well as other products
    • Required excessive prep

    8. Evercoat 1348 Premium Rubberized Undercoating

    Evercoat-1348-Low-VOC-Premium-Rubberized-Undercoating

    This aerosol spray rubberized undercoating from Evercoat is completely VOC compliant and gave off far fewer odors than other aerosol sprays we tested. Even better, this one helped reduce road noise once we had thoroughly coated the entire undercarriage and the wheel wells. It dried to a very durable but flexible surface where it stuck properly. Anywhere the prep wasn’t perfect, the Evercoat failed to adhere. We had to take all metal surfaces down to the bare metal to hope for good adhesion.

    Once we got a good coat applied, the drying time was unbelievable. It took several days for it to dry completely, much longer than most of the other aerosol products we tested. But the worst issue is with aging products. The first can we received did not stick well and refused to dry even after many days. A call to the manufacturer confirmed that the paint was outdated. This meant we had to remove everything and start over. In the end, this is a failure we couldn’t get past, which is why the Evercoat spray won’t climb past the eighth position on our list.

    Pros
    • VOC compliant – low odor
    • Reduces road noise
    Cons
    • Excessive drying times
    • Must get down to bare metal for adhesion
    • The product fails if it is old

    9. TRANSTAR Quick Dry Rubberized Undercoating

    TRANSTAR-4363-F

    The TRANSTAR rubberized coating was very affordable, though we aren’t very familiar with the company. Unfortunately, the low price was our favorite thing about this spray. It’s advertised as VOC compliant, but it still exhibited harsh odors that were worse than most products we tried. This spray is advertised as being able to deaden sound, but the road noise remained unchanged in our test truck. Worse, the spray coating came out unevenly, which made it difficult to get a good-looking finish. Altogether, we didn’t think the TRANSTAR spray was as durable and reliable as the other products we tested.

    Pros
    • Affordably priced
    Cons
    • Did not reduce sound as advertised
    • Didn’t provide an even coating
    • Harsh odors despite VOC compliance

    10. Permatex Rubberized Undercoating

    Permatex-81833-12PK

    Permatex is a brand we are quite familiar with, so we were disappointed when the poor performance of their rubberized undercoating was only good enough to earn the final spot on our top ten list. It is one of the most affordable options we tested. Moreover, it dried to a very tough coating that provides adequate protection. Once applied, it took several days to dry, which we have a hard time looking past. Worse yet, the spray pattern is all over the place, creating way too much overspray and leaving you a major mess to clean up.

    Some aerosol sprays had trouble sticking to surfaces that weren’t perfectly prepped, and the Permatex spray was no different. To make matters worse, the formula is extremely runny. This results in a mess of drips and runs that doesn’t look good. It’s also a huge pain to clean up all the mess after. In the end, we can’t recommend this product when many better undercoats are available at similar prices.

    Pros
    • One of the most affordable options
    • Very tough coating provides adequate protection
    Cons
    • Several days drying time
    • Terrible spray pattern makes extra mess
    • Requires extra prep for good adhesion
    • Very runny formula is hard to work with

    Conclusion

    All of these products provide excellent protection for the underside of your truck. However, what they protect against, how well they protect, and how easily they apply vary drastically between formulas. After reading our reviews, you’re probably ready to go get the undercoating that best fits your budget and start hitting your undercarriage. Before you do, we’re going to summarize our findings so they’re fresh in your mind. The 3M Professional Grade Rubberized Undercoating was our tip pick and favorite overall. The aerosol spray is easy and quick to apply with no drips or runs. It offers excellent protection against rust, corrosion, chipping, scratching, and abrasion and even has sound dampening properties to reduce road noise.

    For the best value, it’s hard to beat the Rusfre Automotive Rubberized Undercoating. It comes in gallon containers for maximum coverage, has excellent adhesion to metal surfaces, dries to a beautiful matte black finish, all for a very affordable investment. If price is of no consequence, we recommend the Dynatron Dyna-Pro Rubberized Undercoating as our premium choice. More than just providing superior protection against chipping, weathering, and corrosion, it’s also very attractive, durable, can be applied by brush, and can be painted over.

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