BlackTop at a Glance
500°F
Heat Resistance (liquid sizes)
5H
Pencil Hardness at 96 hrs
2,000 hrs
Salt Spray Over RustSeal
Protection & Durability
- Moisture-cured urethane resin: BlackTop cures from moisture in the air into a hard, flexible film.
- Permanent UV stability: BlackTop does not chalk or fade in the sun.
- Rock hard, yet flexible: BlackTop expands and contracts with the metal underneath.
- Salt spray tested: 1,000 hours alone, 2,000 hours over RustSeal.
- High heat resistance: 500°F on liquid sizes, 300°F for the aerosol.
Versatile Application
- Bonds to clean metal: ferrous and non-ferrous surfaces.
- Bonds to coatings: painted, primed, or RustSeal-sealed surfaces.
- Brush, roller, or sprayer: BlackTop flows out and self-levels.
- Aerosol available: in all three sheens for small parts and touch-ups.
Available Finishes:
Gloss Black 85 to 95%
OEM Satin Black 55 to 65%
Flat Black 15 to 20%
Best Results: Seal the metal with
RustSeal first, then topcoat with BlackTop. Two coats of RustSeal under one coat of BlackTop reach 2,000 hours of salt spray resistance, twice what BlackTop reaches alone.
BlackTop is a single component moisture-cured urethane, so BlackTop needs no hardener, no mixing ratio, and no separate clear coat. BlackTop cures to 5H pencil hardness, resists 500°F on liquid sizes, and holds permanent UV stability, so a BlackTop finish on a frame or trailer does not chalk or fade in the sun.
- Single component (1K): open, stir, and apply. There is nothing to mix in and no pot life to beat.
- Single stage: the color coat is the final coat, with no clear coat on top.
- Moisture-cured urethane: durability, flexibility, corrosion prevention, and chemical resistance in one film.
- Permanent UV stability: the black stays black outdoors.
- Rock hard yet flexible: the film moves with the metal instead of cracking.
- High heat resistance: 500°F on liquid sizes, 300°F for the aerosol.
- Brush, roller, or sprayer: BlackTop flows out and self-levels.
- Aerosol option: the BlackTop aerosol uses a professional-grade acrylic lacquer resin for strong adhesion and color retention.
- Shelf life: about 2 years unopened and about 6 months after opening when stored cool and dry per the directions.
A utility trailer frame sealed with RustSeal and topcoated with BlackTop.
Which BlackTop Sheen Should You Choose?
BlackTop Gloss Black measures 85 to 95% gloss and reads as a wet, reflective show finish. BlackTop OEM Satin Black measures 55 to 65% and matches the semi-gloss look most factory chassis and suspension parts left the plant with. BlackTop Flat Black measures 15 to 20% for a non-reflective finish that hides surface imperfections. All three sheens share the same resin and the same durability data.
BlackTop is used on automotive and truck chassis, frames, suspension components, engine compartments, firewalls, floor pans, wheels, and bumpers, and on utility, boat, and car trailers. BlackTop is also the right choice for exterior black trim and chrome-delete parts that sit in direct sun, plus wrought iron railings and fire escapes.
Automotive & Truck Chassis
Car & Truck Frames
Car Bumpers & Trim
Chrome Delete
Engine Compartments
Engine Firewall
Suspension Components
Floor Pans & Trunks
Wheels & Rims
Dump Trucks
Car & Boat Trailers
Utility Trailers
Wrought Iron Railings
Fire Escapes
One gallon of BlackTop covers roughly 400 square feet at 2 mils dry film thickness, a quart covers about 100 square feet, and a pint covers about 50 square feet. A BlackTop aerosol covers roughly 38 square feet. Expect up to 50% less coverage on bare wood and on rough, coarse, or sandblasted surfaces.
Theoretical coverage at 2 mils dry film thickness is 400 sq. ft. per gallon. Material losses during mixing and application will vary.
| Container Size | Coverage at 2 Mils DFT |
|---|
| Aerosol | 38 sq. ft. |
| 8oz (Half Pint) | 25 sq. ft. |
| Pint (16oz) | 50 sq. ft. |
| Quart (32oz) | 100 sq. ft. |
| Gallon (128oz) | 400 sq. ft. |
| 5 Gallon Pail (640oz) | 2,000 sq. ft. |
BlackTop alone is the shorter-term option for clean, non-rusted bare steel, while RustSeal under BlackTop is the longest-lasting KBS chassis system. Two coats of RustSeal under one coat of BlackTop reach 2,000 hours of B117 salt spray, twice the 1,000 hours BlackTop reaches alone, and RustSeal is required once any rust is present.
| | BlackTop Alone | KBS Klean, RustBlast, RustSeal, then BlackTop |
|---|
| Salt spray (B117) | 1,000 hrs at 4 to 5 mils DFT | 2,000 hrs at 4 to 5 mils DFT total |
| Rusted metal | Not suitable | Yes, RustBlast and RustSeal treat and seal the rust |
| Surface prep | Clean with KBS Klean, then apply | Clean, etch with RustBlast, seal with RustSeal |
| Topcoat timing | Not applicable | BlackTop goes on RustSeal that is 3 to 8 hours old with no sanding |
| UV stable black finish | Yes | Yes, BlackTop protects the RustSeal from sun fade |
| Coats | 1 to 2 coats of BlackTop | 2 coats of RustSeal, 1 coat of BlackTop |
BlackTop alone is the better choice when the steel is new or freshly blasted, clean, and free of rust, and the job needs a durable black finish quickly with fewer steps.
Buying for a full frame? The Chassis Paint Kit packages RustSeal and BlackTop together.
BlackTop is applied to clean, dry surfaces by brush, roller, or spray gun at 55 to 82°F in 70% relative humidity or lower. Stir BlackTop thoroughly rather than shaking it, apply one or two covering coats at 2 mils each for automotive work, recoat once the previous coat is dry to the touch and before 24 hours, and allow 48 hours for full cure.
Surface Prep Before BlackTop
Clean the surface with KBS Klean rather than a solvent-based cleaner, because solvent cleaners leave an invisible residue that affects BlackTop adhesion. Where there is rust, treat it with RustBlast and seal it with RustSeal first. Freshly applied RustSeal between 3 and 8 hours old needs no further prep and can be topcoated directly. Any other painted surface should be scuffed with 320 grit, then cleaned and dried, or given a light dust coat of Fusion Self-Etch Primer.
Mixing, Thinning, and Recoating
Do not shake or whip BlackTop. Stir thoroughly with a KBS Hurricane Paint Mixer or a stir stick, touching the bottom of the can and lifting to bring settled pigments and matting agents back into suspension. Pour a working amount into a separate container rather than painting out of the can. If heat or humidity is causing brush marks to hold, thin BlackTop 5 to 10% with KBS #1 Thinner or xylene, never lacquer thinner. Recoat once the previous coat is dry to the touch and leaves no fingerprint, and before 24 hours have passed. Past 24 hours, scuff the cured coat with 320 grit or a green Scotch-Brite pad first. Full cure is 48 hours.
Brushing and Rolling BlackTop
Brush or roll an area with BlackTop and move on rather than working the brush back and forth. Overworking BlackTop forces the solvent out, and the brush marks then cannot flow out the way BlackTop is designed to. Apply one or two covering coats at 2 mils each for general automotive work, and a minimum of two coats for marine or industrial work.
Spraying BlackTop
Thinning is not generally required for spray, but 5 to 10% with KBS #1 Thinner or xylene is normally adequate. Strain through a 100 micron filter and use an air line dryer filter. HVLP runs 25 to 35 psi air and 25 to 35 psi fluid with a 1.0 to 1.6mm tip; conventional spray runs 35 to 55 psi air and 15 to 20 psi fluid. Full settings for every gun type are on the paint spraying guidelines page. Clean the gun immediately after use.
Cleanup and Storage
Clean up BlackTop with KBS #1 Thinner before BlackTop dries. Once BlackTop is cured, no solvent will remove it. Never pour unused BlackTop back into the can, because it shortens shelf life and can build pressure and pop the lid. Keep the can groove clean with a KBS Paint Spout, lay painters plastic between the lid and the can to stop metal-to-metal contact, and spray KBS Paint Saver into the can before sealing for storage.
ALWAYS WORK IN A WELL-VENTILATED AREA. A NIOSH/MSHA approved air supplied respirator is recommended. Always wear
protective gloves and eyewear when applying BlackTop.
Aerosol quick reference
- Spray at 60 to 78°F, 70% humidity or lower
- Shake at least one minute after the ball rattles
- Hold the can 6 to 8 inches from the surface
- Shake 10 seconds every 1 to 2 minutes while spraying
- Invert and spray 4 seconds after use to clear the valve
Applying the Satin sheen: BlackTop is heavily pigmented, so the matting agents must be fully back in suspension before you start. Apply thin coats only. For an even flatter finish, reduce BlackTop 20% with KBS #1 Thinner or xylene.
BlackTop is 62.5% volume solids and weighs 8.72 lbs per gallon. BlackTop reaches 5H pencil hardness at 96 hours, absorbs 160 inch-pounds of direct and indirect impact, and rates Excellent against 10% sodium hydroxide. BlackTop alone passes 1,000 hours of B117 salt spray at 4 to 5 mils, and 2,000 hours over two coats of RustSeal.
| Physical Property | Value |
|---|
| Volume Solids | 62.5 ± 2.0% |
| Weight Solids | 67.8 ± 2.0% |
| Weight Per Gallon | 8.72 ± 0.5 lbs/gal (varies by sheen) |
| Viscosity | 27 to 33 sec #2 Zahn cup |
| QUV 313B | 1,000 hours |
| Durability Test | Result |
|---|
| Pencil Hardness | 5H at 96 hours (aerosol 2H) |
| 10% Sodium Hydroxide | Excellent |
| Impact (Direct/Indirect) | 160 inch-pounds |
| Salt Spray B117, BlackTop alone | 1,000 hrs at 4 to 5 mils DFT |
| Salt Spray B117, RustSeal (2 coats) plus BlackTop (1 coat) | 2,000 hrs at 4 to 5 mils DFT |
Have questions before you buy? Find answers to the most common BlackTop and chassis paint questions below, or
order BlackTop now.
The best black chassis paint bonds to clean metal, stays hard but flexible as the frame flexes, resists road salt, and holds its color in the sun. KBS BlackTop is a single stage, moisture-cured 1K urethane that does all four: 5H pencil hardness, 1,000 hours of B117 salt spray on its own and 2,000 hours over RustSeal, and permanent UV stability, so BlackTop does not chalk or fade outdoors.
The best paint system for a chassis is a rust-sealing base coat under a hard, flexible, UV stable topcoat. KBS BlackTop is that topcoat: a one-part moisture-cured urethane with no hardener to mix and no clear coat to apply. For the longest life, seal the metal with two coats of RustSeal first and topcoat with BlackTop, which reaches 2,000 hours of B117 salt spray.
For the underbody, a rust-sealing coating comes first, because the underbody sees water, salt, and stone chips. The KBS underbody system is KBS Klean to clean, RustBlast to treat rust, and two coats of RustSeal to seal the metal, with BlackTop on top wherever a UV stable black finish is wanted. Cavity Coater goes into frame rails and enclosed sections last, after the exterior coatings have fully cured.
Chassis black paint is a durable black topcoat made for vehicle frames, suspension parts, and trailers, usually in the semi-gloss look factory chassis parts came with. KBS BlackTop is a chassis black paint made from single stage, moisture-cured 1K urethane, available in Gloss Black (85 to 95% gloss), OEM Satin Black (55 to 65%), and Flat Black (15 to 20%).
On clean, non-rusted bare steel, BlackTop can go directly on the metal after cleaning with KBS Klean, and BlackTop will adhere. That is the shorter-term option. For the longest-lasting protection, and whenever any rust is present, use the full system: KBS Klean, RustBlast, two coats of RustSeal, then BlackTop. Two coats of RustSeal under one coat of BlackTop pass 2,000 hours of B117 salt spray, versus 1,000 hours for BlackTop alone.
Recoat BlackTop once the previous coat is dry to the touch and leaves no fingerprint, and before 24 hours have passed. If more than 24 hours go by, lightly scuff the cured coat with 320 grit paper or a green Scotch-Brite pad before recoating. Full cure for BlackTop is 48 hours and depends on time, temperature, and film build.
Ideal BlackTop application temperature is 55 to 82°F for brush, roller, and spray gun, and 60 to 78°F for the aerosol. Apply BlackTop in moderate to dry conditions, meaning 70% relative humidity or lower. In elevated heat and humidity BlackTop cures too quickly and brush marks may not flow out, which is corrected by thinning BlackTop 5 to 10% with KBS #1 Thinner.
Gloss Black is the choice for a wet, reflective show finish. OEM Satin Black is the choice for a factory-correct chassis, since its 55 to 65% gloss matches the semi-gloss look most frames and suspension parts left the plant with. Flat Black is the choice for a non-reflective finish that hides surface imperfections. All three sheens share the same resin and durability data, and KBS offers a free painted-out sheen sample to compare them first.
Yes. RustSeal that is between 3 and 8 hours old can be topcoated with BlackTop directly, with no sanding and no other prep. Outside that window, and on any other painted surface, lightly sand with 320 grit paper, then clean and dry the surface before applying BlackTop. A light dust coat of Fusion Self-Etch Primer, allowed to dry, is an alternative to sanding.
Clean brushes, rollers, and spray guns with KBS #1 Thinner immediately, before BlackTop dries. Once BlackTop has cured, no solvent will remove it. Never pour unused BlackTop back into the can. Keep the can groove free of paint with a KBS Paint Spout, lay painters plastic between the lid and the can, spray KBS Paint Saver into the can before sealing, and store in a cool, dry place. Unopened BlackTop lasts about 2 years; opened cans typically last about 6 months.
