What is the Large Frame Coater Kit?
The Large Frame Coater Kit is an all-inclusive 3-step rust prevention system that cleans, etches, and permanently seals up to 100 square feet of rusted or bare metal with two coats of RustSeal. The kit contains a quart of KBS Klean, a gallon of RustBlast, and two quarts of RustSeal in any of 11 colors, sized for a full car or truck underbody.
100 Sq. Ft.
Two-Coat Coverage
11 Colors
Non-Porous RustSeal
The KBS 3-Step System pairs RustSeal, a rust preventive coating, with KBS Klean, an industrial strength water-based cleaner and degreaser, and RustBlast, a powerful rust remover and metal etch. Used in sequence, the three products handle contamination, active rust, and long-term sealing rather than covering a problem that keeps growing underneath.
RustSeal chemically bonds to bare metal and forms a permanent, moisture resistant finish that stays flexible and will not crack, chip, or peel. RustSeal is moisture cured, so exposure to humidity makes the film harder rather than softer. RustSeal also resists acids, alkalis, salts, abrasive materials, fertilizers, coal dusts, solvents, oils, and other refined petroleum products.
Buying the Large Frame Coater Kit costs less than buying KBS Klean, RustBlast, and two quarts of RustSeal separately, and the brushes, gloves, stir stick, and printed instructions are included. Satisfaction guaranteed!
RustSeal: Durability and Flexibility Test
The Large Frame Coater Kit contains one quart of KBS Klean, one gallon of RustBlast, and two quarts of RustSeal in the color or colors of your choice, plus durable nitrile gloves, two brushes, a stir stick, and complete printed instructions. Every consumable needed to finish a 100 square foot area is in the box.
- Quart of KBS Klean — industrial strength water-based cleaner and degreaser. Strips oil, grease, and road film so the etch and the coating bond to metal instead of contamination.
- Gallon of RustBlast — rust remover and metal etch in one step. Dissolves surface rust and leaves a zinc phosphate coating that gives RustSeal a mechanical grip.
- Two Quarts of RustSeal — the rust encapsulating topcoat, available in any of 11 non-porous colors. Two quarts is enough for two coats over 100 square feet.
- Durable Nitrile Gloves — RustSeal does not come off skin easily, so gloves are included rather than sold separately.
- Two Brushes — natural bristle brushes sized for frame rails, floor pans, and suspension components.
- Stir Stick — RustSeal must be stirred, never shaken, because shaking whips air into a moisture-cured coating.
- Complete and Detailed Instructions — printed step-by-step directions for all three products.
Can I Choose Two Different RustSeal Colors?
Yes. The Large Frame Coater Kit ships with two separate quarts of RustSeal and each quart is selected independently at checkout, so you can run Gloss Black on the frame and Silver or Galvanized on suspension parts from the same kit. Some RustSeal colors are only offered in select container sizes, so confirm availability on the RustSeal color guide.
Not sure which color to use? See the RustSeal color guide. Some colors are available only in select sizes.
RustSeal is a single component moisture-curing coating that goes directly over treated rust, cures to a completely non-porous film, and needs no topcoat, hardener, or mixing. RustSeal is rated to 500°F, shows zero change after 1,000 hours of salt spray testing, and stretches 79 percent before failing, so it flexes with a frame instead of cracking off it.
- Goes Directly Over Treated Rust: After RustBlast, tight remaining rust does not need to be blasted or ground away. RustSeal encapsulates it and cuts off the oxygen and moisture that feed it.
- Single Component Formula: No hardener, no activator, no pot-life clock. Open the can, stir, and apply.
- High Solids Content: RustSeal is 72 to 76 percent solids depending on color, so more of what you brush on stays on the metal as film build.
- Moisture Cured: RustSeal pulls atmospheric moisture in to cure and gets stronger with repeated exposure to it, which is the opposite of how a conventional enamel behaves.
- Completely Non-Porous: Porosity tests to NACE TM0174 read 0.00 across the entire color range, forming a permanent barrier against moisture and oxygen.
- Eleven Non-Porous Colors: Gloss Black, Satin Black, Silver, Grey, Off-White, Oxide Red, Safety Green, Cat Yellow, Safety Blue, Safety Yellow, and Galvanized.
- Chemical and Abrasion Resistant: Repels fuels, oils, most acids and alkalis, and graffiti, with zero weight loss after 1,000 abrasion cycles under a 1 kg load.
- Flexible, Will Not Crack or Peel: A 79 percent elongation rate lets the film expand and contract with the substrate through thermal cycling from -30°F to 140°F.
- Compatible, Compliant, Lead-Free: Accepts urethanes, epoxies, enamels, lacquers, and two-component automotive refinish topcoats. VOC compliant, lead-free, and mold and mildew resistant.
The Large Frame Coater Kit works on rusted and bare steel, cast iron, aluminum, fiberglass, and properly prepped concrete. Typical jobs include full frames and chassis, floor pans, wheel wells, suspension parts, boat trailers, bilges, farm and shop equipment, and structural steel. The only automotive area to avoid is the exhaust system.
- Automotive
- Chassis, frame rails, floor pans, wheel wells, fenders, trunks, engines, suspension parts, axles, roof drains, springs, and doors. Almost every part on a car except the exhaust.
- Marine
- Engine rooms, hulls, masts, bilges, heat exchangers, decks, chain lockers, pumps, fuel tanks, and boat trailers.
- Industrial and Agricultural
- Heavy transport, steam pipes, sealing concrete, air conditioning repair, fiberglass repair, rebar coating, steel roofing, and fuel and waste-water treatment tanks.
- Household and Shop
- Hand rails, support beams, lawn equipment, garage floors, pipe work, appliances, and lead-based paint encapsulation.
Can RustSeal Be Applied Over Existing Paint?
RustSeal bonds to sound, well-adhered painted surfaces once they have been scuff sanded and cleaned with KBS Klean. Loose or flaking paint has to come off first, because RustSeal bonds to whatever is directly beneath it and a failing layer will take the coating with it. On the underside of a vehicle, the safest approach is to treat any questionable area as bare metal and run all three kit steps.
RustSeal covers roughly 100 square feet per quart at 2 mils on porous rusted surfaces, so the two quarts in the Large Frame Coater Kit cover about 100 square feet with the two coats KBS recommends. That is enough for the entire underside of a typical car or light truck, including frame rails, floor pans, and suspension.
| Kit Component | Size Included | Typical Coverage |
|---|
| RustSeal | 2 Quarts | About 100 sq. ft. at 2 coats, or 200 sq. ft. at 1 coat |
| RustBlast | 1 Gallon | Sized to prep the same 100 sq. ft. area |
| KBS Klean | 1 Quart | Dilutes with water; sized to clean the same area |
Recoat window: RustSeal dries to recoat in about 2 hours at 75°F and 50 percent relative humidity, faster in higher humidity and slower in dry or cold conditions. Full cure is 24 hours. Minimum recommended dry film thickness is 3 to 5 mils, normally reached in 2 to 3 thin coats.
Do I Need the Large Kit or the Standard Frame Coater Kit?
Choose the Large Frame Coater Kit for a full vehicle underbody, a complete frame, a trailer, or any job in the 100 square foot range. The standard Frame Coater Kit is sized for smaller projects such as a single suspension assembly, a mower deck, or spot repairs. Coverage varies with surface profile, application method, and film thickness, so round up when the metal is heavily pitted.
Pro Tip: Apply RustSeal in thin coats and stir it, never shake it. Heavily pitted or porous rust soaks up the first coat, so plan on the first coat covering noticeably less area than the second. Reseal the can promptly and keep it out of open air, since a moisture-cured coating starts curing in the can once humidity gets to it.
The Large Frame Coater Kit differs from a rust-inhibitive primer and enamel system in that the kit includes the chemical prep and the finish coating is applied straight over treated rust. RustSeal cures to a completely non-porous, moisture-cured film rated to 500°F and needs no topcoat, while primer requires bare metal and an enamel topcoat to resist moisture.
| | Large Frame Coater Kit | Rust Primer + Enamel |
|---|
| Applied over rust | Yes, after RustBlast treats it; only loose scale must be removed | No, requires blasting or grinding to bare metal |
| Prep products included | Yes, KBS Klean and RustBlast are in the kit | No, degreaser and etch bought separately |
| Topcoat required | No, RustSeal is the finish | Yes, primer must be topcoated |
| Mixing required | No, single component, no hardener | Varies, many systems require a catalyst or reducer |
| Heat resistance | 500°F per Mil-D-3134F | Varies, commonly under 200°F |
| Coats needed | 2 coats of RustSeal | 1 primer plus 2 topcoat |
A primer and enamel system is the better choice when the panel is already blasted to bare metal and the finish has to match a specific automotive color code, since RustSeal is offered in a fixed range of 11 colors. When color match matters on top of rust protection, coat with RustSeal first and then apply the matched topcoat over it.
RustSeal is a finished coating and needs nothing over it to stop rust. A topcoat is worth adding only where the coated surface sees direct, prolonged sunlight, because extended UV exposure will dull and fade any color over time.
- Step 1 — KBS Klean
- Clean and degrease the metal so nothing interferes with the etch.
- Step 2 — RustBlast
- Remove surface rust and leave a zinc phosphate etch for the coating to grip.
- Step 3 — RustSeal
- Apply two thin coats to seal the metal permanently against moisture and oxygen.
- Optional Step 4 — UV Topcoat
- Add BlackTop or KBS Top Coater on sun-exposed surfaces to hold color and gloss.
See the Full 3-Step System
How to Stop Rust and Prevent Rust
Why rust keeps coming back after a repaint, and what the 3-step system does differently.
Read Article →
RustSeal: Insane Durability and Flexibility
A hands-on look at how far a cured RustSeal film bends and impacts before it fails.
Read Article →
Stacey David: Rust Prevention on Car Surfaces
Video walkthrough of the products used to stop and prevent rust on vehicle bodywork.
Watch →
Lawnmower Deck Rust Removal and Painting
Start-to-finish video on a heavily rusted deck using KBS Klean, RustBlast, and RustSeal.
Watch →
RustSeal How-To: Ford Flathead Restoration
A step-by-step project showing RustSeal applied to an engine and its related hardware.
Read Guide →
Customer Restoration Photos
Real frames, floor pans, and trailers coated by KBS customers with the 3-step system.
View Gallery →
Have questions before you buy? Find answers to the most common Large Frame Coater Kit questions below, or
order the Large Frame Coater Kit now and get it shipped same day.
The Large Frame Coater Kit is an all-inclusive 3-step rust prevention system that cleans, etches, and permanently seals up to 100 square feet of rusted or bare metal with two coats of RustSeal. What separates it from a primer and paint job is that the chemical prep is included and RustSeal goes directly over treated rust, so no blasting to bare metal is required. RustSeal is also the finish coat, not a base layer, so no topcoat is needed.
RustSeal covers roughly 100 square feet per quart at 2 mils on porous rusted surfaces. The two quarts in the Large Frame Coater Kit therefore cover about 100 square feet with the two coats KBS recommends, which is enough for the entire underside of a typical car or light truck. Heavily pitted metal absorbs more on the first coat, so coverage on the first pass will look lower than on the second.
The kit includes one quart of KBS Klean, one gallon of RustBlast, two quarts of RustSeal in any of the 11 available colors, durable nitrile gloves, two brushes, a stir stick, and complete printed instructions. Each of the two RustSeal quarts is selected separately at checkout, so two different colors can be ordered in one kit.
RustSeal dries to recoat in about 2 hours at 75°F and 50 percent relative humidity, and in as little as 1.5 to 2 hours at 85 to 100 percent humidity. In very dry air below 25 percent humidity, expect 8 hours or more. Full cure is 24 hours depending on humidity, since RustSeal cures by pulling moisture out of the air.
RustSeal cures across a working range from about 55°F to 90°F, and humidity matters more than temperature because RustSeal is moisture cured. Around 50 to 70 percent relative humidity gives predictable 2 to 3 hour recoat times. In very dry conditions, lightly misting the shop air will speed the cure. Store unopened cans between 41°F and 95°F, away from direct sunlight.
Clean the metal with KBS Klean diluted in water to remove oil, grease, and road film, then rinse. Apply RustBlast to dissolve surface rust and leave a zinc phosphate etch, then rinse and dry completely. Once the metal is dry, stir RustSeal thoroughly and brush, roll, or spray two thin coats, recoating inside the recoat window. Full directions are printed in the kit and posted on the RustSeal directions page.
RustSeal bonds to aluminum, fiberglass, and properly prepped concrete in addition to steel and cast iron, and it is regularly used for fiberglass repair, rebar coating, and sealing concrete floors. RustBlast is formulated for ferrous metal rust removal, so on aluminum and fiberglass the surface should be cleaned with KBS Klean and scuff sanded rather than acid etched. The one automotive area to avoid coating is the exhaust system.
Use KBS #1 Thinner and nothing else. Other solvents can cause premature coating failure or loss of adhesion if any residue is left behind on the tools or in the can. Clean up immediately, because cured RustSeal is extremely difficult to remove from a brush. An opened can that is resealed well and only opened for short periods holds up for roughly 1 to 2 months.
The Large Frame Coater Kit contains two quarts of RustSeal and a gallon of RustBlast, sized for roughly 100 square feet, which covers a full car or truck underbody, a complete frame, or a trailer. The standard Frame Coater Kit contains smaller quantities of the same three products and suits smaller jobs such as a single suspension assembly, a mower deck, or spot repairs.
No topcoat is required for rust protection, because RustSeal is a finished non-porous coating. A topcoat is worth adding only on surfaces exposed to prolonged direct sunlight, since extended UV will dull and fade any color over time. The Large All-In-One Chassis Kit adds BlackTop for a UV-stable satin black finish, and the Large All-In-One Kit adds KBS Top Coater for a color finish. RustSeal also accepts urethanes, epoxies, enamels, lacquers, and two-component automotive refinish products.
Sam Memmolo uses the KBS 3-Step Rust Prevention System to coat a rusty frame.
Repairing rust spots along the bottom of car doors with the same three products.
