What is the Auto Fuel Tank Sealer Kit?
The KBS Auto Fuel Tank Sealer Kit is an all-inclusive 3-step system that cleans, preps, and permanently seals automotive gas tanks up to 25 gallons. The kit pairs KBS Klean and RustBlast with Gold Standard Tank Sealer, a fuel-impervious coating that stops rust and corrosion and permanently seals pinholes and weld seams on steel, aluminum, and fiberglass tanks.
3-Step
Klean → RustBlast → Seal
Gold Standard Tank Sealer is a single-component, ready-to-use moisture-cured urethane that forms a silver metallic, lightly pigmented coating inside the tank that resembles the original look. The cured film stays flexible, so it expands and contracts with the tank instead of cracking loose, and it is impervious to all modern day fuels, alcohol additives, and most solvents.
The Auto Fuel Tank Sealer Kit is all-inclusive: it contains a half gallon of KBS Klean (a water-based, heavy-duty cleaner and degreaser) and a quart of RustBlast (a powerful rust remover and metal etch) alongside the quart of Tank Sealer. Those two prep products are formulated to promote adhesion of the Tank Sealer by leaving an ideal anchor pattern and a zinc phosphate film.
Gold Standard Tank Sealer permanently seals pinholes and weld seams on steel, aluminum, and fiberglass tanks. Satisfaction guaranteed!
One pour-coat-and-drain application, drained until it stops dripping, then 96 hours to full cure before fuel goes back in.
The Auto Fuel Tank Sealer Kit contains everything needed to clean, prep, and seal a fuel tank up to 25 gallons in a single purchase: a half gallon of KBS Klean, a quart of RustBlast, a quart of Gold Standard Tank Sealer, black nitrile gloves, a stir stick, and detailed written instructions. No separate degreaser, metal etch, or sealer purchase is required.
- KBS Klean, 2 Quarts (1/2 Gallon) — Water-based, heavy-duty cleaner and degreaser. Mixed 1:1 with hot water, it removes the oils, gum, varnish, and residues every tank carries, old or new.
- RustBlast, Quart — Powerful rust remover and acid metal etch. It neutralizes existing rust and leaves a zinc phosphate film and anchor pattern that the Tank Sealer bonds to.
- Gold Standard Tank Sealer, Quart — Single-component, fuel-impervious coating that permanently seals pinholes, weld seams, and remaining rust on steel, aluminum, and fiberglass tanks.
- Black Nitrile Gloves — Chemical-resistant gloves. Cured Tank Sealer cannot be removed from skin by any solvent, so gloves are worn for all three steps.
- Stir Stick — For lifting and dispersing the settled silver pigment before pouring. Tank Sealer is stirred, never shaken.
- Detailed Step-by-Step Instructions — Written directions covering the temperature window, dwell times, drying, draining, and cure time for all three steps.
The Auto Fuel Tank Sealer Kit eliminates rust and corrosion permanently rather than covering it, and Gold Standard Tank Sealer bonds to and seals over any rust that remains after prep. The cured coating is impervious to all modern day fuels, alcohol additives, and most solvents, holds a maximum operating temperature of 600°F, and stays flexible enough to move with the tank through heat cycles and vibration.
- Silver Metallic Permanent Coating: A lightly pigmented film that resembles the original look of a clean tank interior.
- Eliminates Rust and Corrosion: Stops active rust rather than sealing it in behind a decorative layer.
- Permanently Seals Pinholes and Weld Seams: Bridges pinholes and leaky seams as the coating cures.
- Impervious to Modern Fuels: Resists all modern day fuels, alcohol additives, and most solvents, including ethanol-blended pump gas.
- Flexible Coating: Expands and contracts with the tank instead of cracking under thermal stress and road vibration.
- Single Thin Coat: One properly drained coat is the complete sealing step, with no recoat window to manage.
- 600°F Maximum Operating Temperature: The cured coating holds up to 600°F (316°C), well beyond anything a fuel tank sees in service.
- Non-Flammable: Safer to handle and store than solvent-heavy tank liner alternatives.
- Environmentally Safe: Formulated without Methyl Ethyl Ketone (MEK).
- Complete 3-Step System: KBS Klean, RustBlast, and Gold Standard Tank Sealer are formulated to work together, which is what makes the bond permanent.
The Auto Fuel Tank Sealer Kit works on steel, aluminum, and fiberglass tanks up to 25 gallons, which covers most car, truck, and street rod fuel tanks. Gold Standard Tank Sealer also seals diesel tanks, oil tanks, utility tanks, non-potable water tanks, and air compressor tanks, so the tank material and the liquid it holds do not limit which tanks can be sealed.
- Automotive
- Car, truck, street rod, and classic vehicle gas tanks up to 25 gallons, including tanks pulled from long-stored project vehicles.
- Fuel Types
- Gasoline and diesel tanks, including tanks running ethanol-blended pump fuel, plus heating and lubricating oil tanks.
- Shop, Farm and Utility
- Utility tanks, air compressor tanks, and non-potable water tanks. Gold Standard Tank Sealer is not for potable water.
- Materials
- Steel, aluminum, and fiberglass. Fiberglass tanks follow a shortened 2-minute RustBlast step instead of the standard 30 to 60 minutes.
Can the Auto Fuel Tank Sealer Kit Be Used on a Fiberglass Tank?
Yes. The procedure is the same except for Step 2: RustBlast wets a fiberglass surface for only 2 minutes rather than 30 to 60 minutes, because the goal there is an acidic etch and a zinc phosphate film, not rust removal. Fiberglass holds moisture, so the tank must be dried completely with forced air from a shop vac, blow dryer, or fan before the Tank Sealer goes in.
Does the Tank Have to Come Out of the Vehicle?
Yes. Proper fuel tank sealing requires the tank to be removed from the vehicle, drained, and stripped of fittings such as floats, sending units, and filters. All openings are then sealed with high quality duct tape, rubber patches taped over, or cork-like stoppers, because every step of the 3-Step System depends on rotating the tank to keep all interior surfaces wet.
One Auto Fuel Tank Sealer Kit seals a single automotive tank up to 25 gallons, using the full quart of Gold Standard Tank Sealer as one thin, well-drained coat. Tank Sealer covers roughly 100 square feet per quart at 2 mils, so tank surface area rather than fuel capacity is what actually determines the size needed.
Timing that matters: Seal the tank within 10 days of finishing the KBS Klean and RustBlast prep steps, and allow 96 hours for maximum cure before refilling with fuel. Touch dry is 4 to 6 hours at 77°F, but touch dry is not cured.
Pro Tip: After draining, rotate the tank side to side every 5 minutes until it stops dripping. Puddled sealer traps gas underneath, which shows up as foaming or bubbling and can keep the coating from curing and adhering.
The Auto Fuel Tank Sealer Kit differs from replacing a rusted fuel tank in that sealing keeps the original tank: Gold Standard Tank Sealer bonds to the existing rust and seals pinholes and weld seams from the inside, while replacement means sourcing a new tank that matches the vehicle's sender, straps, and filler neck. On an older or uncommon vehicle, that matching tank often does not exist.
| | Auto Fuel Tank Sealer Kit | Replacing the Tank |
|---|
| Keeps the original tank | Yes, including date-coded and hard-to-source tanks | No |
| Handles existing rust | Yes, seals over remaining rust after prep | Not applicable, rust is discarded with the tank |
| Seals pinholes and weld seams | Yes, permanently, as the coating cures | Not applicable |
| Typical cost | One kit at $77.00 for tanks up to 25 gallons | Varies widely by vehicle, commonly several hundred dollars |
| Time to complete | Prep plus a 96 hour cure before fuel | As long as sourcing the correct tank takes |
| Protects against future rust | Yes, fuel no longer touches the tank walls | No, a bare new tank can rust the same way |
The KBS Tank Sealer System restores a sound tank to service, sealing pinholes, weld seams and a rusted interior that would otherwise send the tank to the scrap pile. What the system does not do is rebuild a tank that has already failed structurally: split seams, holes larger than a patch can carry, or rot that leaves too little sound metal for a coating to bond to. Confirm the tank is sound and the sealer handles the rest.
Let the tank air-dry naturally in a well-ventilated area, out of direct sun and away from direct heat, for the full 96 hours. Heating the tank does not speed the cure and can hinder adhesion. Test the tank with water before refilling with fuel. Use any left-over Sealer immediately for exterior patching before it hardens in the can.
- Step 1 — KBS Klean
- Mixed 1:1 with hot water, soaked and rotated until the tank rinses clear.
- Step 2 — RustBlast
- Full strength, rolled and tipped every 5 minutes for 30 to 60 minutes, then rinsed and dried completely with forced air.
- Step 3 — Gold Standard Tank Sealer
- Stirred, poured, rotated for up to 30 minutes, then drained until it stops dripping.
See the Full 3-Step Tank Sealing System
A rusted tank interior before prep, and the same tank after one coat of Gold Standard Tank Sealer.
Patience When Using Tank Sealer
Why slowing down between steps is the single biggest factor in getting a permanent seal.
Read Article →
Restore the Inside of Your Tank to Like New
How the KBS Fuel Tank Sealer System removes rust and restores a tank interior.
Read Article →
Simple Steps to Seal a Gas Tank
A step-by-step video walkthrough of sealing a gas tank with the KBS Tank Sealer System.
Watch Video →
Tank Sealer Application Directions (TDS)
Full directions and technical data for the KBS 3-Step Tank Sealer System.
Read Directions →
How Much Tank Sealer Do I Need?
Match your tank's size and shape to the right KBS kit before you order.
Read Guide →
KBS Coatings Customer Photos
Real before-and-after tank sealing results submitted by KBS customers.
See Gallery →
A walkthrough of what comes in the KBS all-inclusive Gas Tank Sealer Kit and how the three steps fit together.
Have questions before you buy? Find answers to the most common fuel tank sealing questions below, or
order the Auto Fuel Tank Sealer Kit now and get it shipped same day.
The best fuel tank sealant is one that bonds to a properly prepped interior and stays flexible after it cures. KBS Gold Standard Tank Sealer is a single-component, moisture-cured urethane that seals steel, aluminum, and fiberglass tanks in one thin coat, bonds over remaining rust, and is impervious to all modern day fuels, alcohol additives, and most solvents. What separates it from a sealer used alone is the prep: the Auto Fuel Tank Sealer Kit includes the KBS Klean degreaser and RustBlast metal etch that make the bond permanent.
A fuel tank sealer is worth it when the tank is structurally sound but rusted, pinholed, or leaking at a weld seam. One Auto Fuel Tank Sealer Kit at $77.00 seals a tank up to 25 gallons and keeps the original tank in the vehicle, which matters most on older and uncommon vehicles where a correct replacement tank is expensive or simply not available. It is not worth it on a tank with split seams or rot severe enough that too little sound metal remains for a coating to bond to.
For a leaking fuel tank, use an interior tank sealer rather than an exterior patch or tape. Gold Standard Tank Sealer permanently seals pinholes and weld seams from the inside as it cures, so fuel stops reaching the leak path at all. For holes larger than the tip of a pin, repair the outside first: KBS BackBone Reinforcing Mesh embeds into wet Sealer for pinhole and seam reinforcement, and KBS NuMetal Epoxy Putty patches larger holes and cures for 12 hours before the interior is sealed.
Gold Standard Tank Sealer is a permanent coating when it is applied over a properly cleaned and etched surface. Because the cured film is impervious to all modern day fuels and alcohol additives and stays flexible enough to move with the tank, it does not soften, peel, or crack loose the way older paint-type and adhesive-type liners do. Nearly every sealer failure traces back to prep that was rushed, a tank that was not completely dry, or excess sealer left pooling inside the tank.
The best gas tank repair kit is a complete one, because a sealer bonds only as well as the prep underneath it. The KBS Auto Fuel Tank Sealer Kit includes all three stages in one purchase: a half gallon of KBS Klean to degrease, a quart of RustBlast to remove rust and etch the metal, and a quart of Gold Standard Tank Sealer to seal the interior permanently, plus gloves, a stir stick, and written instructions. Sealer-only purchases leave the buyer sourcing a separate degreaser and metal etch before work can start.
General-purpose rubberized spray and tape products are exterior sealers and are not formulated for constant immersion in gasoline, diesel, or ethanol-blended fuel, so they are a short-term stopgap on a fuel tank at best. A gas tank leak is sealed from the inside, where the fuel actually is. Gold Standard Tank Sealer cures into a fuel-impervious film across the entire interior surface, which seals the pinhole or weld seam and protects the rest of the tank at the same time.
Drain the tank, remove it from the vehicle, pull the fittings, and seal every opening. Mix KBS Klean 1:1 with hot water, pour it in, and soak while rotating the tank at intervals until it rinses clear. Pour in full-strength RustBlast and roll and tip the tank every 5 minutes for 30 to 60 minutes, then rinse and dry completely with forced air. Stir the Tank Sealer without shaking it, pour the full quart in, rotate for up to 30 minutes, then drain all excess and rotate every 5 minutes until it stops dripping.
Apply Gold Standard Tank Sealer between 55°F and 82°F (13°C to 28°C) in moderate to dry conditions. It is a moisture-cured urethane, so sealing in rainy or humid conditions cures the surface too quickly and causes bubbling from gas entrapment beneath the top layer. Let the tank cool to room temperature before sealing, and never seal a tank sitting in direct sunlight.
Use KBS #1 Thinner for immediate cleanup of Gold Standard Tank Sealer, and clear Sealer off threads and fuel lines before it cures, because cured Sealer cannot be removed by any solvent. KBS Klean and RustBlast rinse away with water. Wear the included nitrile gloves throughout: if Sealer stains skin, only time removes it. Let drained Sealer harden in the can with the lid off, since a sealed can can build pressure and pop the lid.
Let the tank air-dry naturally in a well-ventilated area for 96 hours, out of direct sun and away from direct heat, since heating the tank does not speed the cure and can hinder adhesion. Touch dry is 4 to 6 hours at 77°F, but that is not cured. Test the tank with water before refilling with fuel. If the outside of the tank also needs protection, KBS RustSeal and BlackTop finish the exterior.
