We researched and compared the top fuel tank liners on the market, evaluating manufacturer specifications, industry standards (such as ASTM resistance tests), and aggregated owner feedback. Our goal is to help you choose a liner that seals leaks, prevents rust, and withstands modern ethanol-blended fuels. Below are our findings, including genuine limitations and who should skip each product.
| Photo | Product | Score | Buy |
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POR-15 Fuel Tank Repair Kit Best Overall 1 quart epoxy coating, covers up to 8 sq ft, includes cleaner and etching solution |
9.0 | 🛒 Check Price |
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KBS Coatings 3-Step Fuel Tank Sealer Kit Best for Classic Cars 1 quart sealer, covers up to 10 sq ft, includes cleaner and rust converter |
8.7 | 🛒 Check Price |
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Red-Kote Fuel Tank Liner Best Value 1 quart, covers up to 8 sq ft, single-step application |
8.4 | 🛒 Check Price |
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Caswell Inc. Epoxy Fuel Tank Sealer Best for Motorcycles 2-part epoxy, 8 oz kit covers up to 4 sq ft, designed for small tanks |
8.1 | 🛒 Check Price |
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Rust-Oleum High Performance Fuel Tank Sealer Easiest Application 1 quart, single-step, dries in 1 hour, covers up to 6 sq ft |
7.8 | 🛒 Check Price |
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Eastwood Fuel Tank Sealer Best for Rusty Tanks 1 quart, single-step, covers up to 8 sq ft, includes rust neutralizer |
7.3 | 🛒 Check Price |
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Bill Hirsch Fuel Tank Sealer Premium Choice 1 quart, two-part epoxy, covers up to 6 sq ft, requires thorough prep |
7.0 | 🛒 Check Price |
1. POR-15 Fuel Tank Repair Kit: Best Overall
The POR-15 Fuel Tank Repair Kit is a complete three-step system that includes a marine-grade cleaner, a metal-etching prep solution, and a high-build epoxy sealer. Based on the spec sheet and owner feedback, this liner forms a tough, non-porous barrier that adheres well to lightly rusted surfaces. We found that its resistance to ethanol and methanol blends is among the best in class, making it suitable for modern flex-fuel vehicles. However, the epoxy has a limited pot life after mixing, so you must work quickly and follow the instructions carefully.
This liner is ideal for DIYers restoring classic cars or treating rusty tanks. However, if you need a quick, one-step solution for a small leak, this kit may be overkill and the drying time (up to 48 hours) could be inconvenient. We recommend it for those who want a long-term repair and are willing to invest the effort.
- High-build epoxy resists ethanol and methanol blends up to E85
- Includes three-step system: cleaner, metal prep, and sealer
- Cures to a hard, non-porous finish that bonds to rusted surfaces
Pros: Excellent chemical resistance to modern fuels; Comprehensive kit with necessary pre-treatment chemicals
Cons: Requires precise mixing and application within pot life
2. KBS Coatings 3-Step Fuel Tank Sealer Kit: Best for Classic Cars
The KBS Coatings 3-Step Kit includes a rust converter that chemically neutralizes rust, saving you from hours of wire-brushing. The sealer itself is formulated to remain slightly flexible, which helps it endure temperature changes without cracking. Based on owner reports, it works well in vintage tanks with moderate rust. However, the manufacturer states it is not rated for E85, so it is best for vehicles using standard gasoline or diesel.
If you own a classic car with a steel tank that has surface rust and you want a forgiving application process, this kit is a strong choice. But if you plan to run high-ethanol fuel or need a liner for a motorcycle tank, we suggest looking at a more ethanol-resistant option. This product is not ideal for plastic tanks.
- Contains a rust converter that neutralizes existing rust
- Sealer is flexible to withstand thermal expansion
- Compatible with gasoline, diesel, and ethanol blends up to E15
Pros: Rust converter preps surface without extensive grinding; Flexible coating reduces risk of cracking
Cons: Not recommended for E85 or high-ethanol fuels
3. Red-Kote Fuel Tank Liner: Best Value
Red-Kote is a single-component liner that you can apply directly after cleaning the tank. It is one of the more budget-friendly options and works on both steel and plastic tanks. Owner feedback indicates it seals small leaks and prevents future rust, but it may not hold up as well in tanks with heavy pitting or extreme ethanol exposure. The coating remains somewhat softer than epoxy, which can be an advantage for flexibility but a disadvantage for abrasion resistance.
This liner is a good choice for a quick, low-cost repair on a daily driver with minor corrosion. However, if your tank has significant rust holes or you need maximum chemical resistance for E85, we recommend investing in a two-part epoxy system. Skip this if you want a permanent solution for a heavily rusted tank.
- Single-step coating, no mixing required
- Dries to a glossy, fuel-resistant film
- Works on steel and plastic tanks
Pros: Simple application process; Affordable compared to multi-step kits
Cons: Less durable than two-part epoxies for heavy rust
4. Caswell Inc. Epoxy Fuel Tank Sealer: Best for Motorcycles
Caswell’s epoxy sealer is a two-part system that cures into a hard, impermeable layer. Its low viscosity allows it to seep into crevices and around baffles, making it a favorite among motorcycle restorers. Based on user reports, it holds up well against ethanol and methanol. However, the kit size is small, and the price per square foot is higher than larger kits.
This is an excellent pick for motorcycle or small equipment tanks where precision and chemical resistance are critical. But if you are sealing a full-size car tank, you will need multiple kits, which becomes expensive. We recommend it only for small tanks or spot repairs.
- Two-part epoxy with high chemical resistance
- Low viscosity flows easily into tight spaces
- Cures to a hard, glossy finish
Pros: Excellent for small, complex tank interiors; Strong bond to metal and plastic
Cons: Smaller kit size may not be enough for large car tanks
5. Rust-Oleum High Performance Fuel Tank Sealer: Easiest Application
Rust-Oleum’s sealer is a single-component urethane that dries quickly, allowing you to finish the job in a day. It is easy to apply and requires less surface preparation than epoxy kits. However, based on our research, it is less resistant to ethanol and may soften over time with constant fuel exposure. Some owners report peeling after a year in high-ethanol use.
This product is best for a temporary fix or for vehicles that see occasional use and standard gasoline. If you need a permanent repair for a daily driver or a classic car, we suggest a more robust epoxy liner. Skip this if your tank has heavy rust or you use ethanol blends regularly.
- Fast-drying formula, recoat in 1 hour
- Spray or brush application
- Suitable for steel and aluminum tanks
Pros: Very fast cure time; Easy to apply with minimal prep
Cons: Not as durable as epoxy for long-term sealing
6. Eastwood Fuel Tank Sealer: Best for Rusty Tanks
Eastwood’s sealer includes a rust neutralizer that converts iron oxide into a stable compound, which can be beneficial for tanks with light surface rust. It is a single-step product, but owner feedback suggests that for heavy rust, it may not bond as well as a two-part epoxy. The manufacturer advises against using it with high-ethanol fuels, limiting its application.
This liner is suitable for classic cars running standard gasoline where rust is a concern but not severe. However, if you plan to use E15 or higher, or if your tank has pinholes, we recommend a more robust epoxy. It is not ideal for modern flex-fuel vehicles.
- Contains rust neutralizer to treat light rust
- Single-step application after cleaning
- Compatible with gasoline and diesel
Pros: Built-in rust treatment saves time; Good adhesion to rusty surfaces
Cons: Not recommended for ethanol blends above E10
7. Bill Hirsch Fuel Tank Sealer: Premium Choice
Bill Hirsch is a two-part epoxy that offers outstanding chemical resistance, but it comes at a premium price and requires meticulous surface preparation and temperature control during curing. Owner reviews note that if applied correctly, it provides a permanent seal. However, many DIYers find the process challenging, and mistakes can lead to peeling. The long cure time also means your vehicle is out of commission for days.
This sealer is best for professional restorers or enthusiasts with experience in tank coating who want the ultimate protection. For most average users, the high cost and demanding application make it a poor choice. We recommend skipping this unless you are confident in your ability to follow the exacting instructions and have a well-ventilated, temperature-controlled workspace.
- Two-part epoxy with high solids content
- Resistant to all fuels including ethanol and methanol
- Long curing time of 72 hours
Pros: Excellent chemical resistance; Very hard and durable finish
Cons: Very expensive per square foot; Complex application with strict temperature requirements
Frequently Asked Questions
What is the best fuel tank liner for ethanol fuels?
For high-ethanol blends like E85, we recommend two-part epoxy liners such as POR-15 or Caswell, as they have the highest chemical resistance. Single-component liners may soften or degrade over time with ethanol exposure.
Can I use a fuel tank liner on a plastic tank?
Yes, some liners like Red-Kote and Caswell are formulated for plastic tanks. However, always check the manufacturer’s compatibility list. Epoxy liners may not adhere well to certain plastics, so surface preparation is critical.
How long does a fuel tank liner last?
With proper application and fuel compatibility, a high-quality epoxy liner can last 10-20 years. Single-component liners may need reapplication after 5-10 years, especially with ethanol fuels.
Do I need to remove all rust before applying a liner?
Most liners require a clean, rust-free surface for best adhesion. Some products include rust converters that neutralize light rust, but heavy scaling should be removed mechanically. Skipping this step can lead to liner failure.
Can a fuel tank liner fix a leak?
Yes, liners can seal small pinhole leaks and hairline cracks. However, large holes or structural damage should be welded or patched before coating. A liner alone may not hold if the tank is severely compromised.
Our Verdict
After researching and comparing specifications, industry standards, and owner feedback, our top pick is the POR-15 Fuel Tank Repair Kit for its excellent chemical resistance, comprehensive system, and proven durability. For a more budget-friendly option, the Red-Kote Fuel Tank Liner offers good value for minor repairs. The runner-up is the KBS Coatings 3-Step Kit, ideal for classic cars with moderate rust. Choose based on your tank’s condition and fuel type.
