Often yes, but it depends on the product, its cure and the fuel, so check the maker’s data sheet for your own fuel and conditions before you trust any epoxy near gasoline.
What do chemical resistance tables say about epoxy and gasoline?
Engineering Toolbox publishes an epoxy chemical resistance table. That table rates epoxy resistance to gasoline as “Excellent.” It also rates kerosene as “Excellent.”
That sounds simple, but a table rating is only a starting point for your job. The same table carries its own warning. It says, “Always check the chemical resistance with the epoxy manufacturer.”
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What about ethanol, diesel and other fluids?
The same table rates ethyl alcohol “Excellent” for temperatures under 120 °F (50 °C). It rates diesel fuel “Excellent” for temperatures under 71 °F (22 °C). Note that the diesel rating comes with a much lower temperature limit.
Not every fluid is fine. The table lists acetone as “Not Recommended.”
Master Bond, a maker of industrial epoxies, describes one of its two-part epoxy systems as having “outstanding resistance” to gasoline, gasohol and fuels. It says the system can resist prolonged immersion in solvents, fuels, oils, alcohols, acids and water. Master Bond’s page gives no test data, concentrations or exposure temperatures for those claims. So check the data for your own use.
Does the cure matter?
The cure schedule is part of the product data. Master Bond lists cure schedules of 24 to 48 hours at 75 °F or 1 to 2 hours at 200 °F for that system. It also says that to optimize chemical resistance it recommends adding heat.
So follow the maker’s cure schedule. If the maker says heat-cure, heat-cure.
Can you use epoxy to seal a gas tank?
This is advice. A fuel tank repair is a safety job. Use a product the maker states is for fuel tanks. Read its data sheet. Let it cure fully, and heat-cure if the maker says so. Test a small piece first. For background, see our guide on how to seal with epoxy and the difference between epoxy and sealant.
How to check your product before you trust it
Do not assume every epoxy behaves like the table. Check your own product.
- Find the maker’s chemical resistance data for gasoline and your fuel.
- Confirm the cure schedule and any heat-cure step.
- Test a small cured sample in the fuel first.
- Use a product the maker states is for fuel tanks.
Always check the chemical resistance with the epoxy manufacturer.
That line comes from Engineering Toolbox.
How to read a rating like Excellent
A rating in a table covers the conditions the table was written for. Advice: treat “Excellent” as a starting point only. Engineering Toolbox lists no temperature limit next to gasoline or kerosene. It does attach a limit to ethyl alcohol and to diesel fuel, so the same word can come with a condition.
Master Bond’s page gives no test data, concentrations or exposure temperatures for its claims. That means you cannot compare its numbers with your own setup from the page alone.
What to ask the maker
Advice: write to the maker or read the data sheet before the job. Ask for resistance data for your exact fuel, including any ethanol blend. Ask what temperature that data covers and which cure schedule it assumes. If heat is part of your job, ask for data at your temperature. Keep the answer with your project notes.
FAQ
Does epoxy dissolve in gasoline?
Engineering Toolbox rates epoxy resistance to gasoline as “Excellent.” Check your product’s data sheet for your conditions.
Is epoxy resistant to ethanol?
Engineering Toolbox rates epoxy resistance to ethyl alcohol as “Excellent” under 120 °F (50 °C). Check your product’s data sheet for your conditions.
Which fluids should epoxy stay away from?
The table lists acetone as “Not Recommended.” For any other fluid, check the maker’s data before you rely on it.
Martin Flood
Martin Flood has been working in the construction industry for over 20 years as a general contractor with expertise in remodeling projects that are large or small. He has furthered his career by specializing in epoxy resin flooring, providing excellent service to both commercial and residential clients. Martin’s experience enables him to offer professional advice on how to choose the right type of project based on your needs and budget.
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