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How to repair a leaking lawnmower gas tank, step by step

Fuel dripping from your lawnmower gas tank is a hazardous issue that should be solved quickly. Fuel tank cracks are generally the result of long-time use or an accident. It can be the aftermath of the tank striking a low-hanging tree branch. Or debris falling on the lawnmower when it is parked or accidentally hit something.

Plastic built gas tanks are tough and irrepressible, but they can crack, split, break or spring a leak through accidents or misapplication. Polyethylene is a widely used material for lawnmower gas tanks. It is a material that is reasonably easy to repair at home.

How to repair a leaking lawnmower gas tank, step by step:

  • Step 1: Drain the tank
  • Step 2: Take out the gas tank
  • Step 3: Clean the gas tank and locate the problem
  • Step 4. Cut plastic pieces by knife or by Sand
  • Step 5. Take the dimensioning of the wrecked area
  • Step 6. Prepare for heating, i.e., heat the damaged area
  • Step 7. Place the patch material
  • Step 8.  Remove air bubbles
  • Step 9. Let the damaged area well-ventilated
  • Step 10. Attach the fuel lines to the fuel tank
  • Step 11. Refill the gas tank

This blog post will help you to fix your lawnmower’s leaking gas tank.

General systematic guide

Before starting the fixing process, you should gather the essential tools needed to repair the gas tank. These include a heating gun, knife, flat head screw, paper towel, hand gloves, and safety goggles. Additionally, a repair kit with epoxy resin and fiberglass, or for larger areas similar plastic as the tank.

Follow the steps mentioned below to fix the damaged or cracked plastic gas tank of your lawnmower.                                                                                     

Step 1. Drain the gas tank

Before you can start with the fix, you first have to drain the remaining gas from it. Use a suited gas container for it. Disconnect the fuel line attached to the carburetor, and let the remaining gas drain into the container. You can use this gas later again.

Step 2. Take out the gas tank

Use a screwdriver to unscrew the screws holding the tank to the lawnmower and remove it. Check again if it is empty, as it can still contain some leftover gas. Use the torch to check for debris and try to remove it.

Step 3. Clean the gas tank and locate the problem

Clean all the dirt from the gas tank by using an old rag. Then clean the gas tank using liquid soap and warm water. And finally, remove all the unwanted pieces of dirt that are still on it by rubbing the tank with alcohol. It is unnecessary to be spotless, but the cleaner it is, the easier it is to fix it. Now use a strong torchlight and shine inside the tank. This makes it much easier to spot cracks or small holes. Mark the locations with a marker.

Step 4. Cut plastic pieces by knife or by Sand

If the crack is bigger, there are two techniques to remove the loose plastic from a damaged area:

  1. Knife: Use the box knife to take out all kinds of loose strings of plastic from the wrecked area.
  2. Sanding: Sand the area that needs to be fixed with sandpaper. The location must be “roughed up” to permit a solid bond for the adhesive. The ridges from roughing up the plastic will enable the adhesive to be settled down and grab hold, making for a much resilient bond. Using a rag, you have to rub the area of all dust after sanding

If the leak is small it only needs to be sanded.

Step 5. Take the dimensioning of the wrecked area. 

Depending on how you will fix the leak, with some additional plastic or with the repair kit the following needs to be done:

  1. Repair kit: Using scissors, cut the encircled fiberglass repair patch to fit the area. Cut the patch to slightly overlapping the place that is to be fixed.
  2. Plastic method: Cut the plastic to the needed dimensions to completely cover the damaged area. Make the size 1.5 times larger, so there is a significant overlap outside of the damaged area.

Step 6. Prepare for heating and Heat the damaged area.

When the plastic patch material will be used and is cut to the correct dimension, it is time to heat things. First, start heating the damaged area with the aid of the heat gun. During this process, you need to care about two things. Firstly, heat the damaged area from some distance so that the plastic never burns or give smoke. Secondly, the goal is to make the plastic flexible without melting it or losing its shape.

Step 7. Place the patch material.

When you see the place is slowly becoming flexible and feeling a little wet, place the pre-prepared patch material on it. Coat the area to be repaired using the applicator stick after the patch is pertained, enveloping the patch with more adhesive while imbricating the edges. Enact the plastic epoxy adhesive to the tank over and around the spores. Extend the adhesive well and away farther out than the volume of the piece you have cut. Wrap the complete patch with more epoxy plastic adhesive, and do not go lightly. Confirm that the entire material patch is covered, and ensure that the bond is well applied past the patch’s ends. Continue heating until the patch element becomes wet as well. Remove the heat gun and place it in a safe place. When this is done correctly, there should be no sign of the patch viewing through.

Step 8. Remove air bubbles:

Take the spatula and then use some light pressure to the heated patch area to remove any air bubble from that area. Please do not use too much pressure, as it will ruin the shape of the tank. After all the air bubbles are removed, wait until the patch element has adhered well to the tank. 

When the patch is cool, check the tank. If you sense that the patch is thin, apply an additional patch again following the previous process. Put pressure on the material piece onto the adhesive that covers the hole. Please make sure it is pressed firmly into the adhesive and that all sides and corners are pressed into epoxy.

Step 9. Let the damaged area be well ventilated.

Permit the epoxy to dry. Check the manufacturer’s guidelines on how much time this should take. Some epoxy formulas cure within five minutes. Others will take half an hour or more.

Step 10. Attach the fuel lines to the fuel tank

Carefully reattach the fuel lines and adjust the component to the main assembly. Push the fuel line onto the tank fitting and secure it with the spring clamp. Make sure they are connected correctly, so no fuel leakage occurs.

Step 11. Refill the Gas Tank

Clean the repaired area with a paper towel. Fill the gas tank with gas and check the tank again for leaks. If all is ok and there are no leaks, the fix is done!

Additional Concerns:

Check the following concerns that are important to repair a leaking gas tank: 

  • Clean: Clean all materials and the gas tank before starting the fixing process.
  • Heat slowely: Heat the gas tank slowly; otherwise, it will burn or be damaged.
  • Suitable patch: Use suitable plastic built when repairing a plastic gas tank.
  • Test the plastic patch: Test the plastic piece before fixing it with the tank because every plastic has a different melting temperature. 
  • Hot plastic: Do not touch hot plastic with bare hands.
  • Empty the gas tank: Empty the gas tank before fixing it. Otherwise, it may explode when you heat the tank. 
  • If still leaking: If any leakage appears after fixing, vacate the gas tank completely and cleans it to fix it again. 
  • Epoxy: Many adhesives like epoxy plastic resin melt the plastic through a chemical reaction. It will make the patch as strong as the original plastic tank, and these patches will last the lifetime of your mower.

Frequently asked questions

1. How can I fix a hole in my gas tank?

At first, find the leakage or point of escape in the gas tank. Then, sand the Leaky Area of the tank and wipe the surface. Now, mix the epoxy and apply the epoxy. In the end, insert the epoxy in the hole and fill the tank with gas.

2. How to Repair a Black Plastic Lawn Mower Gas Tank?

Start with draining the tank of any residual gas. Then, Sand the area that needs to be fixed with the sandpaper that comes with the kit. Besides, by using the scissors, cut the enclosed fiberglass repair patch to fit the area. Now, Mix the two-part adhesive compound from the tubes in the repair kit.

3. How do you seal a plastic gas tank leak?

Firstly, Seal the Plastic Gas Tank with the help of Epoxy Glue. Next, Drain the gasoline from the tank and let it dry. Last but not least, Sand the area around the spores or cracks, and dirt-free the room with a shop cloth saturated with rubbing alcohol. Finally, blend the epoxy and put it all around the perimeter of the opening.

Final remarks

You always have to remember a golden rule that a machine takes care of you as long as it’s being taken care of. This article explains in detail how to fix a leaking plastic gas tank on a lawnmower. It is not a complicated task, but it takes some time. Another solution would be to replace the fuel tank, but that will be more costly.

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  1. Valerie Larson says:

    Great step-by-step guide, will try this on my lawnmower

    • Allard Vdhooft says:

      Thank you, Valerie! I’m glad you found the guide helpful. Good luck fixing your lawnmower’s gas tank – you got this!

  2. Lloyd Mcdonalid says:

    Can I use a different type of adhesive instead of epoxy resin?

    • Allard Vdhooft says:

      Using a different adhesive instead of epoxy resin may not provide a strong and long-lasting fix for your lawnmower gas tank. It’s best to follow the recommended repair steps for a durable solution.

  3. Jennie Snyder says:

    Thank you for providing such a comprehensive guide on repairing a lawnmower gas tank.

    • Allard Vdhooft says:

      Thank you for your kind words, Jennie! I’m glad you found the guide helpful in repairing your lawnmower gas tank. Happy mowing!

  4. Mathew Garcia says:

    The step by step instructions are clear and easy to follow.

    • Allard Vdhooft says:

      Thank you for your positive feedback, Mathew. I’m glad the instructions were helpful to you!

  5. Dianne Murray says:

    Can the tank be painted or coated after the repair to protect it further?

    • Allard Vdhooft says:

      Yes, you can paint or coat the repaired area of your gas tank for further protection. Just make sure to use a suitable coating that is compatible with the material of your tank.

  6. Wade Smith says:

    I never thought I could do this myself, thanks for the guide!

    • Allard Vdhooft says:

      Thank you, Wade! I’m glad the guide helped you fix your lawnmower’s gas tank. Your safety is important, so always take precautions when dealing with gasoline.

  7. Brad Carroll says:

    What is the average cost of the repair materials needed for this fix?

    • Allard Vdhooft says:

      The average cost of repair materials for fixing a leaking lawnmower gas tank can range from $15 to $30, depending on the size of the repair area.

  8. Jerry Mcdonalid says:

    This is so helpful, I fixed my lawnmower tank thanks to this guide!

    • Allard Vdhooft says:

      Thank you, Jerry! I’m glad that the guide was helpful in fixing your lawnmower’s gas tank. Happy mowing!

  9. Lena Fuller says:

    I never knew sanding was a part of fixing a gas tank, very interesting

  10. Sophia Kim says:

    Does the type of plastic used for the patch affect the durability of the fix?

    • Allard Vdhooft says:

      Hi Sophia, the type of plastic used for the patch can affect the durability of the fix. Polyethylene is commonly used for lawnmower gas tanks due to its repair-friendly nature. Hope this helps!

  11. Sarah Rhodes says:

    Good to know that repairing a gas tank is possible, thanks!

    • Allard Vdhooft says:

      I’m glad you found the information helpful, Sarah! Repairing a gas tank can save you time and money. Good luck with fixing your lawnmower!

  12. Sherri Herrera says:

    I will definitely try to fix my lawnmower tank following these steps.

    • Allard Vdhooft says:

      Thank you, Sherri! I’m glad the steps provided will help you fix your lawnmower gas tank. Remember to work carefully and take your time to ensure a proper repair. Good luck!

  13. Alexa Mills says:

    Are there any specific safety precautions to keep in mind during the repair process?

    • Allard Vdhooft says:

      Thank you for your question, Alexa. When repairing a gas tank, remember to work in a well-ventilated area, wear safety goggles and gloves, and avoid any open flames or sparks to prevent accidents.

  14. Roger Ellis says:

    Is it safe to do this repair indoors?

    • Allard Vdhooft says:

      It is safer to repair your lawnmower gas tank outdoors due to the heating process involved. Follow the steps carefully, wear protective gear, and ensure proper ventilation. Stay safe!

  15. Glenda Martinez says:

    How long does the repaired tank last before needing another fix?

    • Allard Vdhooft says:

      Hi Glenda, the repaired tank should last indefinitely if done correctly. Following the steps in the blog post will ensure a strong and long-lasting fix. Hope this helps!

  16. Erik Holt says:

    Very informative, I didn’t know plastic tanks could be repaired at home

    • Allard Vdhooft says:

      Thank you, Erik! I’m glad you found the information helpful. Repairing a plastic tank at home can save time and money. Let me know if you have any more questions.

  17. April Peck says:

    How long does the repaired tank last after following these steps?

    • Allard Vdhooft says:

      Repairing a lawnmower gas tank can last for the lifetime of the mower if done correctly. Regular maintenance and care can ensure the tank remains intact for a long time.

  18. Marvin Sanchez says:

    Thank you for sharing this valuable information, very useful.

    • Allard Vdhooft says:

      Thank you for the positive feedback, Marvin! I’m glad you found the information valuable. Let me know if you have any other questions or need further assistance.

  19. Lisa Warren says:

    I am so glad I stumbled upon this article, it’s exactly what I needed.

    • Allard Vdhooft says:

      Thank you, Lisa! I’m glad you found the article helpful. With proper tools and steps, fixing a leaking gas tank is manageable. Let me know if you have any questions.

  20. Riley Jennings says:

    What if I don’t have a heating gun, are there any alternatives?

    • Allard Vdhooft says:

      Hi Riley, if you don’t have a heating gun, you can use a heat gun or a blow dryer as an alternative to fix your lawnmower’s leaking gas tank. Good luck with your repair!

  21. Carmen Schmidt says:

    Can you recommend a specific brand or type of repair kit for this task?

    • Allard Vdhooft says:

      I recommend using an epoxy repair kit for fixing your lawnmower’s gas tank. It’s a cost-effective and durable solution for plugging leaks in plastic tanks.

  22. Tim Ross says:

    I had no idea you could repair a gas tank at home, amazing!

    • Allard Vdhooft says:

      Thank you, Tim! I’m glad you found the information helpful. Repairing a gas tank at home can save time and money. Let me know if you have any more questions.

  23. Vernon Willis says:

    Are there any signs to look for that indicate the tank may need repair?

    • Allard Vdhooft says:

      There are signs to look for, such as fuel dripping from the tank or cracks from accidents or debris. Check out the repair steps in the blog post to help fix any issues.

  24. Harper Snyder says:

    Is it necessary to have prior experience in repairs to do this on my own?

    • Allard Vdhooft says:

      You don’t need prior repair experience to fix your gas tank. Just follow the steps outlined in the blog post to repair it at home. Good luck!

  25. Brandie Harrison says:

    I appreciate the detailed instructions provided in this post.

    • Allard Vdhooft says:

      Thank you for your kind words, Brandie! I’m glad you found the instructions helpful. Let me know if you have any other questions or need further assistance.

  26. Albert Banks says:

    Is there a risk of the tank leaking again after the repair is done?

    • Allard Vdhooft says:

      Repairing a leaking gas tank can be a safe and effective solution if done properly. Be cautious of using the correct materials and techniques to prevent future leaks.

  27. Susan Rice says:

    Great tips on fixing the tank without spending too much money.

    • Allard Vdhooft says:

      Thank you, Susan! I’m glad you found the tips helpful. Let me know if you have any questions. Happy fixing!

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