Plastic gas tanks that are specifically made for lawnmowers are conceived and built to be both sturdy and durable. They are, usually extremely reliable.
However, it is inevitable, that after a certain amount of time and use, they are subject to breaking, splitting, and above all cracking.
It’s a good idea to know how you can repair your lawnmower’s plastic gas tank as opposed to having to go out and automatically purchase a replacement.
Most plastic gas tanks are manufactured in polyethylene, meaning that in many cases they can be repaired and relatively easily, and your repair may even last the life of your lawnmower.
While it may seem like a complicated task, it’s really quite doable if you are prepared.
Considerations Before Beginning
- Plan on having an hour at your disposal for your repair. You may only need a fraction of an hour, but it’s a good idea to not be in a hurry.
- You should repair your lawnmower gas tank with the idea that this will be a permanent repair that needs to last over time.
- You will need to use epoxy. When you apply the epoxy, you will need to be pretty quick in the application, so the plastic does not dry out while you are still repairing the gas tank. The epoxy may actually melt into the gas tank’s plastic, but that is to be expected.
Necessary Tools and Materials
- PPE Work gloves
- PPE respirator and goggles especially if you are working indoors
- Epoxy/Plastic adhesive
- A patch in plastic or fiberglass
- A metal spatula
- Some sandpaper
- A Phillips screwdriver
- A utility knife
- A brush
Your only real expense will be for the epoxy and the patch if you don’t have any on hand.
Step-By-Step Guide – How to Fix Plastic Gas Tank on Lawn Mower
Step 1. It is fundamental that you do your repair away from the mower. In this way, you will have more space for movement, and you will avoid that any spills damage your mower.
Wear your PPE gloves. Move your mower to a flat surface. If your tank has a hole or a large crack, you need to avoid spilling the fuel that may be running out of the damaged gas tank.
Step 2. Drain any remaining fuel from your gas tank before beginning. This can be done by propping your lawnmower on a set of sawhorses to allow access to the underside. DO NOT TIP the lawnmower on its side. Unplug the wire to the lawn mower sparkplug.
Place a container underneath the gas tank. Remove the fuel line from the mower’s carburetor and run the remaining gasoline into the container sitting beneath. If your lawnmower does not feature a fuel line, use a siphon for gasoline.
Step 3. Begin by removing the gas tank from the lawnmower. Locate the screws that keep the tank connected to the mower. Remove them all. Remove any clamps for the gas hose that are attached to the motor and any screws. Now remove the gas tank.
Step 4. Prepare the gas tank for repair. A good cleaning is necessary for your personal safety. If you have already successfully drained the gas tank, simply check it for any remaining fuel and remove all residual gas.
For the application of epoxy, the tank should be very clean. Remove debris, dirt, mower grease, grime, wax, or any contaminant present in the tank.
Here, a brush, utility knife, or rag can help you remove stubborn substances. Clean inside and outside. Allow the plastic fuel tank to dry or dry with clean rags.
Step 5. Now cut any plastic or rough material with the utility knife where the crack or hole is located on the tank. For easier cutting, try heating your knife edge with a heat gun.
Proceed to remove any excess pieces that will compromise your repair. Sand the entire area thoroughly. The surface needs to be rough to the touch so that the epoxy attaches more easily and quickly to the damaged spot.
Step 6. Prepare the size of your patch. Measure the area and cut a patch that is the correct size. Compare the patch to the hole or crack.
When you cut the patch, cut it one and one-half times larger than the damage. If the patch is too big, it will require cutting to size. The entire damaged area needs to be covered by the patch.
Step 7. Prepare your adhesive for the patching. When working with epoxy, follow carefully the instructions to prevent error.
Generally, epoxy comes with two ingredients that you need to mix. By combining these two ingredients, you will produce the adhesive. The epoxy should come with its own stick for mixing. Now that your adhesive is ready, you will need to move quickly for the application.
Step 8. Apply the adhesive to the area that you have prepared for repair. Using a metal spatula to prevent melting. Paint the damaged area and the surrounding border. Do leave some epoxy for the patch’s exterior.
Step 9. Place the patch over the damaged spot with your hands wearing gloves. Press the patch down onto the adhesive tightly.
Step 10. Paint the entire patch and surrounding area with the remaining epoxy adhesive. It is necessary to cover the patch’s edges thoroughly.
Step 11. Allow the repair to dry completely and to cool completely. The tank should rest for at least three hours after repair. During this time inspect the area for apparent weaknesses or thinness. If you suspect a weak spot, apply some more epoxy to the spot.
Step 12. Once the epoxy is totally cool, do a final inspection for weak points. If there are no apparent weaknesses, you will have successfully repaired your plastic gas tank.
Test your repair: After you let the repaired tank sit, fill it completely with water. The exterior of the fuel tank needs to be perfectly dry.
Verify if there is any leakage. Close the sides and bottoms of the tank when testing. If you do not find any leakage, your repair is a success!
Replace the gas tank, fill it with fuel and start your motor!