How To Fix Common Gas Tank Repair Problems

Gas Tank Repair

Instructional videos at the bottom of the page.

There are two obstacles that are not usually considered in the repair of a gas tank. These issues are:

  1. Gas will eventually eat through most adhesives. Gas, oil, nor any hydrocarbon will not have any effect of our SI Structural Adhesives … ever. We have an ongoing lab test where bonds have been immersed in gasoline for a number of years. Bonds have retained 100% strength.
  2. Gas tanks, especially plastic gas tanks, expand and contract. Cured adhesives do not expand or contract. When gas tanks expand, cured adhesives crack. Gas then leaks. A repair on any gas tank, but especially plastic gas tanks needs to be able to handle the expansion and/or contraction that comes from changes in temperature. Tech-Patches expand and contract with the substrate.
    There is a video at the bottom of the page showing how to apply a Tech-Patch to a plastic gas can. Since 2017, when the video was shot, that plastic gas can has been put in the sun on a hot day a couple dozen times. Of course, the tank ballooned. Since Tech-Patches are bonded on, the patch expanded and contracted with the temperature. Not a drop of gasoline has leaked … ever. Since Tech-Patches are bonded on with our patented Polymer Bonding Process, they are permanent.

Gas tank problems:

There are three possible problems with plastic or metal gas tanks.

  • Pin hole leaks
  • A crack in the tank
  • A hole in the tank.

We will cover how to repair each problem for both plastic and metal gas tanks.

Issues of Concern:

Whenever there is a crack in a plastic or metal gas can, you need to drill a hole at each end of the crack to prevent that crack from widening. If you do not drill a hole at each end, the crack will lengthen and leakage will result.

When there is a problem with a metal tank, there is often a loss of substrate due to corrosion.  Ideally, that substrate needs to be rebuilt to the extent possible.  Our Filler, used in conjunction with an SI adhesive, will rebuild that tank and the new structure will not corrode. A Tech-Patch must then be applied to the metal tank..

Tech-Patches

For plastic Gas Tank Repair
Repairing a Plastic Gas Tank with a Tech-Patch and our patented Polymer Bonding Process (Process) is a quick, easy and permanent task.

Tech-Patches are made of one of the chemical and weather resistant polymers made. As discussed above, a patch’s flexibility is a necessity in repairing gas tanks. Items needed for the repair of a plastic gas tank are listed below. At the bottom of the page there is a button that will take you to where you can buy a Tech-Patch Kit.

  • A Tech-Patch, sized to fit the problem. Patches come in sizes from 2″ x 3″ to 6″ x 24″ and can be cut to fit your problem.
  • A Poly Kit (or higher) which contains:
    • SI Black, our thicker structural adhesive. Thicker to give you the control needed to apply a Tech-Patch.
    • Poly Prep, an adhesion promoter for polymers and poly plastics.
    • An Activator/Accelerator (AA), the AA is critical to the Process.
  • A heat gun, hair dryer or other heat source.
  • Glue squeegee
  • Sandpaper
  • Instructions
For Metal Gas Tank Repair
  • A Tech-Patch sized to fit the problem.
  • A Starter Kit or higher
    • SI Black
    • Our standard Activator/Accelerator (AA)
  • Glue squeegee
  • Sandpaper.
  • Instructions

Steps in Repairing a Metal Gas Tank

Repair steps:

  1. Surface preparation is critical.
  2. CRITICAL. If the problem is a crack, drill a small hole at each end of the crack.
  3. The damaged surface needs to roughed to a polished surface. Start with a medium to coarse grit of sandpaper and finish with a 400 or 600 grit.
  4. Make sure surfaces are clean. Use any cleaner that will not leave a residue.
  5. Wipe the surface with a soft cloth.
  6. Spray the surface with the Activator/Accelerator (AA). Let the AA dry.
  7. Apply SI Black (is clear and dries clear) to the matte side of the Tech-Patch except for diagonal corners. Apply liberally, especially covering the area of the crack or hole.
  8. Grab the adhesive free corners of the Tech-Patch.
  9. Press the Tech-Patch onto the problem area. Grab will be quick.
  10. Press the edges of the Tech-Patch down with your fingers.
  11. CRITICAL use the glue squeegee to apply pressure from the center outwards on the Tech-Patch.
  12. Glue down the corners with the SI Black.
  13. Apply a bead of the SI Black to the perimeter of the patch. Spray with AA.
  14. Visually inspect the Tech-Patch to make sure there are no problem areas.

Steps in Repairing a Plastic Gas Tank

  1. Surface preparation is critical.
  2. If the problem is a crack drill a small hole at each end of the crack.
  3. Aggressively rough the surface with medium grit sandpaper. 
  4. Clean the surface with any cleaner that will not leave a residue.
  5. Wipe the surface with a soft cloth.
  6. Saturate the prepped area with the Poly Prep.  Let the Poly Prep dry. Once a poly is primed with Tech-Bond’s Poly Prep, that poly is primed forever.
  7. Spray the prepped area with the Activator/Accelerator (AA). Let the AA dry. Once sprayed with AA, you have an hour of work time.
  8. Warm the prepped surface with a heat gun or hair dryer.  Warm until the surface is just below hot, approximately 120 degrees F. 
  9. Liberally apply SI Black to the matte side of the Tech-Patch except for diagonal corners. Make sure edges of the crack of hole will be covered with the SI adhesive
  10. Grab the adhesive free diagonal corners, apply tension and press onto the problem area of the tank. Grab will be quick.
  11. Press the edges of the Tech-Patch down with our fingers.
  12. CRITICAL. Use the glue squeegee to apply pressure on the Tech-Patch from the center out.
  13. Glue down the corners with the SI Black.
  14. Apply a bead of SI Black to the perimeter to the perimeter of the patch. Spray with AA.
  15. Visually inspect the Tech-Patch for problems.

Press one of the buttons below to choose your Tech-Patch Kit

Choose the size of your Tech-Patch, then the type of Tech-Bond Kit. For metal gas tanks, choose a Starter Kit. For a plastic gas tank, choose a Poly Kit.

Commercial Grade XT2 Tech-Patch – two millimeters thick. Industrial Grade XT3 Tech-Patch – three millimeters thick.

For Holes In Poly Tanks

For holes in poly tanks, Tech-Patches are recommended. Please see Tech-Patch instructions.

Scroll to top