Permanent Plastic Gas Tank Repair

With our flexible PTFE Tech-Patches, youi can PERMANENTLY repair any damaged HDPE plastic gas tank Plus, PTFE Tech-Pastches will repair any damaged polypropylene gas tank and any nylon gas tank. PTFE is the chemical symbol for Teflon. Teflon is impervious or highly resistant to all types, grades and octane/cetane levels of gas and diesel fuels. There is one caveat. There must be excellent contact between the tank and the PTFE Tech-Patch. Since our patches are flexible, a curve is not a problem. Translation. There can not be a wrinkle or fold in the patch. Finally, the patch must extend at least three quarters of an inch beyond the damaged area all the way around. The bigger the hole the farther the patch must extend beyond the hole or crack. A video is at the bottom of the page.

Picture of our PTFE Tech-Patch

PTFE patch

In the picture, the brown area is the PTFE strip. This strip is bonded onto fluorosilicone (FVMQ). It is the side that has the brown strip that is bonded onto the tank.

Our fluorosilicone can be black or blue. Fluorosilicone has excellent resistance to regular gas, water, weather, dirt, grease, salt and most common chemicals. As stated, patches are flexible. That flexibility is essential to the success of patches.

How to permanently repair a plastic (HDPE, polypropylene, nylon) gas tank

The surface must be dry. There can be gasoline in the

  • If the problem is a crack, drill small diagonal holes on each end of the crack. This alleviates the problem of the crack being extended when gas is added or substracted
  • Surface preparation is critical. Rough the tank surface to below the “sheen”.
  • Clean the residue off with any cleaner that will not leave a residue. (Denatured or rubbing alcohol, acetone, soap and water, etc.). Let dry.
  • Saturate the area around the damaged surface and that damagaed area with the Poly Prep (PP). Let dry.
  • Spray the damaged surface and the surrounding area with the Activator/Accelerator (AA). Let dry.
  • Warm both surfaces, the patch and the tank, with either a hair dryer or heat gun. Warm to about 120 degrees F (49 degrees C) by temperature. By touch, warm to just below hot.
  • Apply the adhesive to the entire area of the patch, EXCEPT for diagonal corners, using small concentric circles. Full but not excessive coverage. If the hole is large, or the crack is wide, use the glue squeegee to spread the adhesive over that center area of the patch that will cover the hole or crack. Do not spread the adhesive that covers the outer perimeter of the patch.
  • Grab the adhesive free diagonal corner, apply tension and press the patch on the damaged area.
  • With your hand, smooth the patch from the center out and press down the edges.
  • Use the glue squeege to apply pressure from the center out, EXCEPT when there is an edge. Avoid applying pressure on an edge. That pressure on an edge could damage the patch.
  • By feel, check the temperature. You will know that the Polymer Bonding Process is working because the patch will be “hot” The temperature will reach to about 130 to 140 degrees F and that temperature will be maintained for minutes. If you do not feel the heat, your patch is not being bonded on. You are not repairing the tank! If the heat is not there apply, more heat from the hair dryer or heat gun to the patch until the patch gets hot.
  • Glue down the diagonal edges if necessary and run a bead of adhesive around the entire circumference of the patch. If you are not “plussing the patch (see below). Spray with the AA.
  • Visually inspect the patch. If there is a problem, apply adhesive ot the problem, press the patch down with the glue squeegee and spray with AA.

Repairing a melted John Deere plastic gas tank – An interesting case study that affirms how and how well PTFE Tech-Patches work.

In the recent past, John Deere had a problem with one of their models. In their design, John Deere placed their HDPE gas tank too close to the hydraulic system. Often, the heat generated by the hydraulic system would melt a section of the gas tank. Was contacted by a tractor owner that wanted to know if the he could repair the damaged area with a PTFE Tech-Patch. We said, “Yes, he could”, so he purchased a PTFE Tech Patch kit.

After he raised the gas tank two inches, the owner easily applied the PTFE Tech-Patch onto the damaged area. Unfortunately, even with the added distance, the heat melted the patch and SOME of the adhesive. Gasoline was dripping through the patch, while the PTFE patch remained bonded to the poly tank. To understand that statement, we have to explain how our PTFE Tech-Patches work. PTFE patches are flexible. Teflon is not. Why our PTFE patches are flexible is that the PTFE is woven. That weave leaves a way for the gasoline to excape, as happened on this case study.

However, the majority of the patch remained bonded to the HDPE tank. Why? Our SI adhesives are also impervious to all types and grades of gasoline and diesel fuels. In addition, the heat range of the bond exceeded the heat that melted the patch material, which is fluorosilicone and the SI adhesive which melts at about 280 degrees F. Fluorosilicone (FVMQ) melts at about 440 degrees F. The question that leaps out is how and why the PTFE remained bonded to the poly tank with an adhesive that “normally fails” at 280 degrees F?

Answer. The Process. Our SI adhesives are monomers. Polymers like PTFE, like HDPE are simply a string or repeating monomers. What the Process does is to create a sustained chemical reaction where the monomer of the adhesive becomes part of the molecular structure between the FVMQ and the PTFE. When that happens the monomer takes on the characteristics of the poly’s being bonded.

Final result:  When our client put on a third patch along accompanied by a heat shield, the patch worked perfectly.  The patches, applied properly, have always worked and there has not been a failure of the patch.

To purchase a PTFE patch, press the button below.

Purchase a PTFE Tech-Patch

“Plussing” a patch.

Often, patches are applied in environments with a high risk of abrasion or damage. When either of those risks are present we recommending “plussing” your patch. To plus a patch, you apply three of more coats of the SI adhesive on top of the patch, as follows;

  • Apply beads of the adhesive on top of the patch.
  • Spread the adhesive over the patch with a glue squeegee.
  • Apply adhesive and spread that adhesive two more times.
  • Spray the Activator/Accelerator.
  • If the risk is severe, add additional coats, spreading each coat, spraying the AA after each coat.

Once you “plus” a patch, that exterior of the patch will be as hard as most metals.

Note: After you “Plus” a patch, you can paint the patch.

Why our SI adhesives work when expoxies normally fail.

You will be using SI Black to apply the patch. Our SI adhesives are clear and dry clear. Black simply refers to the viscosity of the adhesive. We have SI Green, the low viscosity wicking grade adhesive. SI Blue, our standard viscsoity adhesive is twenty or more times thicker than the IS Green, making it much easier for technicians and novices to use. Si Black is used where more control is needed.

Our SI adhesives are premium, stable cyanoacrylates (superglues). Stable cyanoacrylates have a longer shelf life. All cyanoacrylates have excellent resistance to all grades and types of gasoline and diesel. Epoxies have almost no resistance to “aromatic” fues, i.e., the high octane gasolines and the high cetane diesel fuels. At best, an epoxy is resistant to standard gasoline and diesels. That means that if you try to fix a gas tank with an expoxy, it may work for awhile, but will almost always fail over time.

Tech-Patches are a proven technology! … and they are permanent!

Tech-Patches have been in use since 2017. Success rate on the patches is over 99%. Where there has been a problem, its usually been tthat he crack is in a fitting, or the tank was ribbed, or where there was not sufficient border area. If you are having a problem, please call 877 565 7225.

Getting into retail outlets. For PTFE Tech-Patches, we will be working to get into Advance, Auto Zone, NAPA< O’Reilly’s, Pep Boys etc. We have had to overnnight a number of patches because the tank had to be fixed. People need there cars. If you know anyone in the auto parts industry, let them know that the PTFE Tech-Patches are coming and that they always work. Thank you in advance.

PTFE application video.

Questions? Please call 877 565 7225

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