Tank Sealer is formulated and designed to stick to a bare surface that has been prepped with KBS Klean (cleaner) and RustBlast (acid etch). With that in mind, it is always a good idea to strip out the previous sealer with KBS Strip.
Directions for Stripping Out Old Tank Liner
Use KBS Strip for the most effective removal of an old failed coating. Pour some KBS Strip into tank and carefully rotate tank to allow contact with all sides. It may take multiple applications of KBS Strip to finish the job completely. Old Sealer may come loose in big chunks or small pieces so use a long tweezers-type tool to help remove it from the tank. After stripping is complete, rinse tank generously with water and proceed with the KBS 3-Step System for Fuel Tank Preparation & Sealing. (NOTE: When stripping a Fiberglass Tank, surface contact with the stripping agent should be kept to a minimum to avoid the attack & weakening of the fiberglass resin.)
After you have the previous liner out of the tank, you can proceed with the KBS 3-Step Tank Sealing System.
Please check out the Complete Tank Sealer Directions.
There are thousands of different types of plastics and polyethelynes in use today and they continue to change every year. Because there are so many out there, it is impossible to test all of the plastics and polyethelynes for adhesion and compatibility. Therefore, we can not completely recommend our tank sealer kits for plastic or polyethelyne tanks.
What we have found over the years is that many plastic and polyethelyne tank owners are so desperate that they have been willing to give it a try regardless of the results. The surprising thing is that most, but not all, have great results. The success is due mainly to the fact the more porous the plastic or polyethelyne, the more it leaks. But this also means the more porous the plastic, the better the gas tank sealer can stick because our Tank Sealer loves porous surfaces.
In conclusion, we can not recommend our tank sealer kits for plastic or polyethelyne fuel tanks. But, if you are desperate, you can certainly give it a shot.
==== TANK SEALER DIRECTIONS AND ADDITIONAL INFORMATION: ====
You can find complete directions for the KBS 3 Step Tank Sealing System here: http://www.kbs-coatings.com/tank-sealer-directions.html
You can find instructional videos for the KBS 3 Step Tank Sealing System here: http://www.kbs-coatings.com/instructional-videos.html#ts
You can find Application Flow Charts for the KBS 3 Step Tank Sealing System here http://www.kbs-coatings.com/tank-sealer-flow-chart.html
You can find How-To's for the KBS 3 Step Tank Sealing System here: http://www.kbs-coatings.com/how-to-use-kbs-coatings.html
You can find a Fix-It Guide for the KBS 3 Step Tank Sealing System here: http://www.kbs-coatings.com/fix-it-guide-tank-sealer.html (Always a great idea to familiarize yourself with it before beginning your project.)
KBS Coatings - Rust Stops Here