Repairing a Plastic Fuel Tank

     I inherited a 1980s Craftsman leaf blower that I used for a couple years but then it started to leak fuel. The fuel leak appeared, at first, to be a rotted fuel line (caused by ethanol in the gas), which I replaced. But it still leaked. Then I thought the replacement fuel line was too small in diameter and it was leaking around it. But that was not the case.  What was wrong now was that the fuel tank itself had split on the bottom seam, which you can clearly see in the image below.

    It might be possible to fix this with some sort of epoxy, but I have found in many instances that a surface coating of epoxy won't last long. Sometimes it peels off and sometimes the vibration of the engine just makes it crack in the same place. What needs to be done is to reinforce the strength of the seam and then seal it.

    Back in 2009 I found a tandem kayak in a wood line on government property that I had legal access to. I took the kayak home, cleaned it up, and found that some numbnut had hacked into the kayak with a hatchet for some reason. I looked up the kayak make and model on the Internet and a new one was $1,700 so I figured if I could repair it for cheap I would do it. Again searching on line for ways to repair kayaks, I came across a product called a KC Welder (possibly Kayak and Canoe welder?).

    This kit cost me about $40 I think. Inside the kit is a heating wand or paddle, some plastic strips (welding rods of a sort), and some aluminum screen material. With this I repaired the big kayak and have been using it for 15 years without any issues at all. This kit allows you to make very strong repairs.

    The wand works like a soldiering iron or wood-burning iron. The metal parts get VERY hot (yes, I have burned myself repeatedly) and you use the paddle-shaped tip to do the work. For this repair, I cut up two strips of screen to lay over the crack and then melted them in by pressing the paddle down on top of the screen. The heat of the wand transfers to the screen and the screen melts into the plastic part you are repairing, as shown below.

    I move the wand tip around until the entire piece of screen has been melted into the plastic. This reinforces the plastic along the split and prevents it from widening at the split and also  keeps the split from getting longer. Once that is all done, I apply filler plastic on top of the repair as shown below.

    Ideally, I try to scavenge plastic from somewhere on the piece I am repairing so that there is perfect compatibility on the repair, but there wasn't anyplace that I could remove plastic from this piece. So instead, I used the plastic sticks that came in the kit and melted them and mixed the two plastics together and hope that I get a "alloy" that works. In the many years that I have been using this kit, I have not yet had a plastic "organ rejection". But these plastic repair kits do come with rods that are specific to the type of plastic from which your kayak is made.

    So, now all I have to do is put it back together, fuel it, and see if it still runs.