Sunrise
The winds have subsided, and I had a good night’s worth of sleep. I’m ready to repair my diesel tank, but first, I need my caffeine fix.
Work on the tank
This is going to be a difficult repair. There are very few adhesives that will stick to LDPE, and I haven’t found any on the island. I’ll do one last walk through the chandleries in the hope of finding a tube. Or, as a second option, some xylene or toluene (which dissolves LDPE).
Welding (soldering) the leak
I am going to use my Hakko soldering iron and accept that I’ll ruin the tip when I heat the plastic with it. I’ve shaved off some plastic from the very long rear tank filler where it won’t be missed. I’ll use that to add some structural plastic over the area of the hole. LDPE melts at 115°C, and the Hakko temperature can be adjusted to that range. The flash point of diesel is just over 50°C, and the autoignition point is 210°C. But the material of the tank is quite thick. I’m only heating a very small area from the outside, and I’ve cleaned up any diesel residue around the repair spot, so I will be quite safe. On the other hand, the recommended LDPE welding temperature is 270°C, and I don’t want to reach that, considering the autoignition temperature! This diesel tank repair might get dangerous.
Unfortunately, the melting part of the operation is also going to be the most important structural one, considering I have no good adhesive to apply over the leak area.
TAP Poly-Weld Adhesive
I knew from the start that my odds of success were going to be low. Nonetheless, I worked my way through the stores and chandleries in search of an appropriate adhesive. This specialty item was not to be found, every glue I looked at stated: “not for polyethylene“. I dropped into a small store right by my dock and was delighted to find this adhesive (even though the little 30g dual tube cost over €60). I also bought a little flamethrower for Creme-Brûlée and my sous-vide steaks; this is needed because the instructions on the adhesive include “flaming” the area to be glued. While looking for a link to the product, it seems that it has been discontinued, but detailed application instructions are available here.