Sunrise
I was up early this morning and worked on testing bug fixes in the newly installed software from IBM at work. There are a number of such fixes and many of them are not simple or quick to test. I’m on my second coffee and still have several hours of work ahead of me before I can work on my diesel leak.
It is 10:30 and the effects of the previous cups of coffee have worn off, so it is time to fire up the hot water kettle and grind some more beans so that I can get through the morning.
Lunch
The fuel tank is made from LDPE, which should be “weldable”. The tank has the recycling number “4” stamped on, so I do know that this is the correct material. Antoine came by and we got the tank lifted on its side.
The leak location is not immediately evident, so it will take a bit more work to locate it.
I’ve removed all the tubing and sealed the tank openings using cling film and spare hose clamps. That way when Antoine returns with an air pump, we’ll be able to run a pressure test to find the leak.
Pressure testing the tank
Antoine came by with an air pump and soon we located the leak with the help of a spray bottle filled with water and detergent. The leak is so small that it is barely visible to the naked eye. But with the pressure of 400l of diesel and the rolling action of the boat at anchor and at sea it is evidently enough to leak a litre every two hours or so. The closeup to the right shows the leak location marked in green, it is in the top left cross component shown in the picture above.
Next steps
The first step is to seal the leak location by melting the plastic around it, this is possible with LDPE. My butane-powered soldering iron is the right tool for this job. But when I powered it up, it wouldn’t produce any heat despite refilling with butane. So, I got out my professional Hakko soldering kit and decided that ruining my soldering tip was a small price to pay. But before I could begin, I had to go to the local hardware store to find an epoxy or glue that was effective on LDPE – most adhesives won’t attach to this plastic due to its low surface tension. That trip took a long time, as it is a long walk out to the store. I wasn’t successful at finding an optimal glue; all of them had “Not suitable for PE” written in very small print somewhere on the back. The stores close at 17:00, so I couldn’t continue my search in the local chandleries, either.