Sunday, January 10, 2016

Fuel Tank Completed – Sender Plate & Sender Installed With Modification

One of the tasks that needed finishing but has been put off for the longest time is installation of the sender plate and fuel level sending unit.  For the last month or so I’ve been putting off installing the sender plate and sending unit on the fuel tank. This needs to be done during “warmer days” because it is best if fuel tank sealant cures with warmer temperatures … but because of the hassles involved with using the fuel tank sealant, have been putting this task off. The last few days have been in the 40’s here so decided it best get this task done now because the temperatures are about to take a long term dip. To enable the fuel tank sealant to cure properly, a third 100 watt light bulb was added in the hot box so the temperatures should stay in the mid 60’s or higher during the overnight hours. The hot box should be able to stay warm enough until the big temperature plunge hits in a couple of days and by then, the tank sealant should be cured nicely.

I can honestly say, by painting the tank before ALL the fuel tank sealant work was completed has created a lot of extra work. If I had it to do over, would do all the fuel tank sealant work first, then mask and paint the tank. Masking around the sender plate and sending unit was a very time consuming pain, plus a lot of extra care is needed to prevent the fuel tank sealant from getting all over the tank when it is applied. But the task was completed, along with a modification for grounding the sending unit.
Another task completed, fuel tank now has the sender plate and sending unit installed completing the fuel tank assembly. Note: The wire I’m holding is not in the plans … it is a ground wire modification for the sending unit.

Because fuel tank sealant is used exclusively during construction of the fuel tank, a very small number of RV-12 builders have discovered flaky fuel level readings attributed to poor grounding of the sending unit ... which is obtained through the fuel tank sealant covered screws securing the sender plate and sender onto the fuel tank. To insure a solid grounding of the sending unit, decided to make a preemptive strike by attaching a ground wire directly onto the sending unit. After a few days of cure time, the tank will be ready for pressure testing whenever I feel up to the task.