February 27, 2020

Scupper 251

Thursday

First thing, I lowered the final pair of batteries from the cockpit into the cabin, and then got them in their box and into the engine room, where I secured the batteries and box as I’d done with the previous sets.

Grateful to have that behind me, for the moment I turned to another pressing task:  the tiller.  After two days in the clamps, the epoxy had had more than adequate time to cure and hold the tight curves, so I released all the clamps and removed the partial blank from the jig.  The epoxy didn’t stick to the plastic blocks, so the tiller released from the jig without much effort.  Once I had the blank out, I cleaned up the wide surfaces with a sander to prepare for the additional laminations.  Then, the blank fit right back into the jig, ready for the next glue-up.

Starting with the newly-prepared top of the blank, I glued up another set of teak laminations (I think there were 8 this time) to bring the tiller blank up to the desired proportions.  This was a lot of laminations to do at once, but it worked out, not without alacrity and effort, however.

Before getting back to the engine room and batteries, I took care of another small item on the to-do list and installed a new padeye in the cockpit, which the owner had requested for securing a harness.  I always like these investment-cast 316 padeyes for such uses, and as per usual I installed it with machine screws through tapped holes in the cockpit well, lots of sealant, and a fiberglass backing plate.

I spent the rest of the day working on the final wiring in the engine room, choosing to work more or less from starboard to port to finish up what was needed.  I started with the engine battery charger, which required positive and negative cables (in this case the positive cable ran to the first set of batteries on the starboard side, and the negative all the way to the far port set).  I followed the general guidelines set forth in the instructions from the electric motor manufacturer, which differed slightly from the charger’s documentation but in a more conservative way, incorporating a fuse (50 amp) in the positive side, and a larger wire gauge.  I also installed a battery temperature monitor required for the charger, which also led over to the eventual negative terminal at the far port side of the 48-volt bank.  For now, I left those negative-terminal wires detached pending final wiring on the rest of the bank.  I made up the 2/0 cable leading from the bank’s positive terminal to the system fuse I’d installed during an earlier wiring phase, and connected the positive charger wire to the battery as well.

Continuing, I made up the jumper to connect the first set of 6-volt batteries together, then another jumper over to the next battery pair.  I chose the routing as needed to minimize strain on the terminal ends, as the stiff cable wasn’t prone to tight bends.  Each set of batteries would be connected in this way:  positive to negative, in series, across the line.

For now, however, the day was done, and in any event I had run out of the 5/16″ battery lugs I needed to finish the cabling (I’d ordered more early in the day), so I’d continue with the project as soon as those arrived.

Total time billed on this job today:  8 hours

0600 Weather Observation:  33°, cloudy with light rain showers.  Forecast for the day:  Heavy rain and wind, 38°