Day 442 Engine Fan Nav Seat
Most boat's engines have salt water cooling, which, in effect, pumps water from the ocean into a heat exchanger along with antifreeze laden fresh water in a closed system which in turn  goes through the engine.

As mentioned earlier in the site (quite a few times!)  we have a completely closed system that uses the hulls heat dissipation ability into the ocean for cooling. In either case, the engine's surface is still very hot because there is no airflow across it in an engine room. That heats up the engine room, then the rest of the boat after a while. We decided to resolve this problem with a fan.

Originally we were going to put a fan on the water pump shaft, where it was when we purchased the engine, but the second alternator would be in the way. Because our New Yorker car is on it's way to the scrap pile, we decided to yank it's electric fan and use it.

    Gena made a frame that would carry the fan assembly, and mount it to the bulkhead ahead of the engine. The fan consumes 20 amps but the small alternator will keep up with that no problem.

The  real issue is ducting and a good seal onto the hatch above.  We channeled off everything forward of the last frame under the pilot house, and I made a vent for intake. The external vent idea was a no go, so leaving a hatch open somewhere in the boat will allow all of the air the engine needs to cycle through, then out the aft.

Before the fan can be tested, the hatch insulation and covering must be put on, so that's about it on this!

Today I was in the mood to start the seat for the navigation table in the pilothouse. I have pre-designed it and animated it with several corrections along the way. The support length and propping position was varied so it could clear the seat when folded. Once I was confident I had the right lengths, I began. These things always look good on paper though!
 If you watch the video, you can get a basic idea of what it does. Theres also a folding seat back that goes over it.

Because solid rod on the prop arm would be heavy, I went with some left over hydraulic pipe and capped the end with short slug pounded in.


The stool seat part will be stolen from the stool I use up in the studio. Back to the old kitchen chair I guess
Just a little note on this horn unit. A friend gave us this a long while back, not sure where he got it from. It's a very loud beeper horn thing with 3 different types of sounds. The way the thing was witred was no good for our application though. All 3 inputs were on the negative side.

I put in transistors to invert the inputs to positive and Gena installed it. The whole thing can be turned off, but will be used while at anchor mostly. I wanted it for the sonar alarm, the radar proximity alarm, and one off my custom dash interface.

Once in, I was looking for the wire for the radar alarm and referred to the manual for it's location on the unit's back panel. There it is, and, oh no! It's a negative going output! SO now I must pull the unit, take out one transistor to return it to it's original state. Guess I should have checked that before!

Day 442:
 7 hours: Made fan mount, painted, started nav seat

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