Day 318 Septic Tank
Once upon a time, sailors, when confronted by natures "one" or "two", would use their ensuite bucket and immediately toss it over the side. Simple yet effective. After a couple hundred years we have become somewhat more refined in our ways and this requires a slightly more complex solution.
Gasket on the septic tank

The pumpout hoses
The septic tanks fittings are shown in place, as described on day 317. Still missing is the level indicator (underway!)

Gena cut the rubber gasket for the access hatch to a perfect fit. She must have done this before! The access hatch is good for holding fittings through while tightening them from above, as well as cleaning out the tank from time to time That is if we can find someone who'll do it lol.


The pump-out hoses have been inserted ( photo left ) and cut to the right length. They are the rigid type so they won't collapse when under suction from powerful marina pump-outs. ( We have heard rumors! )

The real trick is how to measure level in this tank? The sensors we used on the plastic tanks don't work on metal, mechanical/resistor sensors will jam and rust, visual tube types are fouled by black water.

A float switch would be good to show when the level is up to 75% say, but this doesn't reveal much when it is below that level. If we were sailing into a pristine area where pumping out is prohibited and it took 4 days to get there, finding out our tank is 75% would limit our time to stay.

I saw no other than to make a level indicator. It is comprised of several glass reed switches encased in a waterproof tube. A doughnut magnet slides up and down the tube as levels change which activates the reeds sequentially.
Simple enough, but two problems arose:
-When the magnet is between reeds, sometimes neither would be active, and other times 2 at the same time.
-As the doughnut shaped magnet passes over the reeds, the poles change creating a null area, thus releasing the reed switch in that position.

Some electronics is in order! I am so glad I learned to program microcontrollers. The unit ( just past the testing phase ) software and schematics for the pair of PIC16C57C microprocessors is here.

As can be seen in the photo, the end of the pipe is plugged off. I used some Goop and the a soldering iron to weld the plastics together. The plastic pipe has a threaded section on the end, so we just adapted it up to the size for the hole in the tank, then to a fitting large enough the house the board for the sending unit.
Each of the reed switches are wired along an old fiberglass CB antenna core up to the board. This means the "reed-stick" can be removed for inspection without the mess of removing the whole pipe.
I plan to put a small amount of mineral oil in the bottom of the pipe to trap any accumulated moisture that may get inside. (Nothing can seal perfectly, right?)
The small sender board will transmit data to a display panel unit via only 2 wires which also powers the unit up to 20feet away! (Best to keep wire count to a minimum)
I have designed the display to fit behind a standard house light switch panel. (stainless of course! hehe)


The rollers for sliding doors

Recessed FG panel in place



The photo to the left shows the roller assembly for the sliding doors in the pilothouse. That is a screen door roller which is exactly 1/4" wide, perfect for the 1/4" track laid yesterday. Height had to be precise and the screw/nut was countersunk for appearance. I rolled the frames along the track and they went smoothly.


The dry locker side panel needed to mounted so Gena finished her day with that. We have since added a nice handrail going up parallel with the steps. According to various sources, too many hand rails are never enough, so we're heeding their advice. Overhead handrails are reputed to be a bad idea as, after a while, stresses from holding up ones arms can take their toll.
The edge of the panel runs in to the routed oak providing a smooth transition and no catch areas for clothing.
All of this woodwork will need to be put on hold as the weather is allowing us to prepare for the deck coatings etc. A bowsprit still needs to be made, stainless polished, welds flattened, and vent holes cut.






Gena got an early start by finishing the autohelm rudder filling and putting on some gel-coat. After some sanding, a second coat and blue below the proposed waterline will be added. We had plenty of experience with gel-coat on our small boat. It's ok as long as there is no flexing.


Day 318:
9 hours - Mounted fittings on septic tank, entry panel, rollers, test fit level sender.

to DAY 317

More than radios!

to DAY 319