Holding Tanks and Refrigerators

What do these two systems have in common you ask? I suppose you could say one holds your food while the other holds the waste products of your food. Both are systems on a boat that get a lot of discussion and attention from most boat owners. Both are systems that can cause lots of headaches and demand lots of our attention.

The holding tank on Beach House was the original from the factory and in a very strange place. Both heads are in cabins down from the main salon. The holding tank was a fiberglass tank installed under the seat at the dinette. Other than the fact that this might not be the most desirable location if odors develop, it means that the sewage must be pumped up hill from the heads to the tank, another less than ideal situation. 

This diagram, taken from Don Casey's article on installing a head, is a good approximation of the installation we are currently working on. The old tank has been removed and the process of installing the new tank and replacing all of the connections, hoses and valves is nearing completion. We decided to install the tank in a space next to the head, under the starboard bunk in the aft cabin. This makes for very short hose runs from the head to the tank, the thru-hulls and pump-out fittings and gives us easy access to all of the parts. We decide to use the Trident Sanitation Hose based on a lot of research on the most odor resistant hose for this purpose. The Y-valve is a Whale valve based on years of experience with this valve on our previous boat, Sea Trek. We had the tank custom made by Triple M Plastics in Maine to our specifications as to size and placement of fittings. They did an excellent job, and the tank is well-built and sturdy. Time will tell as to how well-built it is, and of course, we will report back. The current plumbing does not have a anti-siphon valve in the discharge. and we will add this and a larger vent on the tank than is normally found on most holding tanks. We would have preferred a 1 inch vent. but space constrictions kept this down to 3/4 inch. The tail piece on the head was cracked on our repair during the trip north, and although it has not leaked, it will get replaced. Since our forward head is now used exclusively as a shower, the head is disabled, but we can easily recommission it and add a small holding tank under the v-berth if we find we can't live without it.

We also decided to replace the fridge while we are able, even though this breaks our number one rule, "if it ain't broke don't fix it." The old fridge was a 3-way, using 110 volt, 12 volt and propane. We have never used the propane feature although the previous own did and liked it. The 110 volt worked well, but meant we needed to be connected to shore power or run the portable generator while at anchor. In our almost 20 years of living aboard, we have used a strictly 12 volt refrigeration system and found this to be the system we prefer. The advantage is that the system works off of one power source no matter what we are doing. If at the dock, the battery charger keeps the batteries up and the fridge happy. If at anchor, it is still running off the 12 volt system and the batteries can be recharged from the engine at the very least. Our decision to go with the Vitrifrigo C115 12 volt model was based on a lot of research and owner feedback. The unit actually has the same cubic feet interior as the original fridge, but the overall size of the box is much smaller. That means the cabinet has to be modified, but it is a simple modification. One big improvement will be the additional insulation added to the inside of the cabinet in which the fridge is mounted. Another bonus is additional storage space we have gained that we added under the new unit. The unit has the newer Danfoss compressor, and it does not add all of the heat that the old unit generated in the main salon. The Danfoss compressor is quiet, efficient and can be serviced just about anywhere without specialized parts. The power consumption is considerably less than the old unit, and this was a major factor in our decision.

Those are two big projects that should be completed within the next week or so. It is slow going when we have to work full-time. It always amazes me how work can really interfere with our boat time, but what can you do? Once these two projects are completed, we might just take some time and get the boat out on the bay. A new dinghy is to be delivered soon, and we will post on that after it arrives. A big rainstorm last night reminded us that the opening ports need to be replaced, so it looks like we need to start preparations and get the materials ordered. It just seems to never end, but it is, after all, a boat.