INSTALLING A SECOND HOLDIDING TANK IN A F36

gjrylands · Post by **gjrylands** » Sun Nov 09, 2008 11:21 pm

I have a 79 F36 Trojan. I installed a second 28 gal. holding tank in a dead space I found working on another project. It is under the cabinet & stove in the galley. I was able to remove the shielf and floor of the cabinet, (The shelf is held in with about six or eight screws and is easily removed. The floor of the cabinet is a little more difficult. It was glued and stapled when it was made. I was able to get it out, but not perfectly. Some of the plywood remained glued to the cabinet. This wasn't that much of a problem. It only meant that the floor of the cabinet would have to be replaced and the part still stuck to the frame would have to be cleaned off. The floor is 3/8 plywood. I also removed the range to get extra working space. This exposed two stringers.. The inside stringer sat higher than the outside stringer. I fastened a cleat on the side of the inside stringer set at the same height of the outside stringer. Before I mounted the plywood, I fastened 1x1 pieces of wood to lock the holding tank on the plywood. I then painted everything with a couple of coats of battleship gray. I mounted hardware to hold the 1"stainless straps that I used to hold down the tank.I then mounted the finished plywood to the stringers. (One side of the plywood sat on the cleat, the other side sat on the stringer.) Once the platform was complete, It was a simple job to mount the tank. I added a new waste deck fitting for the new tank and installed a Y valve to direct the waste to the desired tank. Reinstalling the range, cabinet floor, and shelf completed the job. I screwed the floor of the cabinet to keep access to the holding tank.
Gerry

Danny Bailey · Post by **Danny Bailey** » Thu Nov 13, 2008 9:16 pm

Gerry, Just noticed your post....I was in the same area on my 1980 F-36 4 years ago when I had to replace both aluminum fresh water tanks. I cut out a piece of the floor to get access to the LH tank. There is a large un-used space outboard of the water tank. I've been thinking about putting a holding tank under the cockpit floor where the aft aux gas tanks would be if I had any. How's your system working with the added capacity?

gjrylands · Post by **gjrylands** » Fri Nov 14, 2008 1:59 am

The second holding tank more then doubled the capasity. I also added an Acuguage Tank Monitoring system on the tanks to take the guess work out equasion. I put the Y valve under the galley. When the first tank is full it's a simple job to remove the steps in the hall and reach in and switch tanks. (The steps lift right off) When the second tank reaches 3/4 full I know a trip to the pump out is in order.

What's nice about the Acuguage Tank Monitoring system is that there is nothing inside the tank to get fouled up. Everything is glued to the outside of the tank and is sensed through the tank. (The system will not sense through metal tanks) I installed the monitor in the head, so checking the level is easy while your thinking about it.