How to Fix Leaking Water Tank

[mlitzkow]

Our water tank leaks when it's filled more than about half full. The S2 manual states that the tank vent terminates in the anchor locker, but there appears to be no such connection between the tank and the locker. There is a fitting with what appears to be some sort of venting valve, but not connected to anything. We were hoping that this might be the problem (water leaking out of the unterminated vent when heeling). However, we plugged off all inlets and outlets and tried to pressure test the tank, but never were able to build up any pressure at all. Thus it looks like the tank has some sort of serious leak - maybe a burst seam or corroded through. The tiny parts of the tank visible through holes in the bulkheads don't show any corrosion though.The tank is quite well buried under the V-berth. It appears that some serious fiberglass surgery will be required to even see what is wrong. We would very much appreciate hearing from anybody else who has tackled a similar job in an S2. How much cutting was actually required? Will the tank fit through the door to the V-berth even after getting it loose? What was the actual cause of your leak? Did you repair the tank or replace it? What's up with the missing vent line?Any advice appreciated.

 

[rapport]

tank leak

There is a tank vent in the forward v, look under the forward board under the cushions you should see the top of the tank the center line.The tank should have a threaded port with a fitting usually a 90 degree a conpression fitting to 1/4 " nylon tubing. this tubing should be routed to the anchor well, terminating at the highest part of the bow. '

 

[mlitzkow]

Further questions

Thanks for your response. Under the board under the v-berth cushions there is a horizontal plywood piece fiberglassed into the hull. The actual tank is under that. Only very little of the actual tank is visible, but there is a small hole in the plywood at the starboard aft corner of the tank. Out of that hole sticks a fitting with a small spring-loaded ball inside. This fitting is not right angle as I might have expected, and has no tubing of any kind attached. However, the only explanation I can see for it is that it's intended to be the tank vent. Also, there is no hole into the anchor locker where a tube ever could have gone. My original plan was to attach a tube to the fitting, route it properly to the anchor locker, and be done. However, since I cannot pressurize the tank with this fitting as well as the inlet and outlet ports blocked off, I think I have a tank leak. Does this make sense to you? Have you ever had to actually remove one of these tanks?thanks.

 

[Rapport]

Leaking Water Tank

I have not removed a water tank. Your vent plan is sound. The check valve might allow air in but you need to let air out when you fill a tank, since my water tank fills from the starboard side near the bottom. S-2 uses good engineering so the lack of a proper vent is confusing. My hull was made in 1983 hull # 433 that had a tank centerline vent located at the bow bulkhead. THe vent line goes through a small opening in the vee tank bulkhead on the port side. My boat allows the lower vee cabin fill piece to be removed with full axcess to the bottom of the anchor well and the ability to see the vent line going to the bow,entering at the bottom of the anchor well at the bow, and ending almost at the deck joint. Sorry about a bad design of a non-centerline vent. I have never placed pressure on this tank, only used water to the top of filling port, resulting at most 1 psi pressure. ( Water tanks are not designed for pressure). Does water leak out of the tank or could here be an other vent opening? I have only seen the fitting ( if brass ) you have on your water tank used in the fuel tank to prevent back flow and is the first part of the fuel line to clog. I can't sent photos till my next trip to the boat due in april.