Water tank leaks...from the top

[canuck]

This problem with leaking through the access port is not confined to the 34. A friend of ours has a 42 and had the same problem. He solved it by securing the port with quick cure 5200. In as much as I don't have an access port in the stern tank (or do I?), this is the route I will go.
I enjoy the time spent reading the forums for the 36 and 42 et cetera. Similar problems and then some! 

[Ron Hill]

Can : 3M5200 is too radical an approach to fixing that leak!!  As I mentioned before the cleanout threaded plug is a tapered thread.  I use "pipe dope" thread sealant to seal those threaders.
 
Someday you just might want to open that plug and will have "one hell of a time" if you use 5200.  Beside the only time the water comes out of those plug threads is when you OVERFILL that tank.  As far as I know the aft tank has no cleanout threaded plug. A few thoughts.   

[Jeff_McKinney]

I've had the forward water tank leak from the clean-out port and applied 2 turns of teflon tape with decent results. I also listen/look for the water gurgling in the anchor locker as I'm filling. As Ron noted, if you don't overfill it the problem is minimized or eliminated.

If you are not sure how close to full you are and don't have a tank sensor, lift the access panel (under the v-berth mattress in the Mk II) and you can see for yourself. Unless you have stuff stored below in the drainage pathway, any overflow goes to the bilge - messy but harmless. Running the galley faucet or some other discharge for a couple of minutes will also draw it down.