Filling Watertank

[Albanach]

When I filled up my freshwater tank recently, I waited for the water to exit the vent as a sign that the tank was full and turned the hose off.
To my surprise, 30 minutes later, the bilge pump started. I then emptied over a bucket of water out of the bilge.
Is there an additional overflow vent/pipe that drains into the bilge? This makes it extremely hard to judge when the tank is full. Any suggestions?

 

[BLUTE]

I listen to the change in tone when filling the tank ........you can also lift up the forward matress an look into the tank to see if you need to top it up.....
my 310 also drains to the bilge if i over fill the tank..:dance:

 

[paulj]

Me tooo


paulj :troll:

 

[So Cal Gary]

What's happening is that when the tank fills it bulges the top of the tank up--the large inspection cap seal then leaks (as shown on Paul's photo). One thing I did that really helped was to add a 2 x 4 across the top of the tank to help the bulging. I also fill the tank very slowly and as soon as I hear gurgle at the vent in anchor locker--I stop filling. But the 2 x 4 really helped.

 

[Albanach]

Thanks for your suggestions, folks. Shall listen to sounds next time. Hate getting my head under that mattress, due to old neck injuries from surfing.

 

[Witzend]

Use a boat hook to prop the mattress up.

 

[Chris Connor]

What's happening is that when the tank fills it bulges the top of the tank up--the large inspection cap seal then leaks (as shown on Paul's photo). One thing I did that really helped was to add a 2 x 4 across the top of the tank to help the bulging. I also fill the tank very slowly and as soon as I hear gurgle at the vent in anchor locker--I stop filling. But the 2 x 4 really helped.

My 310 potable water tank vents to the chain locker forward. When I am pressing up the FW tank I always check my vent is clear and slow down the rate of filling when nearing the top of the tank. You can put a lot of pressure on your tank by allowing a two or three foot head of water up the filling tube. This is how we pressure test tanks in large ships!

When I was working in large ships in St John's Newfoundland we had to be very careful topping up tanks in sub zero weather. On one occasion an ice plug formed in a vent which sealed the tank. You would be shocked to see what city supplied 60 psi water pressure can do to a steel tank. It would destroy a plastic water tank like ours.

I installed a tankwatch system on my potable water tank (mostly because I have an electric toilet that uses water and have to monitor it closely). When filling, I always have someone monitor the tankwatch and when it hits full, I slow the rate of filling and listen to the vent in the anchor locker. When air stops flowing - I stop filling.

Regards

Chris

 

[Chris Connor]

The pictures of my installation for the tankwatch system are on this forum if anyone is interested.

Regards

Chris

 

[Witzend]

How about using a whistle stuck in the vent. Yoe would have to cobble up some adapters to make things air tight. Iit would work the same way your oil tank for your home heating does.

 

[Albanach]

Don't know the oil heater whistle - disconnected ours some years ago when it became uneconomical. But I like your innovative approach and shall give it some thought. Not sure if the pressure would be enough. Also, my hearing is still extremely good (at least something is still working ok).

More than I can say about those fishermen buzzing around in kayaks amongst the moorings with ipods or similar glued to their ears. Am trying to design a pedestal holder for my air horn.

 

[Witzend]

To get the pressure up the fill hose would need to be sealed around the deck fitting. Some high density fome cut into a donut shape maybe.