Water tanks and a hot day, be aware!!!

[cjmcfall]

I want to share something with you guys that is pretty obvious now, but I had never thought about before.

Last week, like much of the country, it was very hot in Michigan. When I arrived to the boat on Thursday evening the thermometer in the car was reading 101 degrees and the one in the boat was at 104.5 degrees.

I was doing some general clean up getting the boat ready for the weekend. I needed to fill the water tanks………..this is where the problem occurred.

Question: What happens when you fill your water tanks, with cold water, to full capacity on a very hot day???

Answer: Once full and capped, the water warms up and expands…………This could have been very bad!!! luckily I noticed it in time, before the tanks split and drained the water into the bilge. The tanks ballooned up and in the process raised the floor boards.

Solution: If you need to fill the tanks on a hot day, make sure you leave enough room for the water to expand.

All is good and no permanent damage.

[RAGTIMEDON]

Don't you have a vent? It would seem to me that it would be harder to fill the tank, harder to pump out the water when you use it, and would make your tank puff up and cave in as the temperature changes if there is no vent tube on the boat. I have aluminum tanks and am quite sure there would be a loud noise in the midle of the night as the temp drops and the water contracts. If it were my tank, I would find out if the vent is clogged, or if there were no vent I would put one in, "toot sweet." Drill a hole, insert a small thru hull, connect a piece of tubing to the side of the hull near the deck, and put a small thru hull there. Water coming out this vent hose also tells me when the tank is full, before I have overflow running all over the deck!

[SchoonerMISTRESS]

Hey Cjmcfall,
I am curious about your water tanks. Where are they located? Four of ours are under the cabin sole and one is under the saloon. While the one under the saloon could heat up to room/boat temp, I imagine the ones below the waterline should stay at water temp or close to it. Right now our water temp is about 85 degrees. Wouldn't this keep those tanks closure to that temp vs air temp? Additionally, our tanks are all vented, although there is one that is being rather fussy about this and this makes it harder to draw on then any of the others, we also have an overflow that leads to the head. Any overflow ends up in the head sump pump.
I do appreciate the heads up and will make a point to mention it to the Captain this evening.
Thanks!
Kathleen
aboard
Schooner MISTRESS

[Sapperwhite]

Tanks need to be vented to accept volume fluctuations due to temperature. Change in volume is what makes water break concrete when it freezes and thaws. It will do the same thing to your tank when it heats and expands with nowhere to go. Make sure your vent are clear, sometimes insects build nests in there, and eventually block the vent line.

[sailingdog]

If your tanks aren't vented, I can see this being a problem. Even a tank with a blocked vent (insect nest, spider webs) would probably flush the vent line before rupturing the tank. Wasps and spiders aren't using industrial grade materials to block the vent, and as such their nests/webs are generally easily removed, and a flush of warm water would probably be sufficient, where low pressure air is not.

[USCGRET1990]

Originally Posted by sailingdog

If your tanks aren't vented, I can see this being a problem. Even a tank with a blocked vent (insect nest, spider webs) would probably flush the vent line before rupturing the tank. Wasps and spiders aren't using industrial grade materials to block the vent, and as such their nests/webs are generally easily removed, and a flush of warm water would probably be sufficient, where low pressure air is not.

Apparently you've not heard of the African epoxy spittin beetle that is now affecting America...

[sailortjk1]

I think I have seen those here on the Great Lakes.
Very nasty critters. Will block any vent.