water freezing in water cock

[robpols]

I am leaving my boat in the water for the first time this year.
I have drained the engine, toilet and water system. My question is is I am running a serious risk with the water that is still in the intake sea cock of the toilet and engine cooling water intake cock. I know that tis is just a few inches of pipe. If it is a probelem what is the solution?
Regards

Rob

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[gunnarsilins]

I cannot judge...

...if the temperatures in your area can get low enough for a sea cock to freeze.
Even if the air temperure is well below freezing point, the warmer water will probably keep the temperature in the sea cock high enough.
In Stockholm, where I keep my boat afloat, I have noticed that as long there is no ice, the sea cocks will not freeze, regardless of air temperatures down to -10.
A couple of weeks ago we had a week with daytime temperatures around -2 and it fell to about -6 during the nights, but the insíde temperature in the engine room never went below +5.

Tests have been made in Sweden with different types of sea cocks.
A valve left open will normally not suffer from freezing, it allows the ice to expand in two directions.
A shut gate valve will normally not suffer either.
A shut ball valve will in most cases crack, the trapped water inside the ball freezes, it can not expand and will crack the ball, and sometimes even the housing.

In Sweden, where we have to expect long periods with temperatures down to -20 we normally do one of the following.

Some boat owners just leave their valves open. But personally I don´t like it.

Some rely on shore power with a small radiators, or even 60 W lamps close to the sea cocks. A lamp is enough even with very low temperatures. But then there is a risk if a circuit breaker blows. Personally I don´t rely on shore power.

I use to fill the piping and valve ball with anti-freeze and keep it shut.

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[tcm]

if you are concerned, you could simply lag it with old towels or whatever.

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[vyv_cox]

When I first came to live in Holland in 1996, the weather in January was exceptionally cold. Temperatures never rose above -10C for the whole month and the ice in all the inland marinas was at least 20 cm thick and in the majority more than 30 cm. Very many boats remained in the water (ice) throughout. I asked the harbourmaster at Hellevoetsluis whether any damage had been suffered and he was unaware of a single instance. No doubt several of these boats had received no preparation for such a hard winter but do not seem to have suffered as a result.

In UK the likelihood of such a hard winter must be remote. I don't think I would be worrying. My boat is in the water in Holland, and has been for all of the past seven years except one. Like you, I drain the obvious risk items but leave the rest alone.

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[ianwright]

Less than perfect draining cost me an inlet pump body on my Baby Blake, VERY expensive.
Since then I'm more careful and I use a Paracine Greenhouse fan heater set to anti frost level. Cost about £30 from a garden center and cheap to run.

IanW

<hr width=100% size=1>Vertue 203, Patience

 

[HeadMistress]

Just draining the toilet and fresh water system isn't enough...I suggest you do the following to winterize your plumbing:

FRESH WATER SYSTEM

1. Drain the water tanks completely (just turn on all the faucets).

2. Drain water heater. Most have a drain petcock; follow manufacturer’s instructions to find it and use it. Remove both the inlet and outlet hoses, and if necessary use a shop vac to be sure of gettting all the water out of it.

3.Connect water heater inlet and outlet hoses together. Bypass kits for this purpose are available from boat stores and RV supply stores.

4. Add non-toxic marine/RV antifreeze and pump that through the system until all outlets--hot and cold in the galley, head, shower, and any deck wash--run only antifreeze. Leave all the faucets open to make sure there is no pressure in the system.


SANITATION SYSTEM

1. Pump holding tank out, then rinse thoroughly by completely filling with fresh water and 1 gallon of white vinegar twice.

2. Close toilet intake through-hull, disconnect inlet hose and stick it in a gallon of non-toxic marine/rv antifreeze. Pump the whole gallon through the system into the holding tank. Do not reconnect head intake hose to the through-hull.

3. Pump the head 50 times to get as much fluid out of the system as possible.

4. If the boat is to remain in the water, use a sponge to remove any water left in the thru-hull. If the boat is to be stored on the hard, after the boat comes out open all the sea cocks to drain any trapped water.

SUMPS

Clean and flush with plenty of fresh water. Then add non-toxic antifreeze down all drains that go into the sump. Run the sump pump until you see antifreeze coming out.

If the water never freezes, this may be overkill for a boat stored in the water...but I've learned that it's very hard to go too far wrong erring on the side of caution.

Use ONLY non-toxic marine/rv antifreeze...never automotive antifreeze...in fresh water or sanitation systems.


<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987