how to keep bilge from freezing?

[sdowney717]

Our boat sits in the water here near LAFB in Virginia.
We have had really cold air into the teens which is unusual.

The small amount of salt water in the bilge has frozen and this has frozen in a couple bilge pumps.

After the bilge thaws, I plan to raise the 2 new Rule 3700's I added above the normal bilge water levels so they cant freeze.

So what is a useful idea to prevent ice in the bilge?

Light bulbs? I have done that in past years.

 

[sdowney717]

some icy pics. The boat hook showed the ice to be about 3 inches thick soft ice.

 

[TeddyDiver]

You have shore power? There are self regulating warming cables for waterpipes you could ask from a plummer. Set one in the pilge..

 

[sdowney717]

yes we have shore power.
Electric heat tape, though would it put out enough heat to keep that lake in the bilge liquid?

See when it rains, water gets in the bilge.
And likely a few tiny hull leaks let in some bay water.
The pumps cant pump it all out, so a couple inches can collect before the pump comes on. Would be nice to have a system that pumps it dry.

 

[sdowney717]

http://www.ebay.com/itm/Norpro-559-300-watt-Immersion-Heater-NEW-/180467328155

immersion heater looks interesting. Although it might get too hot.

I do have a heater made to go in an engine oil dipstick. Long and skinny. Might try it.

 

[TeddyDiver]

If you get something too powerfull you're gonna have a lot of humidity and condensation problems elsewhere. Thou a thermostate helps to that.
This http://www.thermon.com/us/products.aspx?prodid=37 is KISS

 

[sdowney717]

The dipstick heater is likely only 100 watts.
I also have a defrost thermostat from a freezer that goes on at 22*F and off at *50F. This could be wired into the circuit.

I wonder if the thermostat is worth using.

 

[TeddyDiver]

Yes it is.. Antifreeze cable has only a few watts per meter/yard.

 

[viking north]

If it were my boat and there was anything over a couple of gallons i'd be very aggressive about getting it out before any damage was done if not already so. I've seen bilge water freeze in wooden boats and push garbard planks off the frames. I've also seen it split fiberglass hulls right down the inside center of the keel. I recommend getting a good heavy heater to work and melt out the ice to the point where you could pump or remove it in chunks. Once you get it out either tarp the hull to prevent more water getting in or pour in enough plumbers antifreeze to limit the freezing of new water to a slush which will not do freeze/expansion damage and which you can simply shovel or pump out after a little heating. I have included a photo I took yesterday of a local boat that was a victim of your very problem. Ice in the bilge is nothing to take lightly. Good Luck.
P.S. when you put your boat away in the fall, on land or in the water pour 5 gal. or so of non toxic plumbers antifreeze(RV antifreeze) into the bilge .

 

[JSL]

1.check with your marina as to what heater type you are allowed to use. Open type electric (element + fan) are banned is some areas due to fire hazard.
2. Make sure your seacocks are closed. Water freezes = hose may expand = rupture . When it thaws, the plug (ice) melts and your boat can sink.
3. The boat should be ventilated. Heat holds moisture, leads to mold. Not the kind of 'culture' you want to greet you in spring

 

[sdowney717]

I have noticed about freezing salt water ice seems to be softer than pure fresh water. I have yet to have anything damaged from ice in the 15 years the boat has been here.
Seeing that much ice in the marina is extremely unusual.

 

[viking north]

The extreme cold temperatures these past two years generated by that Siberian Air trapped by the jet stream and driven further east and south in North America is indeed a new pattern. Hopefully not a sign of things to come but something we should indeed gear up for. Salt water does freeze at a lower temperature but still has the potential to do expansion damage. I think you mentioned it was rain water (fresh) getting into your bilge but regardless bilge water freezing and expanding is not good especially if it locks onto crevices or contours that prevents an upward expansion during the freeze cycle. The old stone masons made use of this cycle to split huge granite stone building blocks. As I said if it were my boat I would get it under control pronto.

 

[AndySGray]

You got shore power so you can get that last bit of water out of a bilge with a wet'n'dry vacuum cleaner...

Now, is there a way to automate that process ?

 

[CDK]

Throw salt in the bilge!
Alternatives are sugar, methanol or ethanol, all far more expensive than ordinary salt.

 

[viking north]

Yup salt will do the trick but be sure it's corrosive action is not destroying more than ice. All the old wooden boat boys used salt to protect their bilges from ice while recognizing that it was shortening the life of the hulls fasteners. "History Bit" it is estimated that more Newfoundland sailing ships sank in the salt run from Spain to Newfoundland than all the other routes they took world wide. Salt was the bane of bilge pump intakes during storm conditions.