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I was checking out if the ice in the Potomac and my marina had cleared today. Big difference from yesterday. Looks like I might go sailing tomorrow !
As I was leaving the dock, the marina manager was checking out a motorboat that had a slight lean to it and had it's bilge pump on constantly. He offered to show me what the story was in the bilge. I am not that much up on the motor cooling arrangements on boats but it appeared that the valve/strainer that connects below the waterline developed a crack probably from the deep freeze we have experienced the past 2 weeks. The bilge pump seemed to be mostly handling the water but was on constantly. The valve was open and it appeared that water had frozen inside the pipe/hose just inboard of the valve. The manager shut the valve. I am not sure why it was left open in the first place. The crack in the pipe was obviously going to have to be fixed but the big unknown was...what about the engine. I am nost usre if the owner had winterized the motor since he had an engine heater in the compartment.
Anyway, that got me thinking about my seacocks. The seacocks are not flush against the hull. There is perhaps a 1 1/2" pipe/thru hull fitting that connects to the valve. The seacocks are shut and there are deicers in the marina but that little 1 1/2" part of the fitting between the river water and the outer part of the valve could be subject to freezing. Perhaps since it is such a small area, it does not expand in that space..but I am not sure. We have had temps for a period of time in the teens and so a good part of the marina had light ice in it even with the deicers/flow movers. But in crevices, etc there is not water turbulence and so those areas could be subject to freezing. Boat neve rhad a problem with past owner and it was dry when I checked it out yesterday. But...maybe I will install an auto-bilge pump. Still...what about that 1 1/2" fitting below the valve ? I do not think anything can be done about that unless perhaps heat tape was put around the seacock/hull in that area.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by OLarryR</i><br />Still...what about that 1 1/2" fitting below the valve?<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">I'm pretty sure that in temperatures where de-icers are effective, if a small cylinder of ice even formed in the mouth of the tru-hull, it would bulge outward rather than crack a bronze casting that thick.
Picture a small steel soup can of water left in a freezer until frozen solid. True, the can will never be the same. But you'll notice the surface of the ice forms a cone shaped peak because the pressure resistance of the can walls forced the partially frozen ice to 'flow' towards the lower pressure outside the can.
Now if the thru-hull is nylon or badly dezincified, or otherwise weakened bronze, all bets are off, and the insurance better be paid up!
It's possible that the powerboat had a raw-water-to-coolant heat exchanger, and that the engine itself used an antifreeze-based coolant, like a car. It that situation, the raw-water side of the system (strainer and exchanger) is vulnerable when temps go down inside the hull, but the engine should be safe.
Your thru-hulls should be OK below the seacocks as long as there's unfrozen water around them (outside of the hull). Your thru-hulls should be well below the skin of ice that might appear in parts of the marina. The tiny amount of water below the seacock in the thru-hull should stay just about the temperature of the outside water, since water holds much more heat and conducts it better than air. But you should make sure there's some antifreeze in the lines above the seacock, since it's inevitable there will be some water in there, and that <i>will</i> be cooled close to the air temperature.
The seacocks on the '89 are of a composite/plastic type matl.
It is true that the deicers keep whatever ice is in the marina to a relatively thin nature. When the temps were really cold for a few days, my boat had ice close to it on one side, within inches. The other side, the ice was about 1 1/2 feet away. Then a day or so later, I noticed that the marina staff relocated a strong flow mover/deicer closer to my boat and the ice had receded quite a bit with none that close.
The previous owner did not use the holding tank at all but there could very well be water in the drains to the seacocks.
I had also thought about this since I'm leaving my boat in the water over the winter. My marina is using de-icers so I'm not very concerned about the ice around my boat. One concern I thought of is the swing keel hose. Does anyone think it is possible for the water in the keel hose to freeze and expand since the hose is longer than a regular seacock and probably subjected to more of the air temperature? Since it is an open hose on both ends, if freezing is possible hopefully it expand upward like the tin can example that Leon mentioned.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Justin4192</i><br />...Does anyone think it is possible for the water in the keel hose to freeze and expand since the hose is longer than a regular seacock and probably subjected to more of the air temperature? Since it is an open hose on both ends, if freezing is possible hopefully it expand upward like the tin can example that Leon mentioned.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">...Or the repeated freezing and expanding cycles will slowly but surely pry the hose up off the (barbless) to-hull. I think it's more likely to work as I described if it even freezes at all. The heavy wall bronze pipe would force the ice to expand out its ends, and the hose would flex enough to handle the expansion in it without damage. Keep in mind the cable runs through there too. The (relatively) warmer water would 'heat' the cable, which would then conduct above freezing temperature up into the pipe and hose, further reducing the likelihood of a hard plug of ice developing enough pressure to do any real harm. You do have at least two strong hose clamps tightened down on the hose, don't you?
There are two clamps on it, but both the hose and clamps need to be replaced. I'm replacing all the keel hardware in the next couple months when I haul out to get several projects completed.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Leon Sisson</i> <br />The heavy wall bronze pipe would force the ice to expand out its ends, and the hose would flex enough to handle the expansion in it without damage.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> Leon... You Florida guys say stuff like that and then wonder why your houses are full of water when the temperature drops into the teens every 50 years or so. For one thing, if a hose is "reinforced", when water freezes in it, it'll burst--we northern guys all know that from <i>repeated</i> experience. (Forget one over the winter--you'll buy a new one and a new nozzle next spring.) As for bronze, if you're lucky, ice will push itself out--if you're not (a barnacle, perhaps), it'll break like china. Nothing is strong enough to prevent the expansion when water freezes. Don't take chances with ice--it'll disappoint you every time.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.