The Basics of "In Water" winter storage

Warning: The following is intended as a basic guide only. The boat owner should understand that each boat may have something unique to be contended with.  Hydro Aeration accepts no liability for offering the following.   It is recommended the assistance of a marine mechanic be utilized for at least the first winter season lay-up.
Same basic precautions apply for wet storage and dry storage. Engine must either be drained of water by removing all plugs in engine block, manifolds, water pumps, etc. or flushed with antifreeze.
One method of flushing:
1. Shut off sea cock at engine raw water intake thru hull fitting
2. Disconnect [at thru hull fitting] hose connection between fitting and engine
3. Place end of hose disconnected from thru hull fitting into container of anti-freeze and start engine. Anti-freeze should circulate thru engine and be discharged thru exhaust pipe.
NOTE:  If the exhaust pipe end is submerged or subject to water thru wave action care must be taken to prevent freezing within the exhaust system. One method is to attach a hose to the exhaust pipe and raise the end of the hose slightly above the water surface. When anti-freeze is observed flowing from exhaust shut off engine.
NOTE: If engine is thermostat controlled care must be taken to assure anti-freeze flows thru thermostat. Either remove thermostat prior to winterizing engine or be sure engine has been run and heated enough to assure thermostat remains open during winterizing.
NOTE: any reference to anti-freeze in this section is to antifreeze of the RV [recreational vehicle] type. Any other type may be poisonous.
2. Drain tank. Because each installation may be different it is difficult to cover all types. Objective usually most easily accomplished by disconnecting line FEEDING tank [or that line someplace at a location lower than tank] and disconnecting line from tank to water system. Line from tank to water system is disconnected to break vacuum created by draining tank. Simply opening faucet [hot water] nearest tank will usually suffice.
3. Because some water may remain in tank you may wish to pump some anti-freeze into tank after winterizing water system.
WATER SYSTEM [plumbing ]
System may be drained, flushed with anti-freeze, or blown out with compressed air. If system is drained or blown out water may remain in low spots of lines. Take care to avoid. To flush:
1. Shut off all plumbing fixtures [faucets, etc.] and electrical
supply to water pump.
2. After draining water storage tanks, disconnect pump feed line
from storage tank to pump.
3. Install temporary line to by-pass hot water tank. This line should serve to connect the lines normally leading to and from the hot water tank, thus by-passing the tank.
4. Connect pump to a line leading to container of Recreational Vehicle type anti-freeze.
5. Turn on electrical power to pump.
6. Beginning with faucet nearest pump, open each faucet until anti-freeze flows, then close and move on to next faucet until all faucets have been tapped.
7. Turn off electrical power to pump.
  Now you may wish to pump some anti-freeze into the hot water tank To do so:
1. Disconnect by-pass line [item 3 above] and reconnect water supply INLET line to hot water tank.
2. Cap off line normally running FROM hot water tank to water system. Do not cap the HOT WATER TANK OUTLET air will be displaced by anti-freeze pumped into tank and will be vented here. The object here is to prevent anti-freeze being pumped from the already winterized lines as the pump is pumping into the hot water tank.
3. Turn on electrical power to pump.
4. When sufficient anti-freeze has been pumped into hot water tank turn off the pump.
5. Reconnect all lines as when the system is in use. In the spring simply open all hot water faucets and run water until the water tank is filled and all lines purged. Do the same with the cold water side. LAST, reconnect power supply to hot water tank.
WATER STORAGE TANKS are usually winterized by simply draining and if necessary pouring some RV anti-freeze into the tank via the filler fitting in the deck.
Best suggestion here is to follow manufacturers instructions for winterizing or contact a marine mechanic.
  THRU-HULL FITTINGS, SHAFT LOGS, RUDDER POST LOGS located near or below the water line must be winterized and kept from freezing. Although the water around the boat may not be frozen, the temperature inside the boat may be below freezing. Because a heat source is being induced by bubbling, the chill factor is important. Extreme cold and wind can lower the temperature inside the boat below freezing even in the bilge.
  Any method of heating will work. Hydro Aeration cautions against the use of electric space heaters as a fire hazard. Wrapping fittings with electric heat tape could create electrolysis. Any type of open flame in the bilge is out of the question and not recommended left unattended any place any time.
Light bulbs of 25 to 60 watt, backed with a reflector, placed close to the fitting and shining on it are simple, effective, and efficient. Be sure all electrical connections are secured well out of any water in the bilges.
   Thru hull fittings should be filled with a substance that will not freeze. Oil works well; but extreme care must be taken to prevent oil getting into the water. Whatever substance you use following is one method of filling the fitting.
1. Shut off the sea cock gate valve, or whatever thru-hulls exist at the fitting.
2. Disconnect the hose from the fitting.
3. Secure a hose of proper diameter on the fitting and blow into the hose [lung power is usually sufficient] as you open the sea cock. When you hear "bubbles" from the sea cock shut the sea cock BEFORE YOU RUN OUT OF AIR and you will now have a sea cock void of water.
4. Pour your choice of liquid [if you use oil be careful to avoid a spill into the water] THAT IS LIGHTER THAN WATER AND WON'T FREEZE into the hose you just finished blowing air thru. Pour in just enough to fill the sea cock, usually an inch or so, and allow it to flow down the hose to the sea cock. When you are sure the liquid has flowed to the bottom of the hose, again blow
into the hose as you did in 3 above BUT SHUT THE SEA COCK BEFORE YOU FORCE THE LIQUID COMPLETELY THRU THE SEA COCK. This should fill the sea cock and entrap the liquid. If you hear "bubbles" you over did it. Repeat step 4 again.
5. In the spring open the seacock and catch your liquid in a container before it goes into the bilge, shut the sea cock, reconnect the original hose and open the sea cock.
   For thru hull fittings not perpendicular enough to the water to allow filling with a non freezing liquid follow all the steps except 4. You might want to place a slightly higher watt light in such a location. Take caution not to create too much heat that might deteriorate the hull or become a fire hazard.

BATTERIES should keep the winter if they are in good condition and properly charged at lay-up. It is recommended the batteries be periodically checked for charge or failure during the winter and be replaced or charged as needed. Leaving a constant charger on the battery continually is hard on the battery and a fire hazard. A good battery in a charged condition should not freeze. You don't put your car battery in the basement all winter.

BILGE PUMPS should be operable in case of a leak or to pump out rain water or snow melt. An automatic bilge pump is a must. A simple 110 volt sump pump with a typical marine float switch wired in is highly recommended as a backup to your 112 volt pumping system. Place a light or something at the bilge pump as you did with the thru hull fitting to prevent water turning into ice before the pump can pump it out. Some non-toxic antifreeze should be put into the pump pit as well.

Marine type  air conditioners use water to cool the condenser. A pump with strainer force cooling water thru the coil and discharge over the side. Some air conditioners are heat pumps as well and still use the cooling effect water. It is not recommended to use this as a source for heat during the winter as the unit will cycle and it is during this off cycle that it could freeze up.
Any system requiring water for operation will probably need to be winterized to prevent damage by freezing. If you have a thru hull fitting it serves a purpose: as an intake or an exhaust for something. That something must be winterized. Generally, simply flushing a system properly with anti-freeze should suffice, however, manufacturer's directions should be consulted and followed.
As a final note, it is wise to be aware that "in-water" winter storage is not covered by most insurance companies, and extra coverage for things like storm damage and freeze damage to the hull would have to be purchased in addition to your regular policy.

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