PNW winterizing

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Porchhound

Veteran Member
Joined
Jan 6, 2022
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80
Vessel Make
1981 CHB 34
Silverton 34 with twin gas engines. She sits in Port Orchard, Wa on the water. I use a pancake style dehumidifier in the engine room. P.O. didn't go through draining water tanks or hot water heater (both in engine compartment). This seems a little thin in regards to protection to me, but I go the whole nine yards when I winterize my RV which obviously sits on land. He did put a space heater in the salon. I am filling both fuel tanks adding sea foam (1oz/gal). Do I need the antifreeze for my water system?

What do you PNW boat owners do?
 
No anti-freeze. Full water and fuel tanks. Block off engine room vents with 4" foam insulation pipes. Open all water valves, and detach cockpit shower spray head. Leave fridge/freezer and cabinet doors open. Pull mattresses a few inches away from hull sides. Cover windshields and pull down window shades. Dehumidifier sitting and draining in galley sink. Two Caframo True North heaters on low settings, one in the main berth, one in the galley area. Turn off all power except bilge pumps and 110V to outlets and battery charging. Has worked for my NT37 for six winters so far.
 
In Oriental, NC which has a tougher climate than yours, with my boat in the water I put a small heater in the bilge set on about 40 F and a Caframo heater in the main salon with the head compartment doors open. That kept it fine.

But when I pulled it out on the hard to sell it later, I definitely antifreezed the plumbing. Don't fill the hot water tank with antifreeze. Drain and bypass it.

David
 
PNW covers a large area, but the Salish sea covers Puget sound. The sea temp is around 50*F. As long as the boat sits in the water it is heated by 50* water. Why the concern for freezing?
 
We cruise all year in the PNW and don’t winterize our boat at all. But we do have at least one sustained cold snap each year so I leave the diesel furnace thermostat on low all winter on my NT 37 as insurance against freezing and to keep back the damp. The amount of fuel it uses over a season is negligible. I don’t like to count on space heaters due to the risk of power outages when you need them most, and dehumidifiers don’t have a place to drain in the sleeping cabins where they are needed most. I do throw a fresh damp rid tub in each of the bilge compartments to help keep things dry down there and put a hanging bag with a dessicating agent in each of the lockers. Lastly, I put a pancake heater under the engine oil pan to make cold starts easier. Keeps the boat fresh as a daisy and cozy as home.
 
Silverton 34 with twin gas engines. She sits in Port Orchard, Wa on the water. I use a pancake style dehumidifier in the engine room. P.O. didn't go through draining water tanks or hot water heater (both in engine compartment). This seems a little thin in regards to protection to me, but I go the whole nine yards when I winterize my RV which obviously sits on land. He did put a space heater in the salon. I am filling both fuel tanks adding sea foam (1oz/gal). Do I need the antifreeze for my water system?



What do you PNW boat owners do?


Only a short few miles North of you, in SW BC.
Even in winters that are cold enough to have ice around my boat in its shelter in Vancouver BC, this works:
plugged in
water heater left on, heats the ER
heater in the aft cabin on lowest setting
tiny heater in fwd cabin (little heat, but moves the air)
charger left on, adds heat in the ER
29th winter coming, nothing else planned.
 
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The Bellingham area gets an arctic NE wind from BC that most other WA locations don't get, so I add a few steps. Blow out potable and washdown water lines with compressed air. Flush potable AF down the toilets. Hot water tank drained. Block off engine room vents. Three Caframo warm air circulators throughout the living spaces. Compressor-type dehumidifier draining into the galley sink. Engine block heaters on timers that keep the ER 20 degrees above ambient, which I turn on in cold weather. All canvas removed except window covers.
 
We cruise all year in the PNW and don’t winterize our boat at all. But we do have at least one sustained cold snap each year so I leave the diesel furnace thermostat on low all winter on my NT 37 as insurance against freezing and to keep back the damp. The amount of fuel it uses over a season is negligible.

One of the reasons I got rid of the Espar D7L was that it wouldn't come on when the ambient temp fell too low, so as a safe backup for freezing weather it wasn't useful. Seems it needed the fuel to be warm first.
 

Last December in La Conner. Got down to 10F briefly that morning.

Had 2 small electric heaters going, maybe 2000 watts. All interior cabinet doors open. Fired up the diesel stove and the cabin went up to 74F.

Flybridge drains froze solid but no damage.

Blow down water systems, make sure all deck drains are clear of debris. Some safe electric heaters with good connections all around.
 
I tried the electric heaters and crystal drip bucket gadgets years ago. My present boat had both on board when I purchased, plus fans and extension cords to run them. I got rid of all of them, fortunately without spilling the drip bucket thing which will make a huge mess (read The Cat in the Hat to get the basic idea). I was able to sell the (3) heaters on Ebay, so their popularity continues despite being unnecessary in the PNW. In fact, they tend to heat the air above the dew point such that when the air finally contacts a cold surface it can form condensation and mold.

Actually, mold/mildew doesn't need dripping condensation, only a high enough humidity at a certain temperature. The higher the heat (and we're only talking >60F), the less humidity needed. And the higher the heat, the more likely you will have high humidity (condensation) on colder surfaces, like under seat cushions and mattresses. Hence you will likely need a way to lower humidity if a heat source is used. One way to minimize cold spots is to open lockers and raise cushions. That is also effective (maybe more effective) if heat is not used.

A simpler and more effective solution is straight ventilation. Lots of it. Unfortunately, many boats aren't designed for a lot of ventilation in the rain, and in the PNW this is important. If you have covered moorage, most of the problem is solved. If not, you may need to provide additional rain coverage for your various vents. Window screens might be required if vermin is present (ask the marina dock help, not the main office). Probably a bigger consideration is break-ins. So proper ventilation in the PNW does take some effort. But I have found that ventilation is more effective (both cost and mildew) than gadgets. There are no fuses to trip, rendering your anti-mildew system inoperable. Plus, ventilation has never caused a marina fire.
 
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My boat winters in Port Orchard.

Granted, in a boathouse, but that has little to do with the ambient air temp.

Always fill the fuel tanks to the top (diesel). Gas is a different animal as it rots when the corn syrup separates - assumes ethanol.

I empty water tanks & water lines to all locations simply by running the water pump until it is dry.

I usually drain out the engine raw water side by pulling the plug in the strainer - this especially needed as I utilize a fresh water flush at season end.

One 90w bulb is on in the engine compartment when below 40 degrees.

As Marco stated, lots of ventilation throughout the boat with a small fan runing 24/7. open lockers and strategic ports to promote good circulation.


These methods have worked flawlessly since 2002.

Good luck
 
I keep my boat in Olympia and I have had gas and diesel over the years. Because of the water temp I no longer do anything except run fans and several of the small air dryers as made by Davis and/or Cafrano. My tri cabin pilot house lay out is a bit chopped up so I need to use more of each than I otherwise would.
 
Only problem I had last winter was the dribble from the dehumidifier into the sink froze up at the thru hull for the sink. Ice berg hanging on exterior, beat that back with a boat hook.
 
Many NW boaters (BC and Wash) boat year round and therefore, do very little to "winterize", and few seem to have (big) problems.
I did not use the boat during the winter, so in the interest of an abundance of caution, I did winterize in the following fashion:
-installed an oil pan heater (150 W) on the main engine. This kept the ER and the engine warm, dry, and rust free.
- all floor hatches, cabin doors, cupboards, etc. were left open.
-cushions and mattresses were raised up and pulled back from the hull.
-ER vents were blocked with foam insulation.
-No exterior vents, windows were open. Boat closed.
-Engine and Gen Set were freshwater flushed and left that way.
-Drained water heater, water tank, and FW system.
-FW antifreeze in exterior deck (saltwater) washdown system, both bow and stern.

-Dehumidifier in galley sink draining overboard
-Dehumidifier in head draining into shower sump checked regularly.

-Small electric heater in both galley and forward (master) cabin set on low (less than 50 F)
-fuel tanks full
This worked well for me. No smells, no mould, dry, slightly warm boat, with warm engine making for an easy start with little "extra" wear on cold start after sitting all winter (good oil flow).
Probably a bit of overkill, but getting rid of mould and smells can be very difficult. Best to prevent!
 
PNW covers a large area, but the Salish sea covers Puget sound. The sea temp is around 50*F. As long as the boat sits in the water it is heated by 50* water. Why the concern for freezing?

Cuz, it can get damn cold here


I had Wifi temp sensors set up last Winter in Semiahmoo WA (Blaine) in my OA 42. One space heater on low in Master, an oil radiator heater in Salon, and a dehumidifier in the sink. I did nothing in the engine room, relying on the 52 degree water. I was pretty smug watching my boat from home until December 27, when we got down to 8 F. Maybe 20 kt Northeaster. I watched my ER drop to 28 F. Got by with just a destroyed water pump.

This year I’ll stuff insulation into the ER vents. I like the idea of utilizing the hot water heater as well

Cheers
 
Cuz, it can get damn cold here


I had Wifi temp sensors set up last Winter in Semiahmoo WA (Blaine) in my OA 42. One space heater on low in Master, an oil radiator heater in Salon, and a dehumidifier in the sink. I did nothing in the engine room, relying on the 52 degree water. I was pretty smug watching my boat from home until December 27, when we got down to 8 F. Maybe 20 kt Northeaster. I watched my ER drop to 28 F. Got by with just a destroyed water pump.

This year I’ll stuff insulation into the ER vents. I like the idea of utilizing the hot water heater as well

Cheers

What happened to your water pump? Semiahmoo is salt water, so your pump shouldn't have been icy at 28° F.

If you leave your HW tank "on" it will radiate enough heat to keep your engine above freezing. Also if your charger is in the ER and "on" it adds quite a bit too.
 
@mpstan I have temp sensors but none in the ER. I do not remember freezing temps on boat and wonder if your sensor in ER was wind chill reading. Yes I have thought of covering the ER air intakes.
 
What happened to your water pump? Semiahmoo is salt water, so your pump shouldn't have been icy at 28° F.

If you leave your HW tank "on" it will radiate enough heat to keep your engine above freezing. Also if your charger is in the ER and "on" it adds quite a bit too.

My salt water pump was fine. fresh water wasn’t.

Not sure about wind chill— my device was near bilge, don’t think there was much air movement. 28 is 28; fresh water will break things….

i-j5rdJ9j
 
Do I need the antifreeze for my water system?

What do you PNW boat owners do?

We're not in your area, but you can probably mostly winterize your freshwater system with an air compressor.

Blow out all the water from all the lines -- several times back and forth on each leg -- and then disconnect the pump (strainer, accumulator, if you have that) on both sides and then just bump a 1/2 cup of AF through it.

Our water heater was OK with just emptying (as much as possible). Didn't have to be empty (per manufacturer), and we didn't have to put AF in it.

-Chris
 
My salt water pump was fine. fresh water wasn’t.

Not sure about wind chill— my device was near bilge, don’t think there was much air movement. 28 is 28; fresh water will break things….

i-j5rdJ9j

Ahh.
My domestic water pump is within 12" of the hot water tank, so I have never had low temps near it. Maybe yours could move?
 
In 45 years in the Salish Sea, Anacortes and Olympia, I've never had a line freeze. A couple of West heaters at their lowest setting pointed at higher-risk plumbing have worked.

The biggest problem in this region during the winter is mildew. A good dehumidifier draining into the galley sink and good air circulation into all corners of the boat is critical.

One thing to watch out for is the electrical system of your marina. With every heater in the marina coming on during a cold snap, many marinas don't have adequate service. For insurance, a cheap weather station connected to the internet can let you monitor the temperature on the boat and give you a warning that the power is off.
 
No anti-freeze. Full water and fuel tanks. Block off engine room vents with 4" foam insulation pipes. Open all water valves, and detach cockpit shower spray head. Leave fridge/freezer and cabinet doors open. Pull mattresses a few inches away from hull sides. Cover windshields and pull down window shades. Dehumidifier sitting and draining in galley sink. Two Caframo True North heaters on low settings, one in the main berth, one in the galley area. Turn off all power except bilge pumps and 110V to outlets and battery charging. Has worked for my NT37 for six winters so far.

??That is exactly the protocol I have followed for the past 41 years on 2 sailboats and my new to me in 2015 - tv2007 Helmsman 38 (Mariner Seville Pilot House 37). The only time I ever had a problem was the year I neglected to drain water from cockpit shower hose and had to replace shower head. This protocol only works for boats kept in the water. ⛵⛵????
 
What happened to your water pump? Semiahmoo is salt water, so your pump shouldn't have been icy at 28° F.

If you leave your HW tank "on" it will radiate enough heat to keep your engine above freezing. Also if your charger is in the ER and "on" it adds quite a bit too.

Yup, I forgot to mention hot water tank. I did have one freeze on my first sailboat. The ER vent hose terminated right at the hot water tank. If we have a severe "North Easter" forecast, I will leave hot water heater on. And I do leave my Victron 3500 watt inverter charger always on in the charge mode . I don't leave hot water heater on rest of time because it is my understanding that they commonly cause increased electrolysis .
 
In 45 years in the Salish Sea, Anacortes and Olympia, I've never had a line freeze. A couple of West heaters at their lowest setting pointed at higher-risk plumbing have worked.

The biggest problem in this region during the winter is mildew. A good dehumidifier draining into the galley sink and good air circulation into all corners of the boat is critical.

One thing to watch out for is the electrical system of your marina. With every heater in the marina coming on during a cold snap, many marinas don't have adequate service. For insurance, a cheap weather station connected to the internet can let you monitor the temperature on the boat and give you a warning that the power is off.[/QUOTE



ye may be simply lucky. I live in Gibsons and we get COLD blasts down Howe Sound. Same can happen from Indian Arm, a branch of Burrard Inlet and down the Fraser River valley.

If you have inlets aimed at you or nearby be a little more cautious since they are often the sources of the very cold air that hits many areas.

I may have gone overboard but for many years travelled south in our RV so the boat had to be prepared for a winter alone. I had a friend check it but I did not want him to need to do more than minor stuff.

I drained the water tanks, the hot water tank, the supply hoses for the drinking water system. No pink AF though.

I set up a 1,000W heater in the engine compartment that was controlled by a 3,000W thermostat for baseboard heaters laid in the saloon above. Hatch left open. THermostat set for about 4-5oC.

I also leave one 75W heater under the V berth platform and in the lazarette for a small amount of heat.

I use about 20 small muffin or computer type fans mounted on small boards so they force circulation all around the saloon, V berth, eng compartment,
head, lazarette THey only draw about 10Watts each so even the 20 use about 2 amps. THis way I can aim them to ventilate specific areas that proved to be troublesome.

THe cushions, all of them, are laid down flat with 1x2 sticks, each cling wrap wrapped and ends taped, between each so they get some air movement between. THey are pulled away from the walls.

The V berth cushions are raised on old planters, CLEANED, so there is air space.

Almost forgot the two small dehumidifers left on a timer so they did not run 24 hr a day. Usually about 4-5 hrs. One draining to the galley sink, one to the head sink. I modified the collection tank with a small piece of tubing long enough to reach. Each hole was pilot drilled and then enlarged running the bit backwards so to not grab and break the tank. Checked the tube fit each time untill I could just force it into the hole.

The engine coolant is AF and checked.

The raw water circuit is pink AF treated for protection.

All the pumps, FW, bilge are pink RV AF treated.

The toilet and the holding tank and its pump is also pink AF treated.

Batteries were fully charged, voltage noted the day before we left , charger disconnected and then the voltage checked when we returned. THe voltage loss was minimal, about 0.3 V , well within its full charge range.

Of course since I became a home body, no more travel, I can get down to the boat almost any time I wish and I do so, so nothing is likely to go amiss for long. But I still do it all.

Pick out what you wish. If you are able and willing to visit often you likely can get away with less preparation but just monitor the boat often.
 
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I keep my boat in Liberty Bay near Poulsbo. Water Temp has drop to the low 40 degree range on several cold spells. I do the dehumidifier draining into the sink, 130 pancake heaters in the heads and engine room. I also drain the fresh water spigots that are locate in the bow and stern (outside of cabin) using isolation valves and keep the remainder of the system operational. The cabin has been in the low 40's with outside temps in the low 20's with the small heaters. When the cold spells occur I add a 500 watt oil filled heater in the main cabin. I also keep the hot water tank on which is in the engine room.
 
I’m in Gig Harbor. I’ve seen the harbor freeze over out to the middle of the harbor in the winter. While I like the resistant fan heaters (Camfro and others) I don’t like them running unattended. They are also specifically prohibited for use at the dock in an unattended boat due to fire risk.

I have used the low wattage Air Dry circulators. they provide a tiny bit of heat and circulate the air well. I also use dehumidifiers that drain into the galley sink and a small fan in the forward cabin.

Finally, I have a oil pan heater on the boat that I leave on three seasons of the year. It eliminates any moisture in the ER and warms the engine enough that the boat doesn’t ever drop below freezing. The combination of the 4.5’ draft going deep enough in the water, and then the oil pan heater is enough to keep the boat dry and unfrozen.
 

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