Will water system freeze on boat in PNW water?

D

Doryman

New member
That is the question. I have heard varying opinions on this, some saying that the seawater acts as insulation from the cold air. Obviously it would not work MA or NY but how about here?

I have done it (left the boat in the water for the winter) but I can't remember if I winterized the water system. So what is the wisdom of the collective?

Warren
 
Well, I think you probably did the experiment again a couple of weeks ago when we had temps around 15 degrees and it didn't get about 25 for a few days. Since my TomCat is on a trailer in Everett, I did drain and winterize the system (hopefully correctly/well enough). That was almost (but not quite) as cold as it ever gets around here. Certainly you would be fine with nights that have average low temps but when one of those record lows hits, I think you're rolling the dice. Parts of the water system (like the valves at the sink) are well above the water line of the boat and are hence far away from the warmer water in which you are moored. Fiberglass doesn't insulate the inside of the boat too well nor does is conduct heat very well.

If I were you, and if I didn't want to winterize the water system, I'd leave the boat connected to shore power at your mooring and I'd leave a small heater inside and on during the colder days. Standard space heaters may not have a low enough temperature setting but I know West Marine sells one that can be set to kick on at temps below 40F.
 
I have always been told the same, that the warmer seawater will provide some thermal protection by way of conduction with the nearby air. I have only ever relied on this for those 'staying in a bit late in the season' but never for a full winter. I would rather be safe than sorry with the Tomcat.

Besides - once you have it down to a science it's really not too big a job. Buy 6 gallons of rv/marine antifreeze:

1.) Run your faucet until the water is out, run the shower (both hot and cold knobs for sink and shower), drain the hot water tank, and flush the toilet.

2.) Install the bypass on your hot water heater (heat gun is your friend).

3.) Add at least 4 gallons of antifreeze to your fresh water tank and run the sink and shower knobs until pink comes out. (Please don't let the antifreeze dump into the ocean :) tie up a bucket in front of the sink drain and shower drain to capture if doing the procedure in the water). Flush your toilet a few times to make sure you see pink in the bowl. This procedure will make sure the water is flushed from the hoses.

4.) As a final check - look under your sink to make sure ALL hoses are pink. This is how you know for sure you got all of them. Also make sure your shower sump has pink fluid.

Voila...

I also make a point to cycle some antifreeze through my fish boxes and bilge pumps. Once again bucket tied to side to capture the bad stuff. Even "non-toxic antifreeze" is toxic to fish and you don't want to eat it.


Now in terms of the engines you have two choices - full down to be sure the lower unit will not have residual water that may not fully drain and freeze (but dealing with growth and corrosion) or tilt them up and hope all the fluid drains out and does not freeze (avoiding corrosion and growth). I always take mine out for the winter so I've never had to make the decision. I see boats in Boston Harbor with the engines up for the winter and I see them with the engines kept down. An ice blown lower unit would really sting.

The good news about growth...it will be MUCH less pronounced in the cold winter vs. summer.

--Matt
 
If you keep it in the water here, it seems the small heater does the trick if the seawater looses its edge. We are into our second winter and no damage to speak of. We keep the system fully watered with no antifreeze but we do leave a small heater in the boat set to about 38 degrees. We also prop open all of the cabinets doors hiding plumbing. We have thermometers inside and outside the boat and it is easy to see the "warming effect" of seawater between those two sensors on a cold day. I have been out to the boat and caught the heater running but only on the coldest days/nights and our power bill demonstrates that the heater does run but not very often only using about 3-4 dollars per month on the meter.
 
One suggestion regarding add the pink RV antifreeze to the lines: disconnect the hose before the pump and put the hose in the RV antifreeze bottle; draw the antifreeze out with the pump. This way, you will not have the pink stuff in your fresh water tank and you will only use about a gallon of antifreeze. When time comes to put water in the fresh water tank again, you won't have the foamy pink stuff in your lines for the next 3 tank fills. :wink: Be sure to put some pink stuff in your shower box until you see that pump out.

Alternatively, you can use a small compressor to blow out the lines; then there will be no pink stuff to deal with. We've done it both ways with boats and RVs for a couple decades.

With your weather in the PNW, there will likely be times you want to use the boat even in winter, right? (You guys are tough.) The less pink stuff you have to put in, the less expense and easier it is to de-winterize.

Stay warm.

Best wishes,
Jim
(still in the frozen northland, where the blizzard has passed and it was only -8 last night :disgust )
 
Aurelia":1u8lggqz said:
If you keep it in the water here, it seems the small heater does the trick if the seawater looses its edge. We are into our second winter and no damage to speak of. We keep the system fully watered with no antifreeze but we do leave a small heater in the boat set to about 38 degrees. We also prop open all of the cabinets doors hiding plumbing. We have thermometers inside and outside the boat and it is easy to see the "warming effect" of seawater between those two sensors on a cold day. I have been out to the boat and caught the heater running but only on the coldest days/nights and our power bill demonstrates that the heater does run but not very often only using about 3-4 dollars per month on the meter.
Click to expand...

That sounds like the way to go. If I can avoid using RV antifreeze that would be best because I would like all the systems to be operational for winter outings.

As I think back to the winter that I left the boat in the water, I am fairly certain that I did not winterize, and had no problems.

Do any of you Tom Cat owners open up the sponsons to warm air? If so, how? There is the access to the washdown through-hull below the hanging locker and there are the access panels underneath the berth mattress.

Thanks, everyone.

Warren
 
I posted on the other winter threads but my question is this. Will freezing somehow ruin/toast or other wise trash the water pump? I blew out the entire system after the pump, ran pink AF through the bilge pump, shower box pump and even the mascerator and drained the heater, but I did not run some through the water pump. I know... :roll: Now it will not pump (nothing; no sound, no pressure...nothing) and I confirmed it has 12v.
 
localboy":3rybu8zx said:
I posted on the other winter threads but my question is this. Will freezing somehow ruin/toast or other wise trash the water pump?
Click to expand...

Yes it will/can. Don't ask me how I know! :twisted:

Warren
 
I have not winterized larger boats that I kept in the water.

Two years ago when we had a bad cold snap, I was a bit concerned about the risers / manifolds on the boat, but wasn't much I could do about it. The water heater for the potable water system was in the engine room, and I kept it on (with water in the potable water system) figuring that the heated water would help keep the engine room above freezing.

I had no problems when the weather warmed up.

The only freeze issue I have had was a potable water filter unit freezing on a boat that was stored out of the water.
 
After reading some discussion several posts above, I thought I'd simply point out that a small electric heater in the cabin will not protect your bilge pump or any other water appliance that is outside the cabin area.

Joe. :teeth :thup
 
My rear bilge under the cockpit works fine and I have never done anything to winterize it. I do try to keep the area relatively dry so I suppose if there is no water sitting in the bilge there should be none in the pump to freeze/crack it. It got lots of use just after the last cold snap during my holding tank removal project and it worked great removing fresh rinse water. It does sit about 1.5 inches from the salt water so that may help moderate conditions a bit.
 
Something to keep in mind is that while the boat may be in a body of saltwater, the water at the surface is not necessarily very salty. In my marina in Bellingham, the surface will frequently freeze during a cold snap due to fresh water runoff that floats on the surface. That will be the same water that is in the raw water part of the boats systems. During the recent cold weather "salt" water did freeze inside my bilge and raw water pickups. I had disconnected all hoses and shut the seacocks, so no problem. But yes, precautions should still be taken if extreme cold is expected in the PNW.
 
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