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Winterizing tip

Sep 25, 2008
380
Catalina 30 MKIII Varuna Boat Club
Hi all,
I finally discovered the leak causing my fresh water system pump to cycle every 20 seconds, when all fixtures are turned off. The search for the leak was exasperating.
Turns out that one of the head faucet feed nylon elbows had a tiny pinhole and a very, very fine stream of water was escaping, causing the pump to recycle. This also resulted in the frustrating discovery of just a little water collecting in my bilge.
Since I bought this boat (it was sitting on the hard for almost 2 years), it appears that poor winterizing by the PO had to be the culprit. Fitting elbows are always the first to suffer from freezing cracks and this one was no exception.
Bottom line; if you want to go nuts trying to find a minute lead....somewhere....in your fresh water system, do not winterize properly.
Make sure you run RV antifreeze through the system until ALL the fixtures run pink.

Happy Sailing..
 
Mar 26, 2011
2,371
Corsair F-24 MK I Deale, MD
Hi all,
I finally discovered the leak causing my fresh water system pump to cycle every 20 seconds, when all fixtures are turned off. The search for the leak was exasperating.
Turns out that one of the head faucet feed nylon elbows had a tiny pinhole and a very, very fine stream of water was escaping, causing the pump to recycle. This also resulted in the frustrating discovery of just a little water collecting in my bilge.
Since I bought this boat (it was sitting on the hard for almost 2 years), it appears that poor winterizing by the PO had to be the culprit. Fitting elbows are always the first to suffer from freezing cracks and this one was no exception.
Bottom line; if you want to go nuts trying to find a minute lead....somewhere....in your fresh water system, do not winterize properly.
Make sure you run RV antifreeze through the system until ALL the fixtures run pink.

Happy Sailing..
Yes, that was exactly my experience with my last boat. The PO swore by just blowing out the lines, and as a result many were either worn from repeated disassembly or stretched-cracked as you described. Steel and rubber can take it, but not plastic.
 
Oct 8, 2013
27
Beneteau 321 1999 Rose Haven, MD
For this year's winterization dance, we bought a small shop vac with an exhaust port (for blowing out through hull fittings before adding antifreeze). I was thinking - has anyone had success vacuuming the fresh water system (after isolating and draining the hot water tank), e.g., from the tank, instead of blowing it out with a compressor? I guess you'd have to bypass the pump. Or, maybe, just put in a pair of shunts at the pump and effectively run the fresh water pump in reverse, pump all the fresh water into the tank, and then vacuum it out? Maybe just pumping several gallons of the pink is a better idea ....
 
Mar 26, 2011
2,371
Corsair F-24 MK I Deale, MD
For this year's winterization dance, we bought a small shop vac with an exhaust port (for blowing out through hull fittings before adding antifreeze). I was thinking - has anyone had success vacuuming the fresh water system (after isolating and draining the hot water tank), e.g., from the tank, instead of blowing it out with a compressor? I guess you'd have to bypass the pump. Or, maybe, just put in a pair of shunts at the pump and effectively run the fresh water pump in reverse, pump all the fresh water into the tank, and then vacuum it out? Maybe just pumping several gallons of the pink is a better idea ....
Running the pump backwards won't help; there are check valves.

The problem (challenge?) with blowing or vacuuming a system is that if you miss any and there is vulnerable equipment in a low spot, it will be damaged. Also, small bits of water trapped in valves, pumps, and constrained areas of certain fittings can cause damage. Glycol tends to ferret these out. Cycle all valves during the process.
 
Jul 12, 2011
785
Catalina 36 Bay City, MI
Just a reminder ... after you haul out and everything is done. Empty the bilge as much as you can and dump a gallon or two of pink stuff down there and run cycle through all the pumps. Between sags in the lines and diaphragm pumps, I must have a gallon of water left between bilge and through-hull, even if the bilge is dry.
 
Mar 16, 2010
5,943
Beneteau 411 Oceanis Annapolis
I was thinking - has anyone had success vacuuming the fresh water system (after isolating and draining the hot water tank), e.g., from the tank, instead of blowing it out with a compressor?
Yes, I use a shop vac (in wet mode) to vac out my tank and plumbing lines prior to pumping in AF. Less dilution with water, less antifreeze. BTW, I never add AF to my potable tanks. Pump and drain the tanks, pull the supply line loose at the plumbing manifold, jam a funnel nipple into the tank lines and nest the wet vac hose into the funnel to draw any remaining water from the tanks and related supply lines. I will often let it vac for 10 minutes. Same thing with the potable system - open all the faucets and vac out water. Pump in PG AF.
 
Jul 8, 2005
414
Beneteau 321 Grosse Pointe Farms, MI
For this year's winterization dance, we bought a small shop vac with an exhaust port (for blowing out through hull fittings before adding antifreeze). I was thinking - has anyone had success vacuuming the fresh water system (after isolating and draining the hot water tank), e.g., from the tank, instead of blowing it out with a compressor? I guess you'd have to bypass the pump. Or, maybe, just put in a pair of shunts at the pump and effectively run the fresh water pump in reverse, pump all the fresh water into the tank, and then vacuum it out? Maybe just pumping several gallons of the pink is a better idea ....
Hi Adam,
We also have a B321. Was looking for posts to get an idea about how to mount a GPS on a B321. Curious if you have done.
On winterizing, I have done myself for 20 years since we owned the boat. For the engine, I just open the sea strainer and run a couple gallons thru the engine when it is up on the cradle. Once the color is coming out the exhaust, we stop. Takes two people to do (one to pour and one to start the engine). For the water system, I have a 3 foot section of hose with a coupling at one end. I remove the water intake from the pump and screw in the 3' section of hose. Stick it in the pink stuff and run the water pump. Pumps pink thru each faucet once you turn them on. Has worked in Michigan for 20 years.
 
Oct 6, 2007
658
Hunter 1982 H30 Cherubini Chicago (Burnham)
Hi Adam,
We also have a B321. Was looking for posts to get an idea about how to mount a GPS on a B321. Curious if you have done.
On winterizing, I have done myself for 20 years since we owned the boat. For the engine, I just open the sea strainer and run a couple gallons thru the engine when it is up on the cradle. Once the color is coming out the exhaust, we stop. Takes two people to do (one to pour and one to start the engine). For the water system, I have a 3 foot section of hose with a coupling at one end. I remove the water intake from the pump and screw in the 3' section of hose. Stick it in the pink stuff and run the water pump. Pumps pink thru each faucet once you turn them on. Has worked in Michigan for 20 years.
You either forgot to mention getting the engine up to temperature first or your engine may be different from others. Mine, a raw water cooled Yanmar 2GM, has a cooling water bypass thermostat. If the engine is not up to temperature yet, the anti-freeze can be by-passing the engine block. If you start running anti-freeze through immediately after a cold start on a cold day, you can see color coming out of the exhaust, but may not actually be winterizing the engine block.

This is why I winterize the engine as soon as we tie up at the haul out dock. After the four or five hour river trip I know the engine is hot and the antifreeze will not by-pass the engine block. I also run a full 2 gallons of antifreeze through even though we start to see color about half or three quarters through the first gallon. Want to make sure it’s pure antifreeze coming out before I stop. Cheap insurance IMO. I drain the sea strainer and all sea cocks after haul out.

Your water system winterization procedure is pretty much the same as mine.
 
Last edited:
Jul 8, 2005
414
Beneteau 321 Grosse Pointe Farms, MI
You either forgot to mention getting the engine up to temperature first or your engine may be different from others. Mine, a raw water cooled Yanmar 2GM, has a cooling water bypass thermostat. If the engine is not up to temperature yet, the anti-freeze can be by-passing the engine block. If you start running anti-freeze through immediately after a cold start on a cold day, you can see color coming out of the exhaust, but may not actually be winterizing the engine block.

This is why I winterize the engine as soon as we tie up at the haul out dock. After the four or five hour river trip I know the engine is hot and the antifreeze will not by-pass the engine block. I also run a full 2 gallons of antifreeze through even though we start to see color about half or three quarters through the first gallon. Want to make sure it’s pure antifreeze coming out before I stop. Cheap insurance IMO. I drain the sea strainer and all sea cocks after haul out.

Your water system winterization procedure is pretty much the same as mine.
Dalliance,
We have a 3GM30. Not sure if we have the cooling water bypass thermostat. I will check.
Probably better for me to do what you mention just to be sure. It is 'safer' anyway than starting up on the cradle. At least I know that only coolant gets into the engine system. I suppose I could shut off the water intake valves.
Thanks for the info.
 
Oct 22, 2014
352
Pearson P303 #221 RockPort Maine
You either forgot to mention getting the engine up to temperature first or your engine may be different from others. Mine, a raw water cooled Yanmar 2GM, has a cooling water bypass thermostat. If the engine is not up to temperature yet, the anti-freeze can be by-passing the engine block. If you start running anti-freeze through immediately after a cold start on a cold day, you can see color coming out of the exhaust, but may not actually be winterizing the engine block.

This is why I winterize the engine as soon as we tie up at the haul out dock. After the four or five hour river trip I know the engine is hot and the antifreeze will not by-pass the engine block. I also run a full 2 gallons of antifreeze through even though we start to see color about half or three quarters through the first gallon. Want to make sure it’s pure antifreeze coming out before I stop. Cheap insurance IMO. I drain the sea strainer and all sea cocks after haul out.

Your water system winterization procedure is pretty much the same as mine.
Please tell me more about this BYPASS THERMOSTAT! I have a 2GMF with a heat exchanger does your 2GM only use just raw water to cool??
 
Oct 22, 2014
352
Pearson P303 #221 RockPort Maine
Dalliance,
We have a 3GM30. Not sure if we have the cooling water bypass thermostat. I will check.
Probably better for me to do what you mention just to be sure. It is 'safer' anyway than starting up on the cradle. At least I know that only coolant gets into the engine system. I suppose I could shut off the water intake valves.
Thanks for the info.
If you have a heat exchanger you do not have a BYPASS thermostat and your engine is not directly raw water cooled. Your antifreeze is cooling the engine and the raw water is cooling the antifreeze via your heat exchanger. Capt. Rob
By the way, I installed a freshwater flusher system as well it can distribute antifreeze throughout your boat from one source, your Water Tank! Im in salt water so at the end of a trip I FLUSH. My engine never sits with salt water in it.
https://forums.sailboatowners.com/index.php?threads/why-install-an-fresh-water-flusher.193174/
 
Last edited:
May 17, 2004
1,863
Beneteau Oceanis 37 LE Havre de Grace
I have a 2GMF with a heat exchanger does your 2GM only use just raw water to cool??
The F in the 2GMF stands for being fresh water cooled. As you said, and fresh water cooled engine will run the raw water through the heat exchanger at all times, since the thermostat only controls the flow of the fresh water. On the nom-F model the thermostat does affect the flow of the raw water.
 
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Oct 6, 2007
658
Hunter 1982 H30 Cherubini Chicago (Burnham)
My 2GM is raw water cooled; no heat exchanger. Here is the Yanmar Service Manual diagram of the 2GM cooling system. If the engine is not to temperature, the flow of raw water though the engine block is shut off and the water by-passes directly to the mixing elbow.
2984A99C-990F-4B1D-A5A8-B5D24CB5FD1E.jpeg
 
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Oct 22, 2014
352
Pearson P303 #221 RockPort Maine
My 2GM is raw water cooled; no heat exchanger. Here is the Yanmar Service Manual diagram of the 2GM cooling system. If the engine is not to temperature, the flow of raw water though the engine block is shut off and the water by-passes directly to the mixing elbow. View attachment 165011
What type of MIXING elbow do you have Dalliance???