Winterization - Antifreeze

[jlombardo]

With October quickly approaching, I am starting to gather all the necessary items to winterize my boat, which brings me to my question. I have had several conversations about antifreeze with several other boat owners on our dock. Last year I purchased three cases of the cheaper -50 degrees gallons from Tractor Supply at $2.50 a gallon. Now I am being told that I should not use that for my motors. That the $18 a gallon stuff has anti corrosive agents in it. Is this true? Is it worth the extra cost? Is there something that can be added to the cheaper stuff that would provide the same or better protection?

Any information would be greatly appreciated.

John

 

[DavidM]

Hmmm, three cases? How many gallons is that? It only takes two gallons to winterize my MH.

Also I think you are confusing engine antifreeze with the RVs potable water system antifreeze. The -50 F stuff is what you should use in your RV.

 

[C lectric]

I use Valvoline coolant/antifreeze with some additives needed.
This stuff is formulated to protect your engine all year round as long as it is maintained to an adequate freezing temperature level.. I change it every 2 years.
Other good mfgrs. of coolant will have similar A/F.


I also use the cheap stuff to FLUSH the raw water side of things but never in the engine cooling system itself.
Going to cheap can have long term effects that you may not like.
My engine is pushing 40 yrs, and 7,000+ hours and has gotten the same treatment every 2 years.
And you should not have to change every year if you use a decent A/F.
JMO

 

[TJM]

I think you should clarify what you are trying to do. I am assuming that you have a boat with a heat exchanger inside, a closed loop cooling system? I am assuming you are winterizing the raw water side that has sea water coming into the boat, thru the heat exchangers (engine, oil and tranny coolers) and then back out to the ocean?
Will the boat be out of the water to winterize? Where are you located? I say this because the technique and your comfort zone might be a little different in the North as it is in the south with a mild potential for a hard freeze. There are several different types of AF on the market. The RV stuff (for fresh water systems) is environmentally friendly (propylene glycol), while the other is ethylene glycol. EG is toxic to water ways. Remember whatever product you might use might get discharged into the water in the spring.
Enjoy all of the responses. This will be a very active thread as there are MANY opinions on this.

 

[jlombardo]

These questions are in reference to winterizing the raw water side of my engines. Marine Power 5.7 liter (GM 350ci). They have a split cooling system, so the motor is cooled by normal car antifreeze through a heat exchanger, and the exhaust is cooled by raw water. I also use the same -50 antifreeze to winterize all water systems including sinks, shower, toilet, washdown, and air conditioners. I assume that the antifreeze that I am using is the environmentally friendly type that you mention. My boat is out of the water when I winterize and open the boat prior to launching so no environmental concerns either way.

John

 

[jlombardo]

Hmmm, three cases? How many gallons is that? It only takes two gallons to winterize my MH.

Also I think you are confusing engine antifreeze with the RVs potable water system antifreeze. The -50 F stuff is what you should use in your RV.

It takes about 5 gallons of antifreeze to winterize each engine, so I go through 10.

 

[Comodave]

When I used to winterize our boats I used the -200 antifreeze. I used a reflectometer to measure the output antifreeze to make sure that it was protected down to -20 degrees. You can’t test the -50 or -60 degree antifreeze. People say they put in antifreeze until they see color coming out but when I would test at first color it would test about 20 degrees not -20. It takes quite a while to get the antifreeze down to -20. I would usually use in excess of 30 gallons to winterize everything on the boat, engines, water system, bilge pumps, heads, wash down pump and miscellaneous things. It was worth it to ensure that everything was protected properly because I didn’t want things to freeze and burst.

 

[Stabi]

from my experience, (over 50 years) of winterizing and being on the hard, in temps as low as -50F, RV antifreeze in your raw water cooling system works fine. At $2.50 per gallon, that is a deal. A while back I posted this from my experiences. This has worked for me with with never an Oh Crap.

Having stored boats for many years on the hard in a place that gets to -50F on a regular basis, my number 1 words of wisdom is to make a complete winterizing list that you refer to every year when winterizing, to make sure that you do not forget anything. Check off every item when completed, then, when it is the middle of winter and the thought of "did I winterize X", a quick look at your list with a check mark will alleviate your fears.

Start with identifying EVERY place where water HAS been. Engine, Sea water lines, Fresh water lines, Bilge etc.

If the engine and gen set are fresh water cooled, check the antifreeze freeze point.

Flush the engine and Genset with fresh water,
Drain everything, Does the boat have a lift muffler, if so, does it have a bottom drain.
Use Polypropylene Glycol (RV Antifreeze) -100 if possible. (-50,will slush at +12F , but will have burst protection to -50F. -50 is most likely a 40/60 diluted mix with water, while a -100 would be a 60/40 mix).
Run the engine and pour the RV antifreeze into the sea strainer (with the thru hull closed and the water removed) or install a bronze (Groco) 3-way valve. Record how many gallons of Antifreeze it takes before it runs out of the exhaust port, so that you will know quantity for next year. ( If the lift muffler has a drain, and/or remaining antifreeze in the sea strainer, this "used antifreeze" can be then be used for the black water system.)

Repeat for Gen Set.

Drain the fresh water tank. Again a 3-way valve will make it easier if you plan on doing this in following years.

Drain the water heater and install a water heater bypass from the cold to hot lines. ( 3-way valves)

Drain all in-line filters.

Install a port ( 3-way valve) just aft of the fresh water pump and used compressed air, adjusted to no more than 40 PSI, to blow all lines. Start with the spigot/faucet that is the farthest away. Fresh water bow wash down maybe, and repeat for every faucet (both hot and cold) heading back to the pump, Do not forget the toilet if it is a fresh water flush. Drain all inline filters again. List every faucet outlet, filter etc. on your list for check off.

Make sure that the line from the tank to the pump is totally drained, filters etc. Make sure that the pump is drained or add a port upstream of the pump and run antifreeze through the pump.

Dishwasher, Washing Machine, Ice maker etc.
Do not forget the windshield washer if it is plumbed into the fresh water system.

Repeat for Sea water pump, do not forget toilet if sea water flush.

If you feel that you blew the lines well enough, OK. OR, repeat the blow out procedure using a little RV Antifreeze to make sure. I made a canister that installs between the compressor air hose and the inlet at the water line, that I can add some antifreeze into and repeat blowing all of the blow previously blown outlets.

Winterize water maker and pumps.

Make sure all sea water strainers are drained and remove water from bilge.

With the "used" antifreeze from the engine, pour some into toilet, both to tank and overboard. Do not forget macerator.
Add a little "used" into all sea strainers and bilge. If any sinks have a trap, pour in "used". Bath drains and pump out sump etc.

Blow all deck drains in case there is a water trap.

Open all thru hulls.

Keep the current year checked off list on board for reference later.

In the spring, use list to commission.

Hope this helps.

 

[jlombardo]

from my experience, (over 50 years) of winterizing and being on the hard, in temps as low as -50F, RV antifreeze in your raw water cooling system works fine. At $2.50 per gallon, that is a deal. A while back I posted this from my experiences. This has worked for me with with never an Oh Crap.

Great information! Thanks much! John

 

[Takeitesea]

I have a Cummins 220 hp engine. I use the cheap pink stuff in the water system. West Marine has -50 pink with additives. It is a little more expensive, about $6 a gallon. I have done this for 13 years and never had a problem. I live in NY.
Hope this helps.