When summer turns into fall, most DIY boat owners start exchanging ideas on how each one proceeds with their winterizing process. This is definitely one of the great benefits and pleasures of being part of a yacht club.
To continue reading this article or issue you must be a paid subscriber. Sign in
Subscribe to Practical Sailor
Get full access to Practical Sailor - over 4,000 articles - for just $34.
Subscribe today and save 42% off the annual rate.
A few small details that might help. All stuff I’ve tested.
Toilet. PG antifreeze will damamge neoprene joker valves (Jabsco heads), but EG (engine type) will not. Also, nitrile jokers, such as used in Raritan heads, are not affected by PG. See PS articles on the topic.
There is nothing wrong with flushing antifreeze, but to protect the vulnerable intake side of the pump, the antifreeze must be pulled in through the intake or at least through a T in the intake hose. Otherwise, you have only protected half of the head. Alternatively, there is a
drain plug in the head.
Fuel Treatment. PS testing shows that Star Tron is more effective than Sea Foam for diesel storage. It works well along side bug treatments, such as Biobor JF. For gasoline, the top choices are Biobor EB, Stabil 360 Marine, and Merc Quick Stor.
Water System. I might suggest a slightly different approach, since rinsing antifreeze out of the freshwater tank is nearly impossible. It just keeps diluting. Also, dilute antifreeze in the water tank often ferments, resulting in nasty tastes come spring. This approach is easier and results in a fresh water tank in the spring.
* Clean, empty and DRY the tank. Use a shop vac. Leave the top open until it is dry. You always put dinner dishes away clean and dry.
* Install the antifreeze in the pump and piping through a T located adjacent to the tank. No antifreeze enters the tank.
* Consider draining the heater and installing a bypass line for winterizing. Most chandleries carry these. A water heater takes a LOT of antifreeze.
* Never put diluted antifreeze in the water tank or any other place. It will ferment over the winter and result in nasty tastes in the spring. A dry tank does not need antifreeze.
Thanks for taking the time to share your experience Drew.
I was not aware of Star Tron product and will indeed look it up. I’ve used SeaFoam, K100 and Biobor JF together for more years than I can remember with great results.
I use plumbing antifreeze that does not damage any plastic or rubber components. When flushing toilet, I do pump anti freeze through the water intake thru hull. But I make sure my electric toilet is free on any residual antifreeze as recommended by Jabsco.
My former life was in the engine coolant industry, with lots of testing and and a few commercial formulations to my name. This is a core area.
In general, plumbing antifreeze (PG) is more damaging to neoprene head parts than EG (automotive antifreeze). The effect of both chemicals on the treatment works and the environment is basically the same and both are consider non-hazardous by the fish and wildlife department. If you check the toxicity to fish and marine life in PG and EG SDS you will find that they are very close, with EG, surprisingly, slightly less toxic. EG is quite toxic to mammals, but not so much to the environment and it breaks down very quickly. Thus, EG is safe and probably preferable for winterizing the head, but not for any system related to potable water.
Alcohol-based antifreeze is actually not bad on rubber parts, but can harden PVC hoses over many years. It evaporates and ferments slightly more quickly, so no thanks.
EG rates excellent for neoprene, nitrile, and plasticized PVC.
PG rates only fair for neoprene and excellent for nitrile and plasticized PVC.
Ethanol rates excellent for neoprene, nitrile, and good for plasticized PVC.
Excellent is what you need for long life, good will work for gaskets and some non-moving, non-stressed parts, and good won’t last very long. Lower ratings generally fail within days or hours.
Winterizing with PG is probably the leading cause of premature stiffening of neoprene joker valves and engine freshwater pump impellers. I ruined a few that way and learned. The effect is remarkable. In fact, there are technical reasons why even in this age of environmental concerns, EG remains favored over PG by all passenger car manufacturers.
It’s a pet subject. Sorry for the long report.