Here’s your step-by-step guide to winterizing your boat

By Jim Ehrman, Lake Erie Rear Commodore

Photos courtesy of Jan Vitucci-Ehrman

Hard to believe September has already arrived. Time for us to put away our whites (although I’ll never understand why I can’t wear them after Labor Day) and think about getting the boat out of the water.

Whether you have a trailer boat or a large cruiser, haul out is a very busy time with many things to do to prepare the boat for winter. Some boaters hire out the job. Many boatyards and marine companies offer winterization services. Others prefer the DIY route.

Whichever route you choose, the same tasks need to be completed. The following is a checklist of sorts, which you may use as a guide to getting the job done right.

• Clean the boat inside and out.
• Remove perishables and bedding. Some prefer to also remove cushions, towels, and kitchenware.
• Some boat owners also remove pricey easily stolen items like dock lines, fenders, and electronics, depending on preference and upon the security of wherever the boat is stored.
• Change engine and generator oil and filters. Why? Dirty oil has acids, and contaminants can damage engine parts if allowed to sit all winter.
• Whether you have gas or diesel engines, stabilize the fuel with a good stabilizer. Add the fuel stabilizer as you’re topping off the tank prior to storage. Be sure to avoid completely filling the tank. Five or six gallons shy of a complete fill should leave enough space to allow for expansion and prevent fuel from coming out the overflow.
• As always, gas engines should have ethanol-free fuel.
• You may want to consider spraying the boat to counteract the many creepy crawly creatures which like a nice place to hang out over the winter.
• Check all fluid levels.
• Pump out the holding tank.
• Drain the fresh water system. Don’t forget the freshwater system includes icemakers hot water heater/tank and washing machine (if your boat is so equipped)

When the boat comes out of the water, the hull should be immediately pressure washed. This is an opportune time to visually inspect the bottom paint, running gear, shafts, anodes, etc., all without having to bend over or otherwise contort your body to see the boat’s usually unseen parts. Now you know what below deck issues must be addressed before it goes back in the water.

All of those tasks are important for every boat prepared for winter storage. Outside cold winter storage requires additional work to safeguard the boat’s systems.

 If storing outdoors you will want to run antifreeze through the boat’s systems. The chemical in antifreeze which resists freezing is either ethylene glycol or propylene glycol.

Ethylene glycol is poisonous to humans, pets and wildlife and is difficult to properly dispose of. This is the chemical used in automotive antifreeze. Propylene glycol is biodegradable and non-toxic. Of course that means it is more expensive, but it is the better choice to use.

If storing outdoors:

• Run “red pop” (red propylene glycol) through the fresh water system. However, don’t put ANY propylene glycol in the toilet bowl as it can deteriorate sanitation hose linings.
• Leave the head and its lines empty.
• If the boat has a washing machine, put a small amount of blue propylene glycol in it and briefly run the washer to pull the fluid through the system.
• Air conditioners, engines, and generators also need to be winterized with blue propylene glycol. This propylene glycol acts as a lubricant for the impellers in the pumps of these machines.
• To prevent any residual fluids from freezing, winterize for the lowest expected temperature of your boat’s storage environment. In northern Ohio, minus-20-degree protection is usually adequate.

The labeling on the bottle of propylene glycol will likely have a temperature rating on it. Be sure you understand whether it is “freeze” or “burst point” protection. The freeze point is where ice crystals (slush) will form in the undiluted product.

Slush will not harm engines or fresh water systems. Burst point is what it says…a copper pipe would burst at the product’s undiluted temperature rating.

• After running the propylene glycol through the systems, test the temperature protection level with a refractometer.

DON’T use automotive testers found at the local car parts store because auto testers are designed to measure ethylene glycol that is in automotive systems. You’re winterizing your boat with propylene glycol.

You can readily find refractometers on Amazon. (Isn’t everything on Amazon? No wonder Jeff Bezos is a gazillionaire.)

• Remember potable water systems use “red pop” or red propylene glycol. Engines, generators, and AC units use blue propylene glycol.
• Consider putting an anti-mildew product such as Damp-Rid in various places in the boat.
• Leave all doors (including refrigerator and icemaker) and cabinets open to encourage air flow.
  
  • Protect your boat against the elements by having the boat shrink wrapped. Many people use tarps, but they can be very heavy and difficult to put on a boat. A good quality shrink-wrap provides better protection than a tarp. 

• • If the boat will be housed indoors in cold storage, systems still need to be winterized but no tarp or shrink wrap is necessary. Some people use painters’ plastic just to keep dust off the boat.

If the boat will be in indoor heated storage, it’s not necessary to winterize the fluid systems as long as the storage facility has a backup plan in case of a lengthy power outage. If you’re worried, you could consider winterizing for your own piece of mind.

Make sure the drain plug is out and put in a prominent place, so you don’t forget to put it back in. Then disconnect the batteries. Of course, you will periodically re-connect them when you re-charge the batteries over the winter.

At this point, the boat is “put to bed” in its winter environment. Whew! Even if your boat is in inside heated storage, it’s a good idea to occasionally check on it throughout the winter.

One never knows what oddities could occur—like the workers on the boat next to you slinging buffing compound all over your boat. Certainly, if the boat is stored outside, it’s important to check on it after a heavy weather event.

Rest assured you have done your best to take care of your boat. Take part in your favorite winter activities, like going to a boat show mid-winter. 

Know that spring preparation will be here before you know it and you’ll be able to enjoy your boat the following season.