Winterizing Your Boat: Essential Steps For Cold Storage

Winterizing your boat is essential to protect it from damage during the colder months. While it may seem like a daunting task, it is worth it to avoid costly repairs and to extend the life of your boat. The process involves several steps, from flushing and draining the engine to changing the oil and protecting internal engine components. One of the most important steps is to stabilize the fuel, as fuel can deteriorate, causing gum and varnish build-up, which can lead to hard starting and poor performance. Additionally, it is crucial to remove all water from the boat to prevent freeze-damage and the growth of mould and mildew. Other key steps include greasing and lubricating engine parts, removing valuables, and cleaning and waxing the exterior. By following these steps, you can ensure your boat is ready for the winter and will be eager to go in the spring.

Drain the engine and add antifreeze

Water is the biggest danger to your boat during the winter. If water freezes, it expands, and this can lead to cracked engine blocks and manifolds. Even a short freeze can cause expanding ice to crack a manifold. Therefore, it is important to drain the engine and add antifreeze.

Inboard Engines

To drain the engine of an inboard engine, you can either open the petcocks or remove plugs, or you can run antifreeze through the system. If your boat remains in the water during winter, you will need to close the intake seacock and remove the intake hose from it. Then, submerge the end of the hose in a bucket of antifreeze and run the engine until the antifreeze comes out of the exhaust ports. It is important to bring the engine up to operating temperature before running antifreeze through it, as otherwise, the thermostat will block the flow to some cooling passages.

Stern-drive Engines

Stern-drive engines can be more complex to winterize than outboards, as you have to get the water out of the engine's block as well as the drive unit. You will likely need to remove block plugs to allow water to drain from the engine and remove sediments and scale. You may also need to run antifreeze through the drive and engine.

Outboard Engines

Outboard engines are designed to drain all water from their cooling systems when tilted in the down position. Therefore, the first step is to tilt the engine down and leave it there. It is a good idea to cover the engine, but make sure there is enough ventilation to prevent condensation from forming.

General Advice

When running antifreeze through the engine, it is important to ensure the engine reaches operating temperature so that the thermostat is open before adding the antifreeze. This can be difficult in cold weather, and one method is to remove the thermostat, which is a simple job on most engines. It is important to remember to reinstall it in the spring, along with a new gasket.

It is also crucial to use the correct type of antifreeze. While ethylene glycol is effective, it is highly toxic. A better option is to use propylene glycol, which is less toxic.

Stabilise fuel

Fuel is the number one cause of engine problems after seasonal storage. Fuel that is left untreated can lead to varnish buildup, clogged injectors, and other issues. To stabilise your boat's fuel before winter, follow these steps:

Step 1: Plan your late-season boating

Plan your late-season boating trips so that you use up most of the current fuel in the boat's tank. This will ensure that you have as little fuel left over as possible when you fill the tank with fresh fuel for storage.

Step 2: Fill the tank with fresh fuel

Fill the tank with fresh fuel so that it is almost full. It is recommended to use gasoline that does not contain ethanol if that product is available where you live. This is because ethanol blends can absorb moisture, which can cause issues with your fuel system.

Step 3: Add a marine fuel stabiliser

As you fill the tank for storage, add a marine-specific fuel stabiliser additive to the fuel. Follow the instructions on the bottle for the correct dosage and application method. Fuel stabilisers help to prevent the formation of harmful gum and varnish and protect your engine during storage.

Step 4: Run the engine

After adding the stabiliser, run the engine for a few minutes to distribute the treated fuel throughout the fuel system. This can be done either when the boat is in the water or while using a fitting designed to run the engine with a garden hose.

Step 5: Go for a short boat ride

Next, give the boat a short run on the water to further distribute the treated fuel. This step is especially important for boats powered by gasoline outboard, sterndrive, or inboard engines equipped with a carburetor rather than fuel injection.

By following these steps, you can help ensure that your boat's fuel system is protected during the winter and that your boat will be ready to go when the warm weather returns in the spring.

Protect internal engine components

During storage, engine oil drains away, which can leave internal engine components exposed to harsh winter elements. This can lead to corrosion and cylinder scuffing when the boat is used again in the spring. To prevent these issues, you can take the following steps:

First, use a fogging oil spray or aerosol fogging solution. This product is designed to penetrate deep into the engine and coat parts with a protective layer of anti-corrosive compound. Remove the engine cover and spray the fogging oil into the carburetor inlets and spark plug holes. Start the engine and slowly spray the fogging oil into each of the inlets.

Second, if you have a four-stroke outboard, the engine oil and filter should be changed every 100 hours or once a season. Storing the motor with old oil can expose internal engine components to moisture and acidic combustion byproducts, which can cause corrosion. Check your owner's manual for the recommended lubricant products for your marine engine.

Third, if you have a direct fuel-injected (DFI) two-stroke engine, squirt one ounce of DFI outboard oil into each cylinder through the spark plug hole. Put a coat of anti-seize lubricant on the spark plug threads before carefully replacing the plugs. Use new spark plugs, correctly gapped, per the service schedule in your owner's manual.

Finally, if you live in an area where you can run the engine every few weeks, additional winterization steps may not be necessary.

Clean and cover the boat

Cleaning and covering your boat is an important step in the winterization process. Here is a detailed guide on how to do it:

Cleaning the Boat:

• Start by removing all valuables, including expensive electronics, bedding, clothing, and removable seat cushions.
• Take out all gear and equipment, such as fishing rods, life jackets, and tackle boxes.
• Empty and clean all storage compartments, lockers, and closets.
• Defrost and clean out the refrigerator and freezer, and apply a coat of protective wax to all exposed surfaces.
• Spray vinyl seats and covers with mildew spray.
• Deep clean any appliances, carpets, and floors.
• Turn pillows and cushions on their sides to allow for proper air circulation.
• Clean the hull, deck, and all hardware and trim.
• Wash the boat with soap and water, and rinse it thoroughly.
• For fibreglass boats, inspect for blistering and address any issues.
• Clean the windshields and other fabrics such as drop curtains, Isinglass, and bimini tops.
• Ensure all canvas is dried thoroughly before storing it neatly. If possible, remove all canvas and store it indoors.
• Remove marine batteries and store them in a cool, dry place.
• Check the battery terminals and apply a light coat of grease if needed.
• Check and recharge the battery regularly during storage.
• If your boat has an inboard engine, change the oil and oil filters, and flush the engine with fresh water.
• For outboard motors, flush the engine with fresh water and wash the motor's exterior.
• Drain the fuel from the carburetor and lubricate all parts.
• Apply fogging oil to the pistons and cylinders of the outboard motor.
• Use water-resistant grease on the propeller shaft and threads.
• Lightly wax the engine's exterior.
• Change the gear oil in the lower unit.
• Inspect and clean the stern drive, removing any barnacles or plants.
• Check for cracks or pinholes in the rudder boot.
• Drain and wash the exterior of the gear case, and grease all fittings.
• Check the fluid levels in the lift pumps or hydraulic steering.
• Fill the fuel tanks to avoid condensation buildup, and add a fuel stabilizer.
• Change the fuel filter and water separator.
• Empty and clean the bilge, and spray it with lubricant to displace moisture.
• Add antifreeze to the bilge if there is any remaining water.
• Drain all freshwater systems, including tanks and heaters, and run non-toxic antifreeze through them.
• Open all faucets and showers and run them until you see antifreeze coming out.
• If your boat has a head, empty and clean it, and add antifreeze to the holding tank, hoses, macerator, and y-valve.

Covering the Boat:

• Use a durable cover to protect your boat from the elements.
• Tarps are a popular option, but they may not provide a perfect fit, leaving gaps that expose the boat to the weather.
• Shrink-wrapping is a more expensive option that provides a tighter seal and better protection.
• Store your boat under a canopy or in a garage if possible, or choose a location that minimizes exposure to wind, weather, leaves, and sunlight.
• Keep the cover clean and free of snow, debris, and water.
• Regularly check the cover and tighten it as needed to ensure it remains secure.

Remove valuables

When preparing your boat for winter, removing valuables is an important step. Boat yards are less frequented during the winter months, making it easier for thieves to break in. Therefore, it is in your best interest to remove all valuables, including expensive electronics, from your boat.

It is also a good idea to remove any loose gear that could get damaged. Gather all equipment on board, such as life jackets, flares, fire extinguishers, etc., and inspect them to ensure they are in good working condition. Remove any items that are not in good condition and make a note to replace them before the next boating season.

If you have a narrowboat, it is crucial to secure it properly when leaving it moored over the winter. Check the ropes for wear and tear and expect higher water levels, which may require adjustments. Ensure the boat is securely locked, and consider additional security measures such as alarms or CCTV.

Finally, don't forget to insure your boat, even when it's not on the water. Boat insurance can help protect your vessel and personal gear, providing peace of mind while you enjoy your time on the water.

Frequently asked questions