Properly winterizing a boat protects it from freezing temperatures, corrosion, and moisture damage during the off-season. Here is a comprehensive guide to preparing a boat for winter storage.
1. Engine Maintenance
The engine is the most critical and expensive component to protect against freezing and corrosion.
Change the Oil and Filters: Old oil contains acids and moisture that can corrode engine parts over the winter. Change the engine oil and the oil filter. For sterndrives and outboards, change the gear lube in the lower unit; if the old lube looks milky, water has entered the system, and the seals need professional inspection.
Flush the Cooling System: Flush the engine with fresh water to remove salt, dirt, and debris. Most have drain plugs that can be easily removed, refer to your engine user manual to find. Once flushed, run marine-grade, non-toxic antifreeze (propylene glycol) through the cooling system until it exits the exhaust to ensure no trapped water freezes and cracks the engine block.
Fog the Engine (Carbureted Engines): Spray fogging oil into the air intake and cylinders while the engine is running until it stalls. This coats the internal components with a protective layer of oil to prevent rust. (Check your manual if you have a modern fuel-injected engine, as some do not require fogging).
2. Fuel System Care
Untreated fuel can break down in as little as 30 days, causing buildup and damage.
Add a Fuel Stabilizer: Pour a quality marine fuel stabilizer into the tank. I like to use Sea Foam, just because i have had great results.
Fill the Tank: Top off the fuel tank to about 90% capacity. This leaves just enough room for expansion but eliminates the empty space where condensation (water) can form during temperature fluctuations.
Run the Engine: Run the engine for 10–15 minutes to ensure the stabilized fuel circulates completely through the fuel lines and engine.
3. Plumbing and Water Systems
Any left-over water in the boat’s plumbing will expand when frozen, bursting pipes and cracking tanks.
Drain All Water: Completely empty the freshwater tank, hot water heater, and raw water washdown systems.
Add Antifreeze: Pump non-toxic marine plumbing antifreeze through all the lines, faucets, and showers until you see the colored antifreeze coming out of the fixtures.
Winterize the Head (Toilet): Pump out the holding tank at an approved facility. Flush the head with fresh water, then flush marine antifreeze through the system.
4. Battery and Electrical Storage
Cold weather will drain and potentially ruin a marine battery if left unattended.
Remove the Batteries: Disconnect the batteries (negative terminal first), clean the terminals, and remove them from the boat.
Store Properly: Store the batteries in a cool, dry place on a piece of wood or plastic (not directly on concrete).
Maintain Charge: Connect them to a trickle charger or a marine battery maintainer to keep them fully charged throughout the winter.
5. Cleaning and Protection
Leaving dirt or moisture on the boat will lead to mold, mildew, and permanent stains.
Deep Clean: Scrub the hull, deck, and interior. Clean all canvas, vinyl, and carpets, and ensure everything is completely dry before covering.
Remove Gear: Take home anything that can hold moisture or attract pests. This includes life jackets, flares, fire extinguishers, cushions, towels, and removable electronics.
Prevent Mildew: Place moisture absorbers (like DampRid) or a mild mildew-control product in the cabin and storage lockers. Propping open lockers and interior doors allows for better air circulation.
Wood boats require a unique exterior inspection, and possibly sanding, wood repair and new staining and varnishing, and bottom special coating.
6. Covering and Storage
Cover the Boat: Use a high-quality, breathable, custom-fit cover to keep snow, ice, and animals out. Ensure the cover is supported by poles so water doesn't pool in the center.
Consider Shrink-Wrapping: For outdoor storage in harsh winter climates, professional shrink-wrapping offers the best protection against the elements, provided it includes proper ventilation to prevent trapped moisture.
About the author: Tony Sampair and The Luxury Lake Team at Lakeplace.com are the #1 locally and regionally dominant experts for the most coveted waterfront markets. From the historic Stillwater to the shores of White Bear Lake to Bald Eagle Lake & the premier properties of Forest Lake and the Chisago Lakes area, Tony Sampair has sold over 500 properties in this specific area, in his 40 year career, he also makes White Bear Lake his home on the shores of Bald Eagle Lake. No other agent has more sales volume or experience in this area than Tony Sampair. Tony is truly the #1 Real Estate Agent in the NE metro lake area of St. Paul & Minneapolis. Tony also is the General Manager for LakePlace.com, and manages the entire states of agents in MN, WI, & MI, with our LakePlace expert agents ready to serve you in your search.
