As winter approaches, it’s important to prep your boat for freezing temperatures. If you don’t winterize your vessel, you could face some nasty surprises—like corrosion, a cracked engine block, burst pipes, and more—come spring.
If you’ve decided to skip this pre-winter ritual because you live in a warmer climate, keep in mind that every state experiences dips below freezing. Any freeze may be fleeting where you live, but the resulting damage to your boat could cost hundreds, or sometimes thousands, of dollars. So follow these seven steps to save yourself a bit of grief and regret the next time you want to enjoy a day on the water.
1. Prep the hull.
If you have a fiberglass boat, check the hull for any stress cracks, especially near the bow eye. If you spot any cracks, a pro can repair them. Additionally, be sure to inspect the hull for blisters in the gelcoat. If you find any, use the corner of a small chisel to puncture the blister and drain it. Then, sand it smooth, wipe the area with rubbing alcohol to remove debris, and patch it with an epoxy-based filler. Scrape any barnacles from the bottom of your boat, and give it a good power wash to remove lake or sea scum and debris.
2. Change the oil.
Moisture can accumulate in engine oil causing mischief ranging from poor fuel economy to engine failure. So changing your oil regularly—including pre-winter storing—is a savvy move.
3. Drain the motor.
When water lingers in your engine it can freeze and expand, potentially cracking components. To prevent such a calamity, which can be costly to repair, you’ll need to drain your engine prior to tucking your boat away for winter.
If you have an inboard or sterndrive engine:
- Use water muffs to connect a garden hose to your cooling system before flushing your engine with clean water to remove any saltwater or debris, which can cause corrosion.
- Refill with a mix of water and marine-grade antifreeze. (Follow the antifreeze directions for the proper ratio.) Then, run the engine for a while to circulate the antifreeze, which will provide a protective layer against freezing.
- Remove the hose and let the engine drain completely.
If your boat has an outboard motor:
- Suds up the motor with soapy water.
- Idle the motor and flush the inside with fresh water. (Your motor may have an attachment for a garden hose.)
- After flushing, rest the motor vertically to let all the water drain out.
4. Fog the engine.
To protect your engine’s innards from rust and corrosion, coat them with a fogging lubricant.
Remove the flame arrestor and, while running the engine at a fast idle, spray fogging oil down the carburetor. Then, with the engine stopped, carefully remove the spark plugs and spray some fogging oil into the cylinders.
Check your owner’s manual for the recommended fogging product. If your boat has a fuel-injected engine, fogging oil—which is pretty sticky—can get caught in an injector. For these motors, two-cycle oil works best.