Winterization Tips
Boaters in northern climates of the US start preparing, mentally and physically, for winter storage every year around October 1st. The winterization process is not the same for all boaters, but there are certain services that should be completed annually. Depending on type of boat (power/sail), engine package, systems onboard, and type of storage - a winterization checklist will vary. This post highlights recommended services, and tips I’ve provided Chicago boaters over the years while preparing for winter storage.
Basic annual off-season services should include: fluid and filter changes, flushing the engines and all systems that have or hold water, drive service (for I/O boats), and battery maintenance.
Oil and oil filter changes are critical to keep your engine(s) functioning optimally. They ensure that the engine is properly lubricated and should be scheduled every 100 hours for gasoline engines or 200 hours for diesel engines. However, I recommend end-of-season oil changes regardless of how many hours were added. This way the fresh oil can cycle through the engine prior to sitting for months in storage. New boats/engines are slightly different and need a “break-in” oil change usually after 10-20 hours, which may be required to maintain warranty. Tip: while an engine is under warranty it is best to use OEM parts and a certified technician or dealer to perform the service.
Fuel filters should also be changed at the same time as the oil filters. Bigger diesel engines may have multiple fuel filters – primary/by-pass, or an additional fuel filtration system altogether. Dirty fuel filters will cause engine performance issues or worse if left unchecked. Tip: fill your fuel tanks, or at least 3/4 full, prior to storage and add fuel stabilizer/additive during the fill up. This will greatly reduce fuel-related issues like water, bacteria, or sludge build-up during storage.
Flushing your engine and the water systems with a non-toxic propylene glycol-based antifreeze will protect against frigid temperatures. Not all antifreeze is the same, and depending on whether you’re storing inside heated, inside cold, or outdoors you’ll want to choose the best option – here’s a link to help. For folks storing outside this process must happen! Below freezing temperatures will cause catastrophic damage to unprotected engines, water systems, and anything else that holds residual moisture. Using a marine-grade propylene glycol-based (PG) antifreeze with rust inhibitors, on engine and freshwater system is best because it will not evaporate like ethylene glycol-based (EG) antifreeze and it’s non-toxic. Bonus, it does not smell as bad when flushing the freshwater system at the beginning of the season. Antifreeze is classified by their bust points and the most common are -50, -100, and -200. Tip: even storing indoor heated it’s recommended to flush engines with antifreeze due to the added protection of the corrosion inhibitors.
Drive service for stern drive powered boats (I/O) is also recommended annually per manufacturers (Mercury/Volvo). The service can only happen while the boat is out of the water and is the only way to know if there are issues with the drive. During drive service, the drive is pressurized, seals and fittings are checked, gear oil is changed, and the bearings/fittings are greased before reinstalling back onto the boat. Tip: at minimum the gear oil and drain screw gaskets should be changed prior to spring.
Battery maintenance is critical for the off-season! Marine batteries are your boat’s lifeline and should be tended to throughout the season, but especially during storage. There are several types of batteries that perform different functions on your boat. Knowing where they are located, how many are onboard, and ideally what they do is very helpful. Main tips for battery maintenance during storage: fully charge your batteries – aim to keep them above 11.7 volts, while in storage completely disconnect the batteries, clean off the tops of the batteries – access dirt/liquid can lead to discharging, and if replacing a battery within a bank (multiple batteries tied together) it’s best to replace the entire bank. This will prevent the “new” battery to compensate for the “older” batteries, and eventually burn out. Periodically charging your batteries leading up to spring will ensure that the boat starts after hibernating all winter. Marine batteries are designed to withstand the rugged conditions and elements associated with boating – auto batteries should not be used to power your boat! Here’s a link to help explain the functionality of the different types of batteries.
Final tip, going into the off-season with a maintenance gameplan is huge! Winterization services should be performed, or requested/scheduled, as early as possible so you’re not stuck in storage longer than necessary. New boaters can be taken aback by the amount of work that goes into an off-season and being ready early on – especially when scheduling service makes the process much smoother. There’s nothing worse than delaying off-season tasks, or service that unfortunately leads to launch delays!