Boat Winterizing Tips from the Experts

As warm summer weather transitions to cool fall temperatures, boat owners begin to think about winterizing their sea vessels.

Most boaters know the basics: drain the boat of all water, pour stabilizer into the fuel tank, use fogging oil to prevent engine rust and flush antifreeze through the engine, motor and water pipes. Hiring a professional may be the best way to ensure that your boat continues to operate come springtime.

But for those insistent on doing their own winterization, local professionals have offered the following tips to help avoid major damage – and repair costs – come next season.

Fill ‘er up – but not too much. Filling the boat with gas all the way up to the vent can be hazardous, as on hot days the fuel will expand and leak out of the vents, said Kelvin Salis, owner of Marina. On the flip side, you don’t want the level too low either because too much space will allow too much moisture to condense in the tank. Wade Newman, a mechanical technician at , recommends filling the tank up between three-quarters and seven-eighths full.

Use stabilizer before haul-out. Everybody knows to put stabilizer into the fuel tank. But it’s a good idea to begin using stabilizer around the Labor Day weekend, and then continue running the boat with the stabilizer in it, Newman said. If you dump the stabilizer into the tank right before storing it, it will treat the fuel in the tank but won’t do much for the fuel lines, fuel pump and carburetor. This can be an especially large problem if the boat isn’t put back into operation next year. In fact, Newman recommends using stabilizer year-round.

Check the closed cooling side of the engine. Larger gasoline and diesel engines will have a closed cooling side. When winterizing closed cooling systems, check the freeze protection in that side, Newman said. There’s a conventional-looking radiator cap, and you can test your sample right there. Not having freeze protection may lead to cracking of the engine or heat exchanger.

Remove liquid-filled gauges. It only makes sense to remove electronic devices like GPS and radar units, marine radios and depth-finders before storage. The cold is terrible for them, plus there’s always the chance they could be stolen if left unattended, said Lt. Brian Barlog, commander of the Macomb County Sheriff’s Marine Division. However, Newman also recommended taking out liquid-filled dashboard gauges. The chemical liquid inside them – which is used to stabilize the needle and prevent fogging in the gauge – can freeze.

Is removing the battery a good idea? While disconnecting the negative battery terminal is a must, there seems to be some variation among boaters as to whether to take the battery out. Most people don’t remove the batteries, and in the vast majority of cases, the batteries end up being OK. But Newman said it’s a good idea to take it out, put it in the garage and put it on a trickle charger. The batteries will give off fumes, so if you live in an apartment, condo or anywhere without an out-of-the-way storage area, leave the batteries in the boat. Fully-automated trickle chargers can be left on all the time, while the typical 2- or 6-amp automotive battery charger sold at retail stores should be used monthly.

Just because the boat is being stored in a heated indoor facility doesn’t mean it shouldn’t be prepped at all. The battery needs to be disconnected and it should be kept clean and dry during storage. The engine needs to be fogged, the fuel needs to be stabilized and it should be covered with loose-fitting covering like Visqueen.

Shrink wrapped boats should be well vented. Most boat owners choose to shrink wrap their boats because it seals the boat better and ice doesn’t cling to the wrap as it does to canvas. There are various powders and devices that can be placed in the boat to absorb moisture, but even with those you’ve got to keep it vented. “I’ve seen shrunk wrapped boats that were not vented, and by the spring the interiors were spotted with black mold everywhere. They couldn’t get it out – thousands of dollars’ worth of damage,” Newman said.

Lastly, whether you’re a do-it-yourselfer or not, don’t delay too long. Some boat owners want to enjoy the late summer boating weather, but nostalgia for those beautiful days on the lake doesn’t justify putting off winterization too long. Michael Bennett, of M&G Marine Services Inc., said some boat owners will frantically call for winterization services only after winter’s first freeze. Waiting that long may lead to damaged water systems, which tend to break first, Bennett said.