It’s fall, and that means it’s shrink wrap season. In my part of the world marine dealers are frantically racing freezing temperatures and impending snow, winterizing boats and sealing them tight in yards of blue and white plastic. The process of shrink wrapping has become a common, final step in the off-season storage regime, not just of boat owners in the snowbelt, but across the country. Sealed tight, a shrink-wrapped boat is protected from rain, snow and dirt and ready to be stored for months – or even years – right out in the elements.

Shrink wrap season is in full swing. The protective plastic can be applied to almost any boat.

Because it requires some special tools, and materials generally only sold in very large quantities, shrink wrapping is probably not a job you are going to tackle yourself. Many marine dealers offer this service, usually charging by the foot of boat length. In my Wisconsin neighborhood, the rate is $9.00 to $10.00 per foot, with a discount offered for boats stored on the marina property.

My Long Island correspondent reports that dealers there now package shrink wrapping with boat winterization, based on a fee schedule that includes the number of boat engines, boat length and other factors. So you put your boat in the hands of a professional, but to make sure the job is done correctly, it helps to understand the procedure and some of the common mistakes that are made when boats are wrapped. There are also some things you can do to your boat before it’s wrapped that will help prevent issues over the winter.

After constructing a support frame, Eric Doberstein of Spellman’s Marina in Oshkosh, Wis., measures the boat before cutting a length of shrink wrap material off of a large roll.

For expert advice, I’ve turned to Dr. Shrink, perhaps the largest supplier of shrink-wrapping materials in the world. Located in Manistee, Mich., Dr. Shrink sells wrap not just for boats but also for a wide range of industrial applications, like wrapping an entire building, or a locomotive. To get the skinny on boat wrapping, I spoke to sales manager Ryan Polcyn, who is featured in a how-to video on the Dr. Shrink website that offers a great tutorial on runabout wrapping – he’s the guy doing the work. The site also has lots of tips on prepping powerboats and sailboats for wrapping. Study the site and you’ll know as much about installing wrap as the guys at your marina.

Polcyn says the number one problem he encounters with shrink-wrapped boats is moisture accumulation.

The sheet of plastic material is laid over the boat and the support frame, and the side edges are trimmed.

“The shrink-wrap material is non-permeable, so it’s important that the boat is as dry as possible before it’s wrapped, and that vents are installed in the wrap so it can breathe during storage,” says Polcyn.

You can help in this regard by cleaning out the boat before dropping it off for wrapping. It’s a good idea to get any old food wrappers, bait cups and other items that might attract rodents out of the boat anyway. Polcyn said damp PFDs are a common source of moisture. You want to pull all gear out of storage compartments, let them dry out, and then leave the hatches open while the boat is stored. Pull the drain plug so all water can run out of the bilge. Bags of desiccant and mildew gas bags can also be left in the boat to fight moisture issues. The Dr. Shrink site suggests that all wrap jobs should be vented. I don’t see many wrapped boats here in Wisconsin with vents, however. Maybe it’s so cold here that everything goes inert anyway. But the vents only cost a few dollars each and are easy to install. The Dr. Shrink tutorial also shows how to install a vent over the boat’s fuel tank vent, another feature I don’t see often in the field. Polcyn says he doubts that enough gas fumes would accumulate under the wrap to be explosive, but venting the tank to the atmosphere can keep the boat from smelling like gas in the spring.

The bottom edge of the plastic is wrapped under a cord stretched around the boat, and the propane torch is used to weld the material together. The applicator wears a heavy glove so he can pat the material to secure the weld.

Constructing a proper support structure is another key to wrapping success, says Polcyn. You need to build a ridge in the center of the boat with 2x4 lumber, and it should be supported with the same cord that’s used to secure the bottom edge of the wrap around the boat. The top of the support should be padded to keep the wrap from chafing through. I’ve seen carpet scraps used for padding.

“The more pitch in all directions the better when building the support,” says Polcyn. “You want rain and snow to slide off the wrap, and not collect anywhere over the boat.”

After the bottom edge is secured, heat is applied to the material on top of the boat, which shrinks and stretches tight, creating a taut, tent-like cover over the boat. Rain and snow will slide right off the slick plastic is the pitch is steep enough.

The support needs to be at least 10 inches higher than the boat windshield. Even the lightest-gauge wrap material can hold more than 250 pounds, says Polcyn, but you don’t want that much weight to be resting on the windshield frame. Shrink wrap should never be used on boats with Imron-type paint on the hull, as the heat required to seal the wrap will damage the paint. It’s also important to keep the flaming heat gun away from bottom paint.

You might have a choice of wrap colors. I see white and dark blue in my area. Polcyn says the white wrap reflects more heat and results in less condensation, and is the right choice in warmer climates. The blue wrap absorbs heat, which helps snow melt and then slide off the wrap. In the process of wrapping a boat, it’s not uncommon for a few holes to appear in the wrap, usually because it was over-heated. Polcyn says that it’s perfectly OK to repair these holes with shrink wrap tape.

I asked Polcyn about wrapping over an outboard motor, and he says there’s no clear policy to follow. It’s never a good idea to cover an outboard with a tight plastic wrap or a tarp (I’ve seen garbage bags sealed with duct tape over motors on stored boats) because condensation will form under the cowl and can cause electrical and corrosion issues. If it were my boat, and the shrink wrap could be applied between the motor and the boat transom in a way that the boat is sealed, I’d go that route. If the motor is wrapped, make sure air can circulate up under the motor, and maybe cut a hole in the wrap at the vent in the back of the outboard cowl.

Dr. Shrink sells this shrink wrap disposal bag with a pre-paid UPS shipper that delivers the material to a recycling facility in Minnesota. Last winter’s shrink wrap becomes next summer’s composite dock decking.

Polcyn also notes that quality shrink wrap is also treated with a UV filter, so it protects the boat interior from sun damage. Shrink wrap can also be used to protect a boat before it’s shipped a long distance. I once towed a boat from Seattle to Homer, Alaska, and had the boat wrapped to protect it from gravel dust and stone chips. When we got to Homer, we pulled off the wrap and the boat was perfectly clean. Polcyn notes that for highway transportation, it’s not necessary to build a support structure, but that venting to relieve air pressure under the wrap is critical. Polcyn says that his wrap material has a typical warranty of 24 months. “In Florida or Arizona, it will last 24 months,” he says. “Here in Michigan, where the UV is less intense, it can look great after five years.”

Finally, come spring you don’t want that huge sheet of polyethylene to end up in a land fill. It can be recycled. Dr. Shrink has a dedicated program called the Rebag Recycling System, which consists of a bag big enough to hold 600 square feet of wrap (enough for a 26-foot boat) that has a pre-paid UPS label. You stuff the wrap in the bag and drop it off either at UPS or at a participating dealer, and it will land at a facility in Minnesota and be turned into synthetic deck lumber. If a dealer is going to un-wrap your boat, please make sure they are not putting the wrap in a Dumpster. You can order a recycling bag through a dealer or directly from Dr. Shrink. The $25 cost is mostly for the UPS shipping.

Editor's Note: Learn more about Protecting Your Paint Job When Covering Your Boat in this Boats Blog post about shrinkwrapping with Awlgrip-painted hulls.

plueddeman-head-shotCharles Plueddeman is's outboard, trailer, and PWC expert. He is a former editor at Boating Magazine and contributor to many national publications since 1986.