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Shrink-wrap vents

Vent in place on shrink-wrapped boat.

Help that plastic cover breathe this winter

Vent in place on shrink-wrapped boat.
Vent in place on shrink-wrapped boat.

Issue 63 : Nov/Dec 2008

Those of us who defend our boats against Ol’ Man Winter with that distinctive blue or white shrink-wrap cover are aware of the importance of providing ventilation. There needs to be a method of wicking out the moisture that can accumulate under the cover.

I’ve seen some primitive vents made out of leftover scraps of shrink-wrap plastic, but there’s a free alternative that works very well.

The basic materials for making a shrink-wrap vent are shrinkwrap tape (not shown) and a clean empty plastic jug. Cut a shape depicted by the dotted lines, making sure to leave some of the jug bottom on for stiffness. Cut two of these pieces from each jug.
The basic materials for making a shrink-wrap vent are shrinkwrap tape (not shown) and a clean empty plastic jug. Cut a shape depicted by the dotted lines, making sure to leave some of the jug bottom on for stiffness. Cut two of these pieces from each jug.

Here’s how

  • Take a couple of empty RV/marine antifreeze jugs. You probably used these to protect your water lines. If you didn’t keep the empties, you can do a little dumpster diving to retrieve someone else’s discarded jugs.
  • Cut out two (almost) heart-shaped pieces per jug, as shown in the picture to the right. Leave on some of the jug bottom curve for stiffness. Cut rounded corners on the bottom to guard against chafe.
  • Use shrink-wrap tape to tape the left and right sides of the vent onto the vertical surfaces of the stretched and fitted shrink-wrap cover.
  • From inside the cover, find the vent area, and cut a 2-inch hole in the stretched wrap directly behind the attached cover.

Add about six vents for a 30-foot boat. The plastic vent keeps water and snow from entering the hole; the rigid jug bottom curve keeps it open.

Joseph Orinko has sailed the waters of Presque Isle Bay and Lake Erie for 26 years, 20 of them in his O’Day 23, Unicorn, and six seasons in a Catalina 30 named Unicorn.

Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com

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