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How to Maintain a Boat

How to Build a Boat Cover

Octagonal electrical boxes hold the frame together; insert setscrew connectors and tighten the locknuts.

Enclosed boat storage is expensive, but an unprotected boat ages quickly. Store your boat in your own yard with this lightweight, easily disassembled cover frame.

Tools: pencil, slip-joint pliers, rented conduit bender, scratch awl or grease pencil, hacksaw, screwdriver, staple gun, measuring rule, scissors or sharp utility knife.


Materials: 3 1/2-inch octagonal electrical boxes, 1/2-inch or 3/4-inch thinwall setscrew connectors, 1/2-inch or 3/4-inch thinwall electrical conduit, scrap wood blocks, scrap pieces of carpeting, heavy-duty staples, heavy plastic tarp, duct tape, sturdy cord.

Time: about 6 to 8 hours.

To calculate the materials you'll need, figure from the length of your boat. Divide the length of the boat by 3 and add 1; this is the number of 3 1/2-inch octagonal electrical boxes you'll need. Thinwall electrical conduit is sold in 10-foot sections; buy 1/2-inch conduit for small boats and 3/4-inch conduit for wide boats. You'll need sections for the support legs of the cover frame, for the ridgepole, and for snow support posts. Divide the length of the boat by 3 and multiply by 2; this is the number of sections needed for the support legs. Divide the length of the boat by 3; this is the number of ridge sections you'll need. Add 3 to 6 sections for snow support posts at the ridge-leg intersections, depending on how much snow falls in your area. Rent a thinwall conduit bender to simplify the frame assembly; get instructions from the rental agent.

To cover the boat, buy a heavy plastic tarp, at least 5 feet longer than the boat and at least 3 times as wide. Check at outdoor stores or industrial supply houses for the best buy. If possible, choose an opaque black tarp, to speed melting of piled-up snow.

Before you start work, plan the assembly of the cover frame, and sketch your plan so you can refer to it as you work. Space arched cover support legs over the boat at each end of the boat and every 3 feet along its length; connect the supports with a ridgepole. Brace the framework firmly with three to six support posts holding the top of the frame above the boat's deck.

Prepare the electrical boxes by removing the knockout plugs on the sides of the boxes; strike them sharply with the handle of a slip-joint pliers and then twist the tabs off with the jaws of the pliers. Insert a thinwall setscrew connector into each side opening of each junction box and tighten the locknuts firmly with the pliers.

Construct the support legs of the frame first. Insert a section of conduit into the conduit bender and align it with the edge of the bender; then make a 135-degree bend in the pipe -- 45 degrees out from a right angle -- as directed by the rental agent. Repeat to bend each support leg section of conduit. Insert two sections of conduit at the bent ends into the openings on opposite sides of an electrical box, making an angular tent shape; don't tighten the setscrews yet. You'll need an assistant at this point to determine the desired height of the legs.

Hold the assembled but not secured support over the boat, straddling the boat at a center support point so that the angled-out legs touch the edges of the boat. Adjust the support to the desired height over the boat and have your assistant mark the deck intersection point with a scratch awl or grease pencil. Cut the conduit legs at these points with a hacksaw; then reinsert the legs into the electrical boxes and firmly tighten the setscrews to hold them in place.

Repeat this procedure to place and cut each support leg, setting legs at the ends of the boat and every 3 feet along its length. The supports at the center of the boat will be higher than the supports at bow and stern, forming a pitched cover to shed snow and rain. Set each pair of support legs in order as you work so that you'll be able to assemble the frame in sequence.

When all the support legs have been bent and cut, cut 3-foot sections of conduit to form a connecting ridgepole from support leg to support leg. Assemble the conduit frame by connecting the support sections with 3-foot ridge sections; tighten the setscrews holding the connecting sections in place. At this point the frame will be a long tent-shaped skeleton that covers the length and width of the boat exactly.

Set the assembled frame onto the boat. To protect the boat, insert a block of scrap wood under each conduit leg. Pad the top corners of the frame and cover the electrical boxes with pieces of scrap carpeting, wrapped around and stapled together with a staple gun and heavy-duty staples.

The completed frame is braced on the deck; tape tie-down tabs hold the plastic cover to the boat trailer.

To complete the framework, add three to six snow support posts, depending on the snow load in your area and the deck or cockpit you're working over. At each support point, where the support legs and the ridge sections are connected at the sides of an electrical box, measure the distance from the bottom of the box to the deck or cockpit directly below it. Cut a section of conduit to the measured distance and connect it to the bottom opening of the box with a setscrew connector, forming an upright brace inside the framework. Set a block of scrap wood under the brace to protect the deck.

With the completed frame in place over the boat, spread a heavy plastic tarp over the frame to cover it entirely. The tarp must extend at least 1 foot past the deck all around; if the boat is any color but white, cover the entire hull, if possible, to prevent fading.

To secure the tarp over the framework, attach a tab of duct tape every 2 to 3 feet around the boat. For each tab, cut a piece of duct tape about 1 foot long. Stick 4 inches of one end of the tape to the outside of the plastic tarp and fold the tape over on itself to stick 4 inches at the other end to the inside, with a double 2-inch-long tab of tape sticking out beyond the edge of the plastic. Cut a small hole in each tab with a scissors or a utility knife.

Attach the tarp to the boat trailer with sturdy cord, cut as needed and looped securely through the duct tape tabs. Be careful to fasten the cover down securely, with no loose or flapping edges; strong wind could damage a poorly secured tarp. Disassemble and reassemble the cover frame as needed each season.

Keeping your boat seaworthy, attractive, and comfortable need not be a worry. Follow this article's advice, and you'll be smooth sailing all the way.

For tips on caring for and repairing other types of sports equipment, try the following links: