7ft Wooden Sailboat

by NateO4 in Outside > Boats

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7ft Wooden Sailboat

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I built this 7-foot working sailboat using 1x4 pine and quarter-inch thick plywood. Boat building is something anybody can accomplish. All you need is about $100 in tools, $200 in materials and perhaps 60 hours of spare time. I'm not a professional carpenter, so do proceed at your own risk. Hopefully this broad overview will inspire you to take up this rewarding hobby.

Obtain Materials

Tools:

  • Jigsaw
  • Power drill: I prefer two, one with a drill bit for pilot holes and one for Phillips head screws.
  • Tape measure
  • Ruler and pencil
  • Power sander
  • 10-20 clamps of all variety: The more you have, the easier construction will be.
  • Scissors

Materials:

  • 2 4'x8' 1/4" plywood panels: No need to go for the expensive stuff. Non-marine grade oak worked fine for me.
  • ~20' of 1"x4" pine chords: For the structure and deck.
  • 3 2"x2" pine chords: For the oars and mast.
  • 1 12"x24" board: For the rudder.
  • 1 2'x2' 1/2" plywood panel: For the paddles.
  • 100' of synthetic rope. Synthetic is less affected by water.
  • 1 bed sheet: The sail.
  • 1 piece of tagboard: The stem.
  • 3-4 cans of spray-on Spar Urethane
  • 2 pints of latex paint.
  • Epoxy - as much as you can obtain. Avoid 5 minute quick setting Epoxy: It leaves you no time to properly set materials.
  • 3/4" wood screws. Any material is fine. Epoxy will cover them.

Layout the Design

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A complex design is unnecessary. If you think about it, a boat is just an overgrown wooden cup, except instead of keeping liquid in, a boat keeps liquid out. The few design considerations were:

  • The maximum width could be no wider than the inside of my Ford Expedition.
  • The maximum length could be no longer than what could be wrapped with a strip of 8-foot plywood. (It came to 7 feet).
  • The bottom had to be as wide as possible for stability.
  • The bottom would be rounded in order to better handle shallow lakes.
  • The shape would be a tear drop and look like a boat.
  • It had to be light enough to carry short distances.

With these parameters set, place an 8x4 plywood panel on the ground and draw a symmetrical teardrop shape. I used the ruler to make sure lines on each side were equidistant to the edges. The process involved trial and error and ended when I was satisfied that the shape looked 'boat-like'.

Cut and Add Beams

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The boat had to be strong enough to keep out 6 cubic feet of water (a cubic foot of water weighs 64 lbs), but light enough to portage short distances. And it had to withstand collisions with branches and rocks. 1x4 beams provided this strength. Cutting these was a matter of guesswork. In order to look boat-like, these were angled so the boat's maximum width would be 4 feet at the top rail (the gunnels) and 3 1/2 feet at the bottom. A jigsaw works fine for these cuts. The beams were spaced on foot apart. This spacing, like many things about this boat, was based on a guess.

Cut and Add the Sides

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With two beams added (maybe there is a more technical term than 'beam'), the sides panels of the boat could be added. To create the sides:

  1. Cut a 4x8 sheet of plywood into two 2x8 peices.
  2. Lay these on top of each other.
  3. Draw out the side. Make the ends curve up slightly. The height should be between 1 and 1 1/2 feet.

With the sides made, screw them to the beams. Be careful to make sure the beams connect to the sides at the same spot. Otherwise, the boat will be asymmetrical. Boat design is very forgiving, with few exceptions. This is one of them. An asymmetrical boat has large cracks to fill and looks bad.

To get the front ends to meet, cut a 2x2 and screw it to the front of one of the plywood panels. Bend both panels until they link up to the 2x2. Make sure they are screwed in. The front, or stem, of the boat is almost ready.

Finally, lift the front of the bottom panel and screw it to the bottom of the 2x2. Sand or saw off any excess wood from the bottom panel.

The most difficult part of the build is complete.

Add the Transom

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The transom is the back of the boat, shaped like a trapezoid. Determine how wide you want the top rear of the boat and draw out the shape in a piece of plywood. Be mindful of symmetry and make sure the height of the part matches the two side panels. Cut the shape out, then cut and screw in 1x4 chords to give it strength.

Complete the Hull Structure

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Right now the sides are not well attached to the bottom and large gaps line the edges of the bottom. Reduce these by cutting small triangles out of 1x4's and place these along the bottom edges half way between the beams. This should reduce these gaps. The smaller the gaps are, the less epoxy is needed later.

This is also a good time to add the mast holder. Cut a 1x4 and place it across the top of the structure, close to the stem. Cut a 1 1/2 inch hole in the center with a jigsaw or (if you have one) a 1 1/4 inch drill bit. This will keep the mast in place. Take another 1x4, cut a similar hole in the center, and place on the bottom panel. Carefully line it up to the top mast holder. If these top and bottom mast holders aren't lined up closely, the eight-foot mast will have an obvious lean.

Create the Gunnels

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Gunnels are the side rail. These add to the structural strength and provide a good place for your hands to grip when boarding, lifting or portaging the boat. To be light, strong and good-looking, take a 4-foot long piece of plywood and trace it along the top of one of the sides. Draw another line four inches parallel to it, then cut. Do this four times:

Along the starboard (right) front. Along the port (left) front.Along the starboard rear.Along the port rear.Make sure there is some overlap between the front and back pieces. You'll have four curvy panels to line along the top of the boat. Use these parts as a template to make two more copies of each panel.

The goal is to create three layers of panels. These three layers are visible in the image, clamped together. When all three are complete, sandwich them together. Glue them together with Epoxy and clamp down. More on Epoxy in the next section.

When both gunnels are complete. Cut a triangle out of 1x4 plywood and place it on top of the stem. This is just for looks.

Epoxy

Epoxy is nasty stuff to work with. It smells terrible, is expensive and is highly toxic. At the same, there is no substitute. Epoxy is the glue and the waterproofing agent to use. Follow the manufacturer's guidelines when using it. Generally this means wearing gloves and being in a well ventilated area. Epoxy is a two-ingredient adhesive: a resin and a hardener. Both have to be mixed prior to use. Quick setting epoxy is available, but 1 hour setting works best for boat building. It allows you time to set and correct whatever you are gluing. Any type of epoxy requires 24 hours of cure time. Clamp tightly any pieces you are gluing, and keep the ambient temperature above 60 degrees Fahrenheit.

Add the Keel and Cover the Stem

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The keel helps keep the boat stable and helps it grip the water and stay strait. Most small sailboats have a deep keel that you sink into the water before setting sail. Usually the setup is complex. I've built two boat that don't have one, and I haven't found a need for a deep, removable keel. This boat uses five strips of plywood. Cut five 1-inch-wide strips of plywood and place them along he bottom center of the boat. Screw them and glue them together. Cut off any excess wood that sticks out in front of the stem. Just that simple. No special detachable keel needed.

The stem has an unsightly crack where the front of the side panels meet. Cover this with a piece of tag board. Yep, paper. Everything will be water proofed, so paper works fine.

Sand, Waterproof and Paint.

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This is the time to add epoxy. Add it to any joint where one piece of wood meets another, or any exposed screwhead. Even if that joint will never get wet, the boat benefits from the strength of the adhesive. If there is any leak, water will find it. Take time to add 2-3 coats over every crack. Some boat builders recommend making a mix of epoxy and sawdust, then covering the glued joint with tape. I've never found that necessary. A thin bead of epoxy, a quarter inch thick at most, is all that is necessary. Adding this in tiny layers helps guarantee that no leaks remain. Make sure a tarp is below the boat, because some epoxy may leak. Also wait 24 hours between each coating, to allow the glue to dry. Finally, keep the temperature above 60 degrees Fahrenheit.

After the layers are applied, fill the bottom of the boat with water. This will instantly alert you of any leaks.

Next, sand every surface until it looks nice. When sanding blobs of epoxy, wear a face mask, respirator, or at least do it outside. Epoxy is toxic.

Then paint. Inexpensive latex works fine. I prefer dark colors because it hides any errors, uneven cuts, etc. It may be necessary to tip or flip the boat, wait a half day for the paint to dry, then paint another side.

When the boat is painted - spray every surface with 3-5 layers of Spar Urethane. Allow it to dry in between coats. Spar Urethane alone does not seal leaks. That's the Epoxy's job. What it does is protect the wood and paint from water damage. When using the boat for paddling and fishing, all parts are likely to get the occasional splash.

Add the Deck

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I don't trust quarter inch plywood to hold my weight. A removable deck of 1x4's allows the boat beams to bear this burden. The deck is removable in order to make the boat easier to carry. To create the deck, determine how long it and wide it can be by measuring the inside of the hull. Make sure it doesn't cover the lower mast holder. Space the 1x4's a half-inch apart and link them with two 1x2's (cut a 1x4 into a 1x2 if needed). The 1x2's should be placed somewhere so that they interlock with the hull beams, which prevents the deck from sliding around.

Build the Oars, Mast and Sail

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Each oar is a 2x2 chord of pine. Cut the corners with a jigsaw and sand it down until the wood is rounded. Closet hangers also work, require no cutting and sanding, but are five times as expensive. Cut a notch into one end of the wood. This is where the paddles will go. The paddles are made of half-inch plywood panels. Glue the paddles and oars together with epoxy. Screw them together for added strength. Spray each oar and paddle with 2-3 coatings of Spar Urethane.

The mast is an eight-foot 2x2. Cut 2 holes in the top: Rope will go here. After cutting and sanding the mast until it looks round, put it into the mast holder to make sure it fits. Just above the mast holder, drill another hole. The spar will attach here.

The spar is a 6-foot 1x2 (or cut 1x4). Drill one hole at the end where it meets the mast. Drill a hole in the enter, and drill two holes toward the end.

The sail is just a bed sheet. Cut it into a triangle. If the cut is jagged, white duct tape helps cover it up.

Rudder and Rigging

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Sailing on Lake Altoona in a DIY boat
Sailing Lake Altoona

The rudder is cut from a 12x1 pine chord and made to look like a rudder. It is detachable and hooks on to two loops that come out of the transom. It is controlled with two ropes that come out of the rudder and move through a series of hooks along the gunnels. The ends of the ropes meet near the mast. The rudder turns by tugging one of the ropes.

The oar locks are each a 2" wide loop of rope screwed into the gunnels.

Rigging is complex, so I'll let the pictures and videos describe it. The benefit of the Bermuda setup is that it has few moving parts and is the easiest to sail. It has been a process of trial and error and I'm still figuring out the best system.

Enjoy!

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Building and sailing your own boat is a hobby that challenges you physically and mentally. At the same time, anybody who has the desire can get into it. When building or sailing, stay safe and follow usual precautions like wearing a life jacket. Have fun out there.