Building a boat out of plywood can be a very neat project to take on. There will be a few things to decide on before building a plywood boat. The size of the boat and the shape will be important factors when deciding. There are plans available for different styles of plywood boats. After picking out the plan or going with your own design you will want to make sure you own or have access to the tools you will need. Table saws or skill saws work great for cutting plywood to the right lengths. A jig saw may be needed for cutting holes or curves in the plywood. A good drill and some drill bits and a driver for the drill will make easy work of wood screws.
Materials should be gathered before starting the project as well. Plywood, wood glue, screws and a lot of sand paper in different grits. You will also need a fiberglass kit that has enough material to cover the bottom and sides of the boat. This is how you will make the boat water tight. If you are going to try and make a V bottom boat you will need the thinnest plywood you can find. The ply wood for the V bottom will need to be able to bend enough to achieve the right contour on the sides of the boat. Quarter inch thick plywood will work nicely. If you are going to make a flat bottom john boat you will be able to use a thicker plywood. This will be the faster and easier of the two styles to build.
After cutting the pieces out for the flat bottom boat start putting them together using lots of glue and screws. Make braces along the interior of the boat trying not to make the boat to heavy. After the boat takes its shape and the exterior is finished sand the plywood down leaving the surface rough. Start applying the fiber glass resin and material in small workable sections until the exterior of the boat is covered and you are confident the boats exterior is water tight. After the fiberglass has cured you can sand it smooth and prepare it for primer and paint. Priming and painting should be done with marine grade products and can be applied with a brush if you would like.
For the V bottom boat you will want to build the frame first using the jig saw to cut the contour of the boats side. Start bending the plywood onto the frame pieces. Attach the plywood with screws and plenty of wood glue. Leave a seam down the center of the boat because if you try to bend the plywood around the V you will crack it. After completing both sides add a second layer of plywood directly on the first layer using plenty of wood glue between the layers. Sand the plywood and water proof it using the fiberglass kit making sure you fill the center seam of the boat. After the fiber glass is dry enough you can sand it and prepare it for paint and primer. Make sure to use marine grade primer and paint for maximum paint durability.
After the shell of your boat is finished you can concentrate on the inside by adding various accessories witch you may have custom built yourself. Try not to make your boat to heavy from the beginning because you will need to put your fishing or hunting supplies in it also.