Building a boat from scratch will help a child understand the basic mechanics of how a ship floats and how it is propelled through the water. A child may wonder what a keel is good for. Through the building process, she will realise that without the keel the ship will capsize. A younger child may enjoy making a ship from a shoebox.
Draw the outline of the boat on the block of balsa wood. Remember the boat should be pointed in the front and flat on the back.
Chip away the wood around the outline, using the carving knife. Remember to taper the sides to make a rounded bottom for the boat.
Hollow out the hull to about a 6 mm (1/4 inch) thickness around the sides and a 1.8 cm (3/4 inch) thickness along the bottom.
Carve a 9.5 cm (3 3/4 inch) groove along the bottom of the boat, front to back. Make the groove 6 mm (1/4 inch) deep.
Cut a 4.5 cm (1 3/4 inch) by 9.5 cm (3 3/4 inch) rectangle from the sheet of balsa. This will serve as the ship's keel.
Make a diagonal cut along one side of the rectangle (the 4.5 cm side, NOT the 9.5 cm side). The result will be a pointed tip on the keel which will face forward when attached to the hull.
Glue the fishing weights to the bottom of the keel.
Coat the top of the keel with glue and slide the keel into the groove on the bottom of the hull.
Drill a 5 mm (3/16 inch) diameter hole inside the hull. Make the hole 6 mm (1/4 inch) deep and 6.4 cm (2 1/2 inches) from the bow.
Cut a 18.4 cm (7 1/4 inch) mast from the wooden dowel.
Cut a 6 mm (1/4 inch) by 14 cm (5 1/2 inch) strip from the balsa sheet. This will be the boom.
Glue the boom at a right angle to the mast. Place it 2.5 cm (1 inch) from the bottom.
Cut a triangular sail that measures 14 cm (5 1/2 inch) wide and 16.5 cm (6 1/2 inch) tall, from the nylon cloth.
Sand and decorate the boat parts before gluing the sail and mast in place.
Place a few drops of glue in the drilled hole; then insert the mast.
Spray the entire boat and sail with silicone sealant.
Cut out portholes on both sides of the shoebox. Start in the centre of each side and work your way out.
Secure the cover on the shoebox with tape.
Make smoke stacks for the boat by rolling a sheet of coloured paper about 10 cm (4 inches) long. Tape the rolls to keep their shape. Make two or three smoke stacks.
Cut small slits in the bases of the smoke stacks. You will need to make three or four slits. Fold the tabs formed by the slits outward and tape them to the top of the shoebox cover.
Decorate the boat with paint, stickers or coloured markers.
Be very careful when cutting and shaping the balsa wood. It is a very soft material and can be easily split. For fun decorate the inside of the shoebox boat with people that you can see through the portholes.
The carving and cutting of the boat should be done by an older child under the supervision of an adult, or by the adult.