Toy boats are loads of fun! This one looks like a hydroplane with a bullfrog aboard, and it’s an ideal project to make with the kids. All it takes to power is a balloon and a little huff and puff, and away it goes!
Gather your supplies
Hull 60 x 20 x 220mm balsa
Sponsons (2) 37 x 20 x 120mm balsa
Tails (2) 35 x 9.5 x 75mm balsa
Balloon block 37 x 20 x 35mm balsa
Wing 40 x 9.5 x 82mm balsa
Windshield 12 x 12 x 68mm balsa
Material quantities are small unless you make several boats. As balsa is so soft and easy to shape with a knife, you can make all parts from short lengths of 100 x 20mm and 40 x 9.5mm material.
- Step 1: Using coarse and then fine sandpaper on a cork block, shape hull by rounding front and streamlining the underside.
- Step 2: Cut a 45° angle at back of each sponson, to make a left and a right-hand sponson. Shape fronts to curve upwards into points.
- Step 3: Glue, predrill and nail sponsons to hull sides so they are protruding from front by about 20mm and tops are flush.
- Step 4: Cut tops of tails so they slope down by 8mm at front, and front edges so they slope back by 12mm at the top. Glue and nail tails to balloon block. Sand front edge of block so it is flush with front slope of tails. Shape front of wing to create an angle, then glue to tail tops. When dry, glue and nail to back end of hull (as shown).
- Step 5: Sand front edge of windshield to create an angle of about 45Â°. Glue and nail in place across the hull.
- Step 6: Cut a vertical slit in centre of rear underside of hull, then cut a small plastic rudder from nail packaging. Test to fit, then remove.
- Step 7: With boat upside down, use a succession of drill bits (3, 6, 9 and 12mm) to bore an angled hole through balloon block. When boat is upright, the hole should slope down towards back of boat.
- Step 8: Sand whole boat smooth. Paint with undercoat, then 2 coats of gloss enamel. Allow to dry. Add super-speedy stickers (optional).
- Step 9: Cut plastic tube to length of hole. Feed neck of balloon through tube until opening is on other side. Push tube with balloon through hole of balloon block. Replace rudder and you’re ready to race. Place on water, blow up balloon, then let the boat go.
You’ll also need
20mm and 40mm fine nails; small piece of plastic (cut from nail packaging); PVA glue; 35mm offcut of 12mm plastic tube; sealer/undercoat; gloss enamel paint of choice; balloon; stickers (optional)