One way to improve the appearance of a go-kart is to construct a fibreglass body shell. It is possible to make a fibreglass body for a go-kart that will give it the appearance of a sports car, race car, pickup truck, stock vehicle or an outlandish design such as a flying saucer.
Draw a shape representing the side view of the go-kart body on a large piece of paper. Draw a shape representing the front view of the go-kart on a piece of paper. Repeat this procedure for the rear view of the go-kart. Cut the paper along the drawn lines. The cutouts will serve as guides for cutting the plywood used to construct the mould.
Lay the side view guide on top of a sheet of 3/8-inch plywood. Mark around the side view guide. Cut the plywood along the marks. This will provide one side of the go-kart mould. Repeat this procedure with another sheet of plywood to make the other side of the mould.
Lay the front view guide on top of a sheet of 3/8-inch plywood. Mark around the front view guide. Cut the plywood along the marks. This piece of plywood will serve as the front of the mould. Lay the rear view guide on top of a sheet of 3/8-inch plywood. Mark around the rear view guide. Cut the plywood along the marks. The rear of the mould will be made from this piece.
Assemble the cut plywood using glue and wood screws. This will create a mould that is open at the top and bottom. Measure and cut more plywood to fill some of these spaces, remembering to leave room for the driver. Glue the plywood pieces to the top of the mould. Leave the bottom of the mould open.
Apply drywall compound to all corners in the interior of the mould. Wait for it to set, according to the manufacturer's instructions. Apply a layer of drywall compound to every surface in the interior of the mould. Wait for the drywall compound to set. Sand the drywall compound thoroughly. Any imperfections in the drywall compound will be mirrored in the go-kart body.
Coat the inside of the mould with car buffing wax. The drywall compound will soak up the wax, so several coats of wax will be needed. Make sure that the entire surface has been waxed before proceeding. Any exposed drywall compound will make it difficult to remove the fibreglass from the mould.
Apply a layer of fibreglass cloth and resin to the interior of the mould. The cloth should protrude from the edge of the mould by at least 1 inch. This will provide a surface to grip when freeing the fibreglass from the mould. Smooth the fibreglass out with a hard plastic roller to remove any air bubbles. Apply another layer of fibreglass and resin to the inside of the mould. Use the plastic roller to smooth out any air bubbles. Apply a third layer of fibreglass and resin, again smoothing out any air bubbles with the hard plastic roller. Allow the fibreglass and resin to dry according to the manufacturer's specifications.
Grip the protruding fibreglass firmly. Pull the fibreglass away from the mould. Examine the fibreglass for defects or imperfections. Fill these with more fibreglass and resin. Wait for these areas to dry. Sand the entire body with very fine sandpaper.