Bowyers often reinforce a bow's back with a natural material, such as rawhide, sinew or silk, to increase the bow's draw strength and prevent it from breaking when drawn. A backing also allows unique shapes that are impossible in wood without the extra strength of a backing. (See Reference 1, pages 132-138) A bow can be backed with natural material, but it often has flaws. Fiberglass is more consistent and just as strong. Its long history with wood bows proves it can be just as good as natural materials for backing, (See Reference 2, page 67) and it is also quicker to apply.
Remove all finish, such as linseed oil or varnish, from the bow's back with 80-grit sandpaper. A rough wooden surface for the fiberglass to stick to is necessary.
Mix a batch of epoxy in a cup. Start with a small batch, such as a half-cup, because epoxy starts to cure once mixed. It is easier to use a small batch quickly than a large one. If you need more, mix up another batch. All epoxies are different, so follow the instructions for mixing ratios.
Dribble a line of epoxy down the bow's back from tip to tip. Spread it around with a plastic squeegee until you have completely covered the bow's exposed wood.
Place the fiberglass's rough side down on the dribbled epoxy. The fiberglass absorbs any epoxy not soaked up by the wood. Pour more epoxy over the fiberglass and use the squeegee to spread it evenly. Keep adding epoxy until the fiberglass turns from opaque to clear.
Wait 30 minutes for the epoxy to set then squeegee any excess epoxy from the fiberglass. Excess epoxy floats the fiberglass and makes it look glossy. You want a matte, clear appearance.
Stick the bow inside a heat box and cure it according to the epoxy's instructions.
Items you will need
- Unidirectional "E" fiberglass, archery-specific
- Plastic squeegee
- Heat box
- Make a heat box from a wooden crate big enough to hold the bow by lining the crate's top with four heat lamps connected to a thermostat.
- Wear gloves and a respirator when working with epoxy.
- Archer taking aim to hit the bull's eye image by Andris Daugovich from Fotolia.com