A longbow is not at all difficult to make, requiring only a length of wood, string and a sharp knife. For hundreds of years longbows have been made around the world, and using the same hand-carved process they're still being created. While you could build a longbow using modern power tools, carving them by hand gives you more control over the process, and if you're a beginner, hand-carving allows you to catch mistakes early on. It also lets you experience a building tradition that has won wars, fed families and garnered the longbow a well-earned place in history.
Selecting the wood for your longbow is vital to your carving success. Look for a board that's 6 feet in length; 1 inch by 2 inch boards will provide you with an area that's large enough to carve without being unwieldy. Choose a hardwood for your bow material. Osage and yew are the best woods to work with, though if you're a beginner you would do better with oak or lemonwood, as they are easier to carve and tend to grow straighter giving you less twists in your wood.
Check the grain of your board for suitability. Your wood grain should run straight on the face and sides down the length of the board. The ideal board would have a back that consists of a single layer of wood uninterrupted by any growth rings. You can find wood at your local lumberyard, but for the best wood, try an archery store.
The wood you choose should be aged. A bow made with green wood is more likely to break with use as it ages.
When you've found your perfect board, draw the shape of your bow onto the wood. Follow the grain of your board when possible, working around any knots in the wood, tapering the bow from the center to the tip. When drawn, create a rough shape of your bow using a draw-knife, roughing out only the sides and leaving the back of the board intact.
A tillering board is a board containing a labeled grid from which you suspend your bow horizontally while pulling a string attached to your bow. You can look at the tillering board and compare the pull on each side of the bow to determine if your bow is pulling evenly. Grids should be 1 square inch in size and labeled from the center outward using so you can easily compare equal positions on each side of the bow to determine the nature of the pull.
Work slowly when removing material to form the shape of your bow and make frequent use of the tillering board. Begin carving with the belly of the bow, working outward to the tips. When placed on the tiller, if the bow is pulling unevenly you should adjust the bow's shape by carving more material from the side which pulls least to provide proper balance.
After you've finished carving and balancing your bow, carve the string notches into the ends. Notches should be diagonal and not too deeply cut into the end of the wood. Each notch should be cut 1/8 of an inch into the end of the wood and angled from the center of the notch to the front and rear. Use a rounded file to smooth them out for the string.
Finish the bow by applying several coats of tung oil to protect it from the elements, and then string it for use.