The Celtic harp or folk harp, with its characteristic bow-shape and often smaller size, is a popular style of harp for beginners, and the relatively simple style of construction makes it an easier instrument to build than the classical pedal harp. Although the Celtic harp has become second in popularity to the pedal harp, the art of its construction has had a recent resurgence of popularity, making it feasible for at-home construction.
Design your harp or purchase design plans. The arch of the neck or harmonic curve, which is more than just aesthetically pleasing, determines the length of the strings and the notes played. When designing your harp, consider what size you want it to be. While a larger size will allow you to install a greater range of strings and play over a greater number of octaves, a smaller harp will be lighter and more easily played.
Purchase your lumber. Although many plans recommend plywood for beginners, most experts recommend a harder wood like maple, walnut or cherry. The wood must be sturdy enough to withstand the pressure that plucked strings will apply to it, so it's important to balance the flexibility of the wood with the resonance of the sound it will produce. Once you've chosen your wood, cut it according to your plans.
Sand your wood smooth and then glue it together according to the plans. Starting with the soundbox, glue the components together and clamp the pieces in place to ensure a tight seal. Glue the harmonic curve and the pillar of the harp together and after the soundbox is complete, glue this balanced curve and pillar to the soundbox to form a triangular shape. Attach the legs last, so you can be sure the completed harp will stand evenly on all four legs. Use a strong glue. Plucking the strings applies intense pressure to the instrument, and if it's not tightly held together, the harp will collapse.
Stain, varnish or paint your harp. If you like, you can add decoration to the pillar and the sides of the sound box. This is your chance to personalise the harp, so decorate it however you see fit.
Drill the holes for the strings in the neck and the soundboard. The holes must be precisely lined up between the neck and the soundboard, and they must be evenly spaced. Take care with this stage because the strings will determine the sound of your harp.
Choose your strings and string your harp. Nylon strings are most common, but gut and metal strings also can be used. Gut strings offer a more mellow sound, while metal strings give louder and longer tones. String your harp from the bottom up and insert the tuning pins into the harmonic curve. Use a tuning lever to ensure that the strings are correctly tuned as you tie them.
Don't hesitate to seek help from a trained woodworker or harpist if at any point you struggle to construct your harp.
Wear a face mask and goggles when sanding and varnishing your harp because the dust and fumes can be harmful.