Make a door harp
Provide a musical welcome for you and your guests.
There seems to be some debate about where door harps originated: some sources say China, some say Sweden and some say Finland. Nonetheless, the lore surrounding the door harp’s purpose is consistent. In addition to welcoming visitors, the door harp supposedly draws positive energy in and sends negative energy out. The beauty of this project is that you can use hand tools, woodworking machines or a combination of the two, depending on your skills and interests.
A door harp can be any shape. I create designs by cutting shapes from paper. The size of the harp is often determined by the stock I have on hand. This harp is 11″ high and 8″ wide. The harp should be 1″ to 1-1/2″ thick when completed in order to securely hold the tuning pins. Once you’ve decided on the shape, you’ll need to cut two pieces – a thicker piece for the front and a thinner piece, usually about 1/8″, for the back. The back can be made from Baltic birch ply, or you can use a bandsaw to obtain 1/8″ stock. I use a scroll saw to cut the initial shape but a bandsaw or a coping saw would also do the job.
Next, drill out the sound chamber using the largest Forstner bit you have. I used a 3″ bit. Work from the back of the thicker piece taking care to use the slowest speed on the drill press. Do not drill all the way through. Set the depth stop so the center spur barely cuts through the front face. Using the same center point, turn the blank over and drill a smaller hole from the face side. Choose the size of this sound hole to suit the design of your harp. Place a block of scrap wood in the sound chamber to reduce tear-out as you drill. Once the sound chamber and sound hole are complete glue the face and back together. Once the glue is dry, use a router or spindle sander to flush up the top and bottom, then round over the front edge on the router table or with your block plane and rasp. Find the balance point for the harp and drill a hole in the back that angles upward. This hole fits over a screw driven into the door.
The Sound Chamber
Once the harp has been cut to shape, drill out the sound chamber from the back side. Drill just far enough that the center spur slightly protrudes through to the front. Next, flip the harp over and drill the smaller sound hole, centred on the point where the spur came through.
Ease the Edges
Using a router table equipped with a 1/4" round-over bit, ease the front edge of the door harp. You could also use some hand tools for this small task.
Add a Back
Once the two holes are drilled, adhere a thin plywood or solid back panel to the back of the harp.
Install the Tuning Pins
The pins are installed into 3/16" holes in the face of the harp. Using a special tuning wrench makes the job much easier.
Threading a Hammer
Drill a small hole into the dowel, put the thread into the hole, add some glue then tap a round toothpick into the hole. Once the glue is dry, cut the protruding section of toothpick off. The same process fixes the other end of the string to the hanger.
The hanger needs to be long enough so that the hammers don’t hit each other when the door moves. Any contrasting wood will do. Cut it to a pleasing shape and glue the hanger to the face of the harp. When the glue is dry, apply several coats of your favourite finish. It’s much easier to finish it now before you install the hammers and strings.
Make a dowel section for the hammers either on the lathe or with a block plane, then cut it into lengths for the hammers and drill a 1/16″ hole in the center of each one. Put a piece of thread into the hole and secure it with a round toothpick rolled in wood glue. Snip the toothpick off close to the surface and mushroom the end. Drill holes in the hanger to accept the other end of the thread.
Putting the strings on requires some specialized hardware. Zither tuning pins and piano wire are available from music supply stores. If you discover other sources, please let me know. I’d also recommend purchasing the tuning wrench. It will save time and frustration while installing the pins and tuning the harp. Drill 3/16″ holes, then install the pins. Cut the strings over-long so that there are at least three turns to anchor the string before you start tuning. Now you’re ready to attach the hammers to the hanger. Hang the harp on the wall then use a needle to insert the first thread into the holes in the hanger. Adjust the length of each thread so that the middle of the hammer hits the middle of the string. This way the hammer will hit only one string. Secure the thread with a toothpick and glue. Repeat for the other hammers.
Install the strings and tune them so they sound good to you. After a couple of days the pitch will sag as the strings stretch so you’ll have to adjust the tuning. Enjoy the results of your work each time someone comes through the door.