In the Studio: The Harp Tool

A few summers ago I was at a wood-fire residency at Watershed Center for the Ceramic Arts. While there, I came across a tool that I had never seen before. The unique design and many uses of this harp tool grabbed my attention and stuck with me. When I arrived home, I decided to make one for myself. So, I gathered supplies at the hardware store and began experimenting. Since then, I have made several versions.

I use this tool to cut slabs from commercial clay fresh out of the bag (A), to cut even slabs using slab sticks (B), as well as for sculpting and faceting. The harp tool can be adapted to many uses.

Tools (C):

• Small hand saw              • Set of drill bits

• Hammer                          • Sharp utility knife or an X-Acto knife

• Needle-nose pliers        • Ruler

• Screwdriver                    • Drill

• Small square                  • Drill-bit gauge

Materials (C):

• Oak dowels: 1 at ¾×36 inches, 1 at 5⁄8×36 inches

• Guitar string (old or new)

• Thin rope (approximately 10 feet)

• #6¾-inch brass wood screws

A Dividing a block of clay up into smaller sections.

B Cutting a 1⁄8-inch slab of clay using the harp tool and slab sticks.

C The tools and materials you will need to create a harp tool.

 

Step by Step

First, use the small saw to cut the dowels down to length. Start with the ¾-inch oak dowel, and cut this down into two 10½-inch rods. Next, take the 5⁄8-inch oak dowel and cut into two pieces, one to 9¾ inches in length, and another to 5 inches in length.

After the dowels are cut, take the two 10½-inch long, ¾-inch-diameter dowels and measure 4¼-inches down from one end. Once marked, use a small drill bit (approximately ³16) to drill a pilot hole through the dowel (1). Note: It’s important to make sure that your hole is centered in the dowel and not off to one side. Now, repeat with the ³⁄8-inch bit, using the smaller hole as a guide (2).

Take the 58×9¾-inch cross-support dowel. We will be cutting down both ends so that they fit into the holes drilled into the 10½-inch dowels. Mark ¾-inch at each end and make a line around the entire circumference. Then take the drill gauge and draw a 3⁄8-inch circle on both flat ends of the dowel. This will help you keep track of how much wood to cut off and give you a better fit.

1 Drill out the ³⁄8-inch holes for the cross support to be inserted into.

2 The ³⁄8-inch holes drilled into the vertical arms for the cross support.

3 Cut the cross support ends down to ³⁄8 inch to fit into the drilled holes.

 

Next, carve down the ends of the dowel to fit. Carefully using the box cutter or X-Acto knife, begin to cut along the line and cut away the extra material (3). When you think you’re getting close to size, stop and test the fit of this dowel into the longer dowel (4). Once your dowels fit together tightly, use some sandpaper to smooth out any rough edges. Note: Don’t make these joints too tight. Due to the tension you will place on them, it’s best to have a little flex; this can be achieved with the use of sandpaper.

Notch the top of the long dowels to create a groove for the tensioned nylon to rest in. First, secure the two dowels together. Use the 3⁄8-inch drill bit, and slide into the existing holes for the cross support that you already drilled. Using the nylon rope, tie the pieces together. This will hold the two dowels in place while you drill, ensuring the notches are in the same place on each rod (5). Mark approximately ¾ inch below the top and drill between the two dowels to create a half circle in each. Remove the rope and drill bit, holding the two dowel rods together. Use sandpaper to smooth away any rough edges.

Mark and score a small notch for the guitar string to rest in at the bottom of the long dowels to ensure the string stays in place during use (6). The notch needs to be about the thickness of the guitar string. You can use either your X-Acto knife or the box cutter to create a small slit on the bottom of your long dowels that runs parallel to the cross-support dowel that holds the two together.

4 Insert the cross support into the sides and check with a square to ensure a perfect 90° angle.

5 Create a notch in the two vertical sides for the tension rope to rest in using the ³⁄8-inch drill bit.

6 Carve a small groove into the end of the long dowels for the tensioned guitar string to rest in using an X-Acto knife.

 

To attach the guitar string, use a small nail or drill bit to start a hole 2 inches up from the bottom of the dowels. Once the pilot holes are set, place a small amount of wax on the threads of the screws, this allows them to glide in easier—beeswax, candle wax, or paste wax all work well. Screw them in until they’re approximately 18 inch out. Take the guitar string and wrap it around the screw heads getting the string snug (7), then finish screwing them in. I use a small amount of tape to secure the ends of the string (see 9).

Now to tension the string, cut approximately 48 inches of nylon rope and tie the ends together with an overhand knot. Double up the rope and place each of the two ends over the grooves in the top of the dowels. Insert the 5-inch dowel into the center of the rope and use the dowel to twist the rope until there’s tension on the guitar string (8). The 5-inch dowel will keep tension against the center dowel and can be adjusted as needed.

7 Wrap the wire around the brass screw and back around its self to ensure the wire stays tight.

8 Insert the shorter wooden dowel into the middle of the tensioning rope and rotating the dowel to create tension.

9 The finished product, with wire ends taped off and the tensioning dowel rotated, creating a multi-use tool that is ready for use.

 

I hope you enjoy making and using the harp tool as much as I do (9)!

Brice Dyer is a ceramic artist living in Denver Colorado, his work is influenced by geology and is primarily handbuilt and functional.

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