Thursday, June 27, 2013

Crafting a Djembe Drum

Copyright 2004 © by Chris Bittner 

My name is Chris Bittner, and I am a drum maker living in central Pennsylvania. As you already know, drumming is fun, it is powerful, and oftentimes spiritual for people. We know that we enjoy the rhythm. But many people are left curious about the drums themselves: what are they made of, and how are they made? I would like to describe my drum making experience, so that you can learn a little about what I do.

Although I have been making drums for just five years, my drum journey really began when I was a child. My brother went around playing rhythms on everything, and since I had to copy him, I did it too. This is something which has never left me. I played "drums" on my dinner table, car dashboard, etc. When I was a child, I also learned to enjoy working with wood. My father taught me to use tools and make small projects. In my early twenties, I began making wood sculptures. Then about ten years ago, I began playing in any drum circle I could find, as well as a local West African drum and dance troupe. In 1999, I combined my love of woodworking with drumming, and began making drums.

I attended a four day drum making workshop offered by Yendor Drums. We began with djembe shells that were rough-carved in Ghana. Through the course, we finish-carved the drum shells, prepared a fresh goatskin, assembled and tuned the drum. Yendor sells all the necessary materials, so I felt that it was time for me to start my own small business making and selling drums.

Most of the drums I have made (close to 100 now) have been made from African drum shells. These drum shells are carved by drum makers in Ghana. The wood they use is called tweneboa. Tweneboa is lighter, softer and less dense than many other African drum woods. It has the advantage of being much easier to carve. I have also made a number of drums from African drum shells made from iroko wood, imported from Ivory Coast. By contrast, iroko wood is very hard and heavy. It is appropriate to note that most African drums (and especially djembes) are made from the harder, heavier woods. Since it is more difficult to make drums from harder wood, I am sure that it is used for good reason. However, many fine drums are also made from the softer Tweneboa wood, so I believe each type has its merits.

A typical drum project will begin when someone contacts me who wants to buy a drum. Together we will decide on the type of drum (djembe is by far most popular, I also have solid shell ashikos) and desired size. I choose an appropriate drum shell and begin work.

Preparing The Shell

Usually, the exterior of the shell will be pretty close to a finished shape. The inside, however, always needs quite a bit of work. There tends to be a lot of extra wood on the inside of the bowl and also inside the pipe (lower part of the djembe). The most useful hand tool for carving this wood out is called a scorp. A scorp is a wood gouge that works on the pull stroke. It is necessary to cut the wood with the grain, which means from the middle of the djembe toward the ends. Cutting the opposite direction with a straight gouge can be done, but it generally is difficult or impossible. Woodcraft (http://www.woodcraft.com/) sells a good scorp. I remove excess wood from the interior until I have a uniform thickness of about 3/4 inch.

I smooth the exterior with a sureform. This is a tool that looks like a cheese grater on the bottom. After that, I use coarse sandpaper (perhaps 80 grit) to start smoothing the surface. Then I use my power sander with finer and finer grits until I am happy with the smoothness.

Perhaps the most important aspect of the woodwork is the shaping of the bearing edge (top edge that will support the skin). There are three aspects to this: making the rim round, rounding the outer edge, and making the rim flat.

I measure the diameter of the top rim, and usually discover that it is not quite exactly round. For example, it may measure 13" in one direction, and 13 1/4" in another. What I do is cut a cardboard circle that is 13" in diameter and as perfectly round as I can make it. I place this circle on top of the drum and center it. A circle is drawn around the edge of the cardboard. Then I can use a sureform to make the outside perfectly round. I do the same for the inside edge of the bearing edge. These steps are not absolutely essential, but I feel that a round drum is more likely to sound really good.

Next, I use a woodrasp to bevel the outside of the bearing edge. The outside should be nicely rounded so that your hand will not hit a sharp corner as you play the drum. It also will allow the skin to slide smoothly over the edge when the skin is attached or tuned. Do not round the inside edge at this point. Allow the inside edge to be a little pointy, and the highest point on the edge. At this point, I will lay a sheet of glass down on top of the drum. I look under the glass, and can see where I need to remove some wood using a rasp to make the top rim flat. When it gets pretty close, I use a sanding board to make the top perfectly flat. The sanding board is simply a nice, flat piece of plywood, about 18" square (you could also use glass or steel plate), with adhesive backed 60 grit sandpaper stuck on it. Lay the board down on top of the drum and slide it around in a circular motion. You will soon see that you have created a flat area along the inside top edge of the drum. Stop the sanding when the flat area appears on the entire circle.

At this point, I use the rasp, cutting in a motion from the outside of the rim toward the inside, taking care to keep the front of the rasp a little higher than the rear, with respect to the flat plane of the top edge. In other words, your final result must be that the inside of the rim should be the highest point of the rim, with the rest of your flat area having been worked down into the outside curve. The danger is that the drum may wind up with a "buzz" if there is any flat area left on the top rim.

I like to use the sanding board on the bottom rim of the drum, too. Shape it however you like.

The wood should be sealed with some type of finish. Many people will seal the drum inside and out, but I usually only finish the outside. If the wood has been properly seasoned, I would expect no further problems with cracking. Many types of wood finish are available, and I think any type you like is acceptable. I generally use boiled linseed oil, or danish oil finish, and sometimes polyurethane if I want a really durable finish.

Attaching The Skin

Now the drum shell is ready. Three steel rings are needed to secure the skin. Two of them will hold the skin at the top of the drum, one will act as a counter hoop at the drum's middle. For djembes, the lower ring must either be big enough to go over the bottom of the drum (which often makes it ride unacceptably high on the bowl), or it must be wrapped around the middle of the drum and welded there. The latter is what I usually do. I use 1/4 inch round steel rod bent into a circle. For the top rings, you might want to order the rings from a drummaker or supplier, or have you local sheet metal or welding shop make the rings for you. Make sure they are solidly welded, as insufficient welds can break under the drum's tension.

Each average size djembe needs about 85 to 100 feet of rope. Use good rope! I suggest rope that is 3/16" to 1/4" in thickness. You want rope that is as non-stretch as possible, usually called static line in climbing supply shops. Most drum maker suppliers will offer good rope.

The uppermost and lower ring will be wrapped with the cradle loops of the Mali weave. The longer vertical rope will connect the two rings. Goatskin is the best type of skin for djembes. It is the perfect thickness to produce the wide range of tones that make the djembe so popular. Ashikos may be headed with goat, deer, elk, or even cowskin. Thicker skin will give deeper, more mellow ranges of tones. My ashikos with cowskin sound very conga-like.

I like to dehair my skins before I apply them to the drum. I feel that it is easier, and makes a cleaner looking finished drum. It is more traditional, however, to put the skin on the drum with the hair still on, then scrape the hair off of the playing surface. I dehair hides by placing them into a barrel of water with perhaps two dry quarts of hydrated garden lime. Over several days to two weeks, the hair will come loose and be very easy to scrape off, leaving a nice smooth skin. Bear in mind that the lime is somewhat caustic, so it is best to wear gloves and eye goggles. Others have said that wood ashes will also work the same way. Skins can be used fresh, but most of us get our skins in dry form by mail order. I will put a dry goatskin in a barrel of clear water and let it soak overnight. In the morning, I am ready to skin the drum.

The bearing edge should be rubbed with parafin prior to applying the skin. This seals the wood somewhat from the moisture in the skin, and allows the skin to move smoothly over the edge.

I lay the skin on a table, hair side up, and lay the third ring (the one without ropes on it) on top of the skin, centering it on the spineline of the skin. The edges of the skin are folded up and into the center of the ring. The top ring, with its cradle rope attached, is laid on top of the skin. This assemblage is then set on top of the drum, centered as well as possible. The long rope is then laced up and down between the upper and lower rings, until it is laced all the way around. I slowly tighten the rope taking care to keep the top rings even with the top rim. When I can tighten no more by hand, I use a leverage bar to continue slowly tightening the rope. When it becomes very tight, I hold the tension with vise grips and set the drum aside to dry for a few days. After it is dry, it can be tuned some more until it sounds great. A drum is born!

Carving Shells

Another aspect to my drum making is the carving of drum shells from logs. I have been able to get log sections from numerous sources, usually when trees are taken down for some reason. The tree cutting guys are usually happy to give me the log sections, since they would otherwise have to haul it away. And so I have gotten pieces of elm, maple, walnut, cherry, ash, and perhaps a couple others. I have taught myself to use a chainsaw and other power tools to carve drum shells. Needless to say, this can be very dangerous work, so please be careful and work within your skills. I begin by using the chainsaw to cut the ends of the log off straight. Then I use an angle grinder with a chainsaw-tooth attachment to slowly carve out the inside of the bowl (for a djembe). I use the chainsaw to do a plunge cut straight up through the bottom to meet the bowl. Another plunge cut perpendicular to the first makes an "X" shaped hole. Then it is possible to use a large gouge and hammer to knock chunks out to form the inside of the pipe. I use the chainsaw and angle grinder to slowly carve away wood from to outside of the drum, doing my best to keep the drum symmetrical. Five hours and a sore back later, I have a rough carved drum shell!

Now comes the important part. Since the wood is green, it still has a lot of moisture in it. It is essential to season (dry) the wood slowly so that it doesn't crack in the process. This is not an easy task. Here's what I do. I melt some paraffin and paint it onto the top and bottom rims of the shell. I use a small propane torch to drive the paraffin into the rims, ensuring that the wood is sealed. The rims are where the endgrain of the wood is. Moisture will evaporate from the endgrain ten times faster than from the sides. When wood dries, it shrinks. If one area shrinks faster than another, cracks develop. Therefore it is important to seal the wood and slow the drying where it dries the fastest, the endgrain. Now the shell must be stored and allowed to dry for some time. Complete drying generally takes from six to twelve months. You can track the drying by weighing the drum shell monthly. It will lose weight as it dries. When it stops losing weight, it is duly seasoned.

Where you store the drum is very important. The idea is that the wood must dry slowly and naturally. Therefore, you do not want to store it in a heated indoor space, because the air is dry and would dry the wood too rapidly. Air conditioning is equally undesirable. The best place would be a garage or other unheated space, that does not get too hot if you are doing this in the summer. Cold weather does not seem to be detrimental in my experience. Make sure the shell is not in any wind. Make sure it is out of the sun. Choose the most ideal space you can find, even if you have to take it to uncle Fred's shed.

Some drum shells will crack in the drying process no matter how careful you are. Cracked shells can be filled with epoxy mixed with sawdust to repair the crack. It won't look pretty, but you can still use the shell. I hope you have enjoyed this essay on my experiences with drummaking. Feel free to contact me if you have any questions, I am happy to share. 

Chris Bittner developed an appreciation of wood at an early age, as well as a talent for working with it. Later in life he learned the joys of rhythm and community drumming. In 1999, Chris made his first djembe, when it became magically apparent to him that drum making could be his full time endeavor. And so, DrumWorks was born, in an effort to work at what he loves, and to provide people with the instruments so that they could enjoy rhythm as much as he does. You may learn more about Chris and DrumWorks at http://www.skillpages.com/drummer/akron-united-states/chris.bittner.

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