Shell Repairs

The shell of your Djembe, Ashiko, djun-djun, or any other hand drum is the most important piece of having a successful sound. The shell is the foundation, and without a strong foundation, you'll be frustrated with the sound, and replacing the head will only frustrate you more. If you feel your shell might need some work, I'm providing some tips to get you going in the right direction.

The most obvious cause of a shell not sounding up to it's potential is on a shell that is carved quick for production rather than for quality. The bearing edge is often left in very poor shape on these drums. The bearing edge is extremely important to the sound of your drum, the life of your head, and the well being of your hands. Skimping on this is a bad idea. If your head is off anyway, take a good look at your bearing edge and determine if it could use some TLC.

You want the bearing edge to be level, smooth, even, and consistent. Also make sure that the edge makes the djembe as round as possible. Even with a slightly out of round djembe, you can achieve a uniform circumference by adjust the bearing edge, however it's always best if your drum is true to begin with. The fist thing you'll want to look at is the levelness of the head. Get eye level with the bearing edge and look over top of the shell to see any dips or high points in the top of the shell, it should be perfectly flat (note that the bearing edge should not be flat per say, I use the term to reference the levelness of the top of the shell). If it's not level you can use a hand plane, rasps, and sand paper to make it flat and level. A good test is to put the top of the djembe on a flat, level surface and shine a flashlight in it from the base of the drum. Turn the lights off and if you can see light coming from under the shell you might need to work it a bit more. If the drum rocks you definitely need to work the edge some. Mark any high points and file them down with the rasp until they are level with the rest of the shell. If you have a hand plane (electric or not) you can simplify the process of using the rasps. Take it at small increments and keep the plane level on the surface until you have a nice even and level surface. Be VERY careful if you decide to go with an electric hand plane, you can chip out too much wood and really damage the shell; I always suggest using a non electric or keeping it to rasps and sand paper.

Once your bearing edge is level, you'll need to reshape the curve of the edge. This curve helps determine the sound, sustain, and the bruises on your hands. The sharper this curve is, the less skin touches the shell and the more it vibrates. This is great if you like a long sustain, but really does a beating on your hands. I prefer a short crisp sound, and it just so happens that this calls for a very rounded bearing edge with more surface area for your hands to hit. As a general rule, look at your thumb profile. Your nail will be the inside edge of the shell, your thumb slope will be the outside edge of the shell. This is a good place to start in getting an idea of what the shape should look like. Round over the outside edge good with rasps and sandpaper until it looks like your thumb profile. Make sure you stay consistent and even all around the shell. The inside of the bearing edge should be a much sharper drop off. You don't want it sharp though. See the picture below for a good slope for the bearing edge. Adjusting this will adjust the sound you get; unfortunately it takes a lot of time to adjust the slope and rehead the drum to find if you like the sound or not. The picture below is a good representation of how I do the bearing edge about 95 percent of the time. It seems to get the best sound and be comfortable to play on. When you are done with the shaping, take some 220 grit sand paper and go over the edge, making sure to remove all rasp marks, and just to smooth things out a bit better. If you want to, take it up to 400 grit for a really smooth, slick surface.

Another common problem is shell cracks, usually due to the wood not being completely cured or dry before the carving takes place, but can also develop if you do not treat your drum properly. Look at our djembe care section for more info on how to care for a hand drum if you have any questions about it.

Small cracks that do not penetrate through the shell are usually not a problem. Keep an eye on them to make sure they don't continue to grow. To stop a crack from developing more and to fill it if it has gone all the way through the djembe shell, the following will give you some advice. Once you determine that you need to take action on your shell, you need to have a few tools. A drill, sandpaper, glue (super glue, Cyanoacrylate glue, or a wood filler if the crack is big enough). You first want to stop the crack from growing. If you don't do this, the crack will continue to grow. Find the ends of the crack and drill it out, all the way through the shell. Use a bit that is just slightly larger than the crack, usually a 1/16 or 1/8” bit at the largest. This creates some freedom for the wood to move in the area, which is why its splitting in the first place. Wood constantly absorbs and releases moisture depending on it's environment. A crack develops at a stress point, so release the stress. The next step is to fill the crack. If it's big enough, use wood filler that matches the color of the shell and dries hard (not the furniture filler that stays like a puddy). If the crack isn't too large, sand around the crack to fill it in with sawdust. Then put the glue directly in the crack. The glue should mix with the sawdust to form a very solid mixture that resembles the makeup of the wood. Sand it smooth once it dries and repeat the process if you need to. You might want to do this on both sides of the crack. Once you have repaired the crack and every is dry, you should recoat the shell with oil.

There are plenty of oils that protect your shell well. I like Boiled Linseed Oil (BLO), Danish Oil (which is BLO with some added dryers and varnish to harden it better), Tung Oil, and Coconut Oil.

Of these Coconut Oil is the most natural, but this oil doesn't completely dry, and you will need to recoat ever 6 months or so to keep your shell in good shape. The oil seeps in the wood well and protects it from the elements and it really brings out the natural beauty in wood, but it rubs off easily over time.

BLO is a good option, but again, BLO never completely hardens and can take a while to dry to a point where you can head your djembe. BLO is good if you want to re-oil every time you change your head, which is a good idea anyways. BLO should last 2 years or so before needing to be recoated. It will darken your wood, but seals it nicely from moisture.

Danish oil is pretty much BLO with some added chemicals that help it dry quicker and it hardens more. Danish oil will last much longer than BLO, but has some nasty chemicals and is difficult to remove should you want to try different oil. I use a few coats of Danish oil on my Walnut and Purple Heart drums, but usually stick with something softer like coconut oil or BLO for the imported African hand drums that I deal with.

As with all of my sections, my goal for these pages is to provide accurate information that will be helpful. If you feel I left anything out, or have any specific questions, please write me at info@rhythmhousedrums.com. I'm happy to help.