Building a Hang Drum
Other Projects:
A few months back I stumbled across a video blog by a moderately well known musician. I watched for a few minutes as this person talked about a new album before picking up a very interesting instrument. It appeared to be some sort of steel drum in the shape of a UFO. Unsure of what to expect, I kept watching and was blown away by the sweet percussive tones coming from this strange instrument. It was played with the hands, which just made it seem all the more exotic.

I forgot about this video until about a month ago when I came across another video: YouTube Video

Now I knew what this instrument was called, a Hang. Through much research I learned all I could about them. They are obscenely expensive, and imitation drums using tuned tounges just don't have the same feel about them. My only choice was to build one.

Unable to find the slightest shred of information regarding the process by which Hang drums are made, I turned to researching traditional steel pan making techniques. I found an excellent book made available for free online that I used as a resource throughout my building process: Steel Pan Tuning

I changed many of the techniques to suit what would be required for a Hang. Since this was my first attempt at making any sort of steel pan, I did not focus on achieving the exact asthetics of a Hang, but instead worked at creating the tones through a standard steel pan note shape. Here is the result of my work, notice I have not yet made the resonator half:
As is done when building a traditional steel pan, I started with the bottom of a 55 gallon oil drum. This I pounded with a sledge hammer in a spiraling pattern around the circumference. As various parts of the surface buckled and rose up they are immediately hit with the hammer bring them down again, even if it means breaking from the spirialing pattern. The drum is hit hardest around the outer circumference, the very center only being hit lightly on the occation that it begins to buckle and rise. This process is called 'sinking' the drum:
When the sink had reached about 6 inches deep in the center (this will take several hours), I marked the areas for each note with a pencil. The size of each note is not critical, because it is only one of many factors that decide the tuning. I made my bass note first in a wild guess as to what the size should be, and though it was far larger than nessassary, I was still able to tune it.
After sketching the first note, I then fit the largest note I could to one side. That would then be my next lowest note. Each note from there was marked to be progressively smaller, shrinking at a rate that would allow 7 notes altogether to fit around the center note of the drum. The purpose of this was to make an 8 note hang, tuned to the D Spanish gypsy scale, otherwise known as the Jewish scale.

The notes from lowest to highest are as follows:

D3, E3, F3, A3, C4, D4, E4, F4

As I already mentioned, the low D note was made too large. The result was a note that still functioned, but must be hit directly in the center to avoid releasing harsh harmonic ringing. The D could easily be fit in the same size area as that of the low E.
When all the desired notes have been outlined, a hammer is taken and is used to beat all surfaces between each note. This provides to raise the note areas as the rest of the pan continues to be sunk. When completed, the surface between notes should be on a perfect curve from one rim to another, the notes standing out from that curve as inward dents.

After completed, the notes must all be tapped around with a nail punch in a process called 'grooving'. The grooving process is what I found to be the most tedious part of building the drum. It is quite hard on the fingers. The groove created around each note must be approximately 2-3 millimeters deep. It is important to be very consistent in the depth because the next step will put much strain on the groove, potentially splitting the drum.

Here you can see me starting the groove, then the drum after completion of grooving:
After the grooving has been completed, if done properly, it should have raised the areas between the notes. That must once again be lowered. At the same time, a hammer is taken and hit along the groove lines and somewhat up on the note. The point of this is to return the grooved areas to be a flat surface by stretching the metal. The process of grooving and once again leveling is done to isolate each note area from the rest of the drum.

That concludes the initial shaping. At this point the drum head should look how it will once completed, with the exception of the unshapen dents in the note areas. The next step is to fire the drum:
Firstly, the note should be made that it is not wise to heat red bricks. They tend to explode quite violently.

Back on subject; the barrel must be cut in two before firing. This would be best done with a torch, sawzall, or a circular saw with a metal cutting disc. As can be evidenced in the above images, I had none of those things available when needed. The drum half of the cut barrel is then placed over a wood fire as is shown. When it reaches the proper temperature the metal will begin to turn gray. Any rust on the drum head will also begin to blue. In the images above, the drum has just reached the proper temperature. Notice the difference in color between the properly heated drum head and the inside walls that have not been heated.

Remove the drum from the fire once the color change has taken place and allow it to air cool.

Wash the entire drum with soap and water before continuing. This should remove most of the rust as well as any remaining burnt paint. Be sure to dry it quickly afterwards so it does not rust again.
The drum should now look like the image on the right. The entire drum head has now been hardened by the firing, this is not what is desired. All the area between notes should be hardened steel, however the note areas themselves should be softer. To accomplish this, each note, which should still be shaped as a convex dent on the drum, is pounded flat. From the underside each note is then again pounded out. This should be done individually to every note area several times.

After about the fifth time pounding a note flat then denting it back out, it is time to begin initial tuning. Tuning is explained in great detail in the book linked to at the top of the page, so I will not go into it in entirety here. I will simply explain some basic concepts.

The notes are not perfect circles, but are elliptical. There are several factors that determine the tuning of a note, but the simplest to adjust is the size. The larger the note, the lower the pitch, the smaller the note, the higher the pitch.

The best way to begin shaping the notes is to start hammering the circular convex note area in a way to shape it into the desired elliptical dent. When the proper shape is obtained the note will begin to ring. If it does not ring out then the note area may need to be pounded flat several more times to soften it further. When the note is ringing easily upon a light strike with a finger, proceed to tune as is described here: http://www.hotpans.se/pan/tuning/building09_tuning.php
The notes should be tuned roughly to the desired pitch, but need not be perfect just yet. The next few steps will bring the notes back out of tune, but It will be much easier for final tuning if the notes are roughly the desired shape and size.

At this point, the remaining skirt of the barrel is cut off at the rim. In the image above I use a pneumatic cutting wheel. It is not difficult to keep from cutting the drum head while taking off the remaining skirt, but care should be taken regardless.

After cutting is completed, the drum must be cleaned of all rust. This can be done with a wire brush as is shown above, or with sand paper. It is important to remove the rust or it will continue to do damage to the drum head under the paint once completed.

Painting is the next step, under which I used several coats of rust preventing primer:
Final tuning is done in much the same way as initial tuning, except that the notes should already be close to their desired pitch. Because there is now paint on the drum, tuning must be done gently to avoid damaging it. Tuning can sometimes also be done from the underside, reducing the risk of damaging the paint.

A guide to final tuning can be found here: http://www.hotpans.se/pan/tuning/building11_fine_tuning.php


That concludes all I have done in my first attempt to replicate a Hang. More to come.