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Building A Unique
ABS Didjeridu

With Tom Bray

If you wish to build an instrument that is distinctive in appearance, sound and playability, then this is for you. The trick, involved here, is shaping the ABS. Altering the shape will give one an instrument of unique character but one that cannot be tuned, perhaps a solo instrument. ABS has gluing characteristics that are superior to PVC in this application. The goal is to taper a 5 ft. length of 3" ABS, create a snap-in mouth piece fixture and give it a texture and feel that will deny it's ABS heritage. It will appear sculpturally organic. One may create slight crooks or bends in addition to the taper. People who see my didjeridus, even those who play ABS, are genuinely surprised to discover that they are actually plastic.
Materials Needed

 

  1. 5 ft of 3" ABS.
  2. 1 ft or so of 1.5" ABS from which to cut shorter pieces.
  3. 1-1.5" ABS cap - Look for ABS caps that are slightly domed.
  4. ABS glue - ABS glue is extremely volatile, read the cautions and heed them.
  5. Six 3" automobile hose clamps.

 

Equipment Needed

 

  1. A saber saw will make the cuts nicely.
  2. A vice is very helpful for holding the ABS.
  3. A socket driver is essential for easy and speedy hose clamp adjustment.
  4. An electric drill and rotary rasp.
  5. Electrical sanding tools or various wood rasps.

 

How To Build It

Mark out and using the saber saw, remove from the 3" ABS pipe a wedge or isosceles triangle that is 4ft long The length of the base of the triangle which is at the end of the ABS pipe should be the difference between the internal circumference of 3" pipe and the external circumference of the union. It is, indeed, a long skinny triangle that you will cut out. A carpenters chalk line makes the "mark-out" a simple matter. Actually make the wedge or triangle about 3'8" and continue from the apex a straight cut of 4". Space the 3" hose clamps evenly over the length of the cut and tighten each a bit at a time until the edges of the cut are drawn together. Insert the 1.5" union into the small end. It should fit snugly. If it is loose, use the saw to remove enough material so that the end clamp will draw the pipe tightly around the 1.5" union. If the opening is too small loosen the end clamp until the 1.5" union can be inserted, then tighten clamp and insert a thin piece of ABS in the gap. After tightening the clamps inspect the fit up. Generally there will be a few places where the fit-up is not very good, simply insert the saw blade into the gap and remove a blades width of material a few inches long from both ends of the gap area where both sides make contact. Then move the nearest clamp to the center of the gap area tighten to see if the edges can now be drawn together. If not, remove more material until a good fit-up occurs. Generally speaking, ABS glue will fill in a blades width gap. The glue will collapse a little bit and you will have apply more in order to build it up. Some glue will fall through to the interior of the pipe. If you want to remove this fall-through easily, put a bit of newspaper in the pipe and remove when finished. Wait approximately 30 minutes between applications when building up with this glue. I don't think you can do this with PVC.

Now that you have a reasonable fit, loosen all the clamps and starting at the apex of the triangle, apply glue liberally to the inside edges. Actually, you will create a mess on the outside around the seam that you are trying to obliterate, don't worry about it. Glue and clamp about 12" at a time. Work quickly!! When you get to the end, swab glue on the inside of the tapered end and on the outside of the 1.5" union and insert all the way for a flush fit with the end making sure not to get any glue on the inside of the union. Clamp quickly and tightly. The glue will collapse where there were mini-gaps. wait 30 minutes and fill in until the surface is at the desired level. Now let this clamped up, abysmal excuse for a didjeridu dry for 48 hours.

We can now make a mouthpiece. If you wish to use only a beeswax mouthpiece, you may lay the wax inside the union. I would like to recommend a 75% beeswax-25% paraffin(canning wax) mixture as this will provide more stability during hot weather. To make an ABS mouthpiece, you will need an electric drill and a rotary rasp. I use a lathe and a 1" drill bit to start the hole, but you can work your way through the center of the cap with the rotary rasp. Consider making the mouthpiece opening oval in shape as this will fit, more naturally, the contour of your mouth. This shaping is achieved more easily if you have the rotary rasp in a drill press. Next, remove the corners that are adjacent the long sides of the opening. This will provide room for your nose and chin. One can see why the domed cap is necessary. When removing corners to make room for nose and chin, you don't want break through the wall of the cap. Now it is time to sand the mouthpiece smooth. Use a short piece of 1.5" ABS to attach the mouthpiece to the 1.5" union that has been glue-welded into the didjeridu. If you want try a temporary beeswax mouthpiece, lay the wax into one end of a 1.5" union and attach the same way as the cap mouthpiece.

Your didjeridu is now dry. Remove the clamps, which isn't easy but by loosening and wiggling them back and forth they will come away from the dry glue. Apply a mouthpiece and see how it sounds.

Texturing and finishing is next. I use a "poly-fan" sanding wheel by Pferd on a high speed angle grinder to remove excess glue and give the entire surface a hewn look. You should be able to use any kind of electrical sander or even hand powered wood rasps to achieve a desired effect. The ABS glue leaves white marks and these can be covered with shoe polish or more surface glue can be added, left to dry and sanded to create a different effect.

Your new didjeridu may have a larger bore than what you are used to and require more air volume to play. Give it time. It will have a higher pitch than an instrument with straight sides of similar length, but I think that all of the things that a good didjeriduist does besides the basic drone contrasts better with this basic drone thereby making the instrument more playable. An instrument this size has a large sound and emits vibrations that you can feel. Some things in your room may vibrate in sympathy.

If you are wondering why I have a lathe, ect., well, I am a sculptor and building didjeridus is a natural extension of what I normally do. I have been building and playing didjeridus for about nine months and recently heard about and ordered Brian Pertl's instructional tape "Echoes From The Dreamtime". It is wonderful. I highly recommend it.

If you have any questions, you can contact the author at dtbray@primenet.com


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