PAN FLUTE MAKING: A TWELVE STEP PROCESS

By David Osborn

Making a Pan Flute – a Labor Intensive Process
The Pan Flute is a hand crafted musical instrument, and one that will test the craftsmanship and carpentry skills of even the finest artisan.  The Pan Flute is also a perfect fusion of Nature and Art, in which the artisan works with natural materials, usually bamboo, and precision crafts them into a fine musical instrument.  And so, making a Pan Flute is usually a very labor intensive process, and one that can test the patience and perseverance of the flute builder.  That is why I have, in tongue-in-cheek fashion, called Pan Flute making a twelve step process.  The other reason is that I have broken down the whole process of Pan Flute making into twelve discreet steps, as follows: 

Step One: Buying and Selecting the Bamboo
Putting a quality Pan Flute together is a lot like putting together a jigsaw puzzle – you always want to be able to reach for, and find, a piece that is just the right size and shape to fit.  This requires having a good supply of bamboo pipes, of all assorted sizes and bore diameters, ranging from the very largest that you will be using, right down to the very narrowest, and every conceivable size and diameter in between.  You definitely don’t want to come up short, so it’s always better to have a supply of bamboo in excess of your needs than to be wanting in any way, or having to “make do” with a pipe that really isn’t everything that you’re looking for.  Besides having a wide selection of pipes of every possible diameter available, the basic qualities desired in a bamboo pipe for making Pan Flutes are straightness, roundness or cylindricality, and hardness and denseness.  A bamboo pipe doesn’t have to be perfectly straight – in fact, few are – but it cannot be too crooked; slight bowing is permissible, with adjacent pipes selected to be congruent in the direction of their bowing.    

Although bamboo can be harvested in the wild, from the grove, for most people, ordering bamboo from a bamboo dealer, or going there in person to buy the bamboo or select the poles, is the way to go.  Bamboo poles in the diameters usually used for Pan Flutes generally comes in lengths of 6 to 8 feet long.  For a standard size Alto Pan Flute (G to g”), select poles from ¾ inch in diameter down to 5/8 inch to ½ inch to 3/8 inch.  For the lower pipes of a Tenor Pan Flute, you will have to buy one inch diameter poles as well, and for the lowest pipes of a Bass Pan Flute, you may even need to go to 1 ¼ inch or 1 ½ inch.  Some bamboo dealers will let you select individual poles to buy if you go in person, whereas others will deal in bamboo by the bale, which is anywhere from about 25 to 50 poles or so.  To be sure, you won’t be able to use all the bamboo you buy, but if you can use even half of it, you are doing well – usually it’s more like a third of the bamboo you buy that is usable for quality pipes.

Step Two: Rough Cutting the Pipes
After you have bought a bunch of bamboo poles of different sizes, the next step is to rough cut them into lengths that are somewhat longer than the length you will finally be using once the pipe is precision cut down to size.  The cardinal rule here is to always cut substantially longer than the final length you’ll wind up using because it’s always easy to cut bamboo off, but not so easy to put it back on.  Generally speaking, the best bamboo for Pan Flute pipes comes from the middle of the bamboo stalk, or culm – there, the walls are usually not too thick and not too thin, but just about right, and the bore diameter is the most steady and constant throughout.  And in the middle of the stalk, there are usually none of the annoying grooves or indentations in the cross-sectional profile of the bamboo that are caused by the branches, which usually branch off only at the top nodes of the culm. 
Although some precision adjustment of wall thicknesses, beyond merely skinning the outer peel or surface off of the bamboo’s exterior, is unavoidable in making a precision crafted Pan Flute, you want the walls to be of intermediate thickness, from 2.5 mm at the top end to 3.5 mm. at the bottom end.  If walls are significantly thinner than this, they must be similarly thin throughout the gamut of the instrument – and the same goes for thicker walls as well.  Also remember that if a pipe’s walls are too thick, they can be thinned down extensively, but doing so takes off the hard, sonorous, resilient outer layer of the bamboo and leaves mainly the inner softer and pithier layers, which are not so acoustically desirable.  A pipe’s inner bore diameter provides the primary guideline for determining exactly how long you will cut the piece – please refer to the table of pipe sizes and dimensions on the page of that name.  Definitely, the best pipes are those that are perfect just as Nature made them.  Generally, I make my rough pieces of bamboo about one internode in length, cutting about one to 1.5 inches below each node.  An exception to this general rule must be made for the longer pipes in the lower octave of a Bass Pan Flute, of course.    

Step Three: Baking or Kiln Drying the Pipes
Bamboo is quite hard as far as woods go.  However, it has one primary weakness, which is a tendency to split or crack easily along the length of its grain.  And so, bamboo dealers will not and cannot guarantee that the bamboo poles they sell you will never crack.  That is mainly because the poles you get at a bamboo dealer are not perfectly cured or dried – and it’s the drying process, particularly if it happens unevenly throughout the pole, that creates the torque and tensions that lead to cracking.  Moister, more humid climates are generally the most friendly to bamboo, because they allow the natural drying process to proceed at a more gradual, even pace, whereas dry climates are notoriously hard on bamboo, provoking cracking.  Wind is another pesky environmental factor that can provoke cracking in bamboo.  To prevent cracking in bamboo, I have found that thoroughly drying the bamboo by baking it slowly in an oven at carefully controlled temperatures is the best way to go.  This process is similar to the kiln drying of fine hardwoods.  After the bamboo is well baked, it virtually never cracks. 
Load the pieces of rough cut bamboo into the oven when it is cold, taking care to place the racks on which you lay the pieces a sufficient distance from the heating elements above and below.  You can load quite a few pieces of rough cut bamboo onto the racks of an average oven.  You will load the bamboo into a cold oven, before you turn on the heat, close the door firmly, then proceed to turn the heat on.  First, turn the oven up to 150 degrees Fahrenheit and bake the bamboo at that temperature for an hour.  Then, turn up the temperature to 200 degrees F for a half an hour, then to 250 degrees for half an hour more – then turn off the heat and, keeping the door of the oven closed, let the bamboo cool down gradually over a period of several hours – or overnight.  It’s possible to bake the bamboo for a half an hour more at a temperature of 275 degrees F, but not absolutely necessary – if you do so, be sure that your oven has an accurate thermostat, and that the temperature does not go over this level. 

Baking bamboo produces a very pleasant aroma, somewhat similar to the sweet smell of baking cookies.  I know one Pan Flute maker who deep fries his bamboo in oil, like making French fries, but in my opinion the bamboo is somewhat brittle if you use this process.  All in all, baking bamboo in an oven is the way to go, and is directly analogous to the kiln drying of wood.  Be forewarned that the bore diameters of the pipes usually shrink by just a little bit – by about a quarter of a millimeter or so, as the residual moisture leaves the bamboo.  Occasionally, a piece of bamboo will crack during baking, but this is actually quite rare; sometimes, small cracks or fissures may appear in a bamboo pipe after baking, but in my experience, these small cracks or fissures do not widen or go anywhere – after baking, the bamboo is pretty much stabilized. 

Step Four: Pipe Selection
Putting together the pipes that will become a Pan Flute is a lot like putting together a jigsaw puzzle – the right pipe must be found to fill every slot.  The primary dimension to consider when putting together the pipes of a Pan Flute is the bore diameter, with pipe length coming a close second.  Please refer to the table of pipe lengths and bore diameters on the Pipe Sizes and Dimensions page.  Hopefully, the total length of the rough cut pipe will be longer than the length needed for the final fine cutting of the pipe, with a comfortable margin left over.  It’s no problem if the rough cut pipe is longer than the final fine cut length, but quite a problem if it is shorter.  The pipes selected for a certain instrument need to be as similar to each other as possible, with its size being the main vector that changes throughout the instrument’s gamut or range – and size is defined as a composite of a pipe’s length and diameter, especially its bore diameter.  Pipes don’t have to be perfectly straight, but adjacent pipes should be curving in a similar or congruent direction. 

Step Five: Fine Cutting the Pipes
After you select the pipes you will use for your instrument, the next step is cutting them down to size.  The lower end of the pipe will be cut off to produce the proper length of the respective pipe, and indicated in the table of pipe lengths and bore diameters on the Pipe Sizes and Dimensions page.  For most of the pipes, their lower ends will be cut off in a slanted fashion, with the long side being on the side of the pipe that is closest towards the bottom of the instrument, or the low pipes that are held firmly in the palm of the dominant hand.  The low pipes should be on your right if you are right handed, and on your left if you are left handed.  Since natural bamboo pipes rarely if ever grow absolutely straight, there will be the problem of how to orient the pipes correctly – selecting the shortest cross sectional axis of the bore to be the front to back or audience side / player’s side axis, the surface of the pipe that lies directly on the Pan Flute mold should be slightly concave and not convex.  If the side that lies on the Pan Flute mold should be convex, the pipe will not seat well on the mold, and will rock back and forth, leading to potential problems in the assembly process. 

The table of pipe lengths and bore diameters, as shown on the Pipe Sizes and Dimensions page, will be your primary guide in fine cutting the pipes down to their proper length.  It’s always a good idea to make your cut a little outside the line, just to be on the side of safety.  Still, the pipe lengths shown in the table will give a sufficient margin to allow for the shaping and sculpting of the bottoms of the pipes to produce an aesthetically pleasing curve after the pipes have been assembled, without any fear of coming up short length-wise. 

Step Six: Pipe Wall Thinning and Bore Work
The Pan Flute is a precision instrument, and that means that the wall thicknesses of the individual pipes should be precision calibrated to be even and consistent with one another, going from a maximum wall thickness of about 3.5 mm at the bottom end of the instrument to a wall thickness of about 2.0 to 2.5 mm. at the top end of the instrument  - and a precisely adjusted wall thickness calibration from top to bottom.  In addition to the pipe bore diameters being precisely calibrated, the pipe wall thicknesses should be as well, so that the outer diameter of the pipe above at its top rim should be ever so slightly narrower than that of its lower neighbor – and so on up the scale, until you get to the very small pipes up at the top end of the instrument. 

There are two basic schools of thought when it comes to how to thin down pipe walls – from the outside, and from the inside, with each of them having their respective pros and cons.  The way I prefer is to thin the pipe walls from the outside until they are of perfect thickness.  To do this, I go, from rough thinning to fine thinning, from whittling to rasping to scraping.  The best pipes are just “scrape and go”, in which all you need to do to thin the pipe wall down to its proper thickness is to scrape the outer skin off of it – but sometimes, the walls need to be thinned down quite a bit more than that.  The other school of thought is to thin down the pipe walls by reaming the inner soft, pithy layer out from the inside with various drills and reamers.  The main rationale for this approach is to remove the soft, pithy inner layer of the bamboo, which is the least inherently sonorous and resilient, leaving nothing soft to dampen the pipe’s sound.  This sounds great in theory, but in practice, it only works if you have a solid, reliable method of reaming out the inside in a straight, uniform manner, as ruts and/or ridges on the interior of a pipe bore will warp, distort or roughen the sound of a pipe. 

In order to have the right acoustical proportions and response, the narrowest part of a pipe’s bore needs to be its upper rim, with every part of the bore below it being at least that width, if not slightly wider – but never narrower.  If the middle or lower parts of a pipe’s bore should be narrower than the bore diameter at its top end, the pipe’s tone will sound false or glassy, and there will be instability of pitch and/or tone quality.  And the octave-and-a-fifth produced by overblowing a pipe will fall flat of the true fifth.  Although most species of bamboo produce pipes whose bores are narrowest at their top end or perfectly cylindrical, some species of bamboo, most notoriously Black Bamboo (Phyllostachys nigra) will often  be narrower at their bottom ends in their natural state.  If this should be the case, the bore needs to be widened at the pipe’s bottom end with a rat tailed file, and the bore delicately engineered to produce a perfectly cylindrical camber or one that is slightly wider at the bottom end.  Doing this straightly and precisely is easier said than done, and takes a lot of painstaking precision.  It is a good idea to precision measure the pipe bores at their top and bottom ends with calipers. 

Slatting and Fitting

Step Seven: Slatting and Fitting the Pipes
A key feature of the authentic Romanian style Pan Flute is that the pipes are slatted or flattened on their lateral sides and fastened together by gluing; this provides the player with a smooth, contiguous surface along which his or her lips can effortlessly glide from pipe to pipe.  However, this step, this process of slatting and fitting the pipes to prepare them for gluing or assembly is also the most laborious and time consuming of the twelve steps involved in making a Pan Flute.  For this reason, someone who wants to make a “quick and dirty” version of a “Pan Flute” will usually find an easier, quicker alternative to slatting, fitting and gluing, which is usually rafting the pipes together by tying them to splints.  Although such instruments are perfectly playable, they are not the authentic Pan Flute, and do not have the potential for efficient playing or virtuosity that the true Pan Flute has.  Slatting refers to the initial process of cutting the lateral slats in the pipes, whereas fitting refers to the process of getting the slats you have cut down to their requisite depths, and of precision fitting them to their neighboring pipes. 

In slatting, slats are created by flattening out the lateral sides of the pipes in order to give them a flat surface along which they can be glued to their neighbors.  The bottom pipe is slatted only on one side – where it interfaces with the pipe above it – and the top pipe is also slatted on only one side – where it interfaces with the pipe below.  All the intervening pipes are slatted on both sides laterally.  Because the pipes of the Pan Flute are assembled in a curved or arched fashion, the slats you cut on the sides of the pipes cannot be perfectly parallel – they must be inclined ever so slightly inwards towards the player’s side.  Getting the right degree of inclination from parallel is part of the fitting process.  The initial cutting of the slats is usually done by whittling away the lateral sides of a pipe with a wood carving knife, although I have on occasion used a small chisel – although I don’t recommend it, and now use whittling exclusively.  After the initial cutting of the slats, the slats are then deepened and fitted more precisely with those of the neighboring pipes; this is usually done either by using scraping blades, or by scraping with the edge of a triangular or half-round rasp. 

After the initial rough cutting of the slats, they can be fitted together by placing them on a Pan Flute Mold, which is essential for both slat fitting as well as gluing or assembly.  Since the proximal or player’s side edges of the pipes are the ones that interface directly with the player by touching his or her lips, it is here that the pipes must be most precisely and uniformly aligned.  And so, a Pan Flute Mold provides the maker with a curved, convex surface upon which to lay the pipes for fitting and assembly, providing precision alignment for the player’s side edges of the pipe rims.  Perhaps the simplest way of making a Pan Flute Mold is simply to take a wooden board, hammer two rows of nails into it about 1.5 feet (45 cm.) apart, and take a piece of thin, bendable plastic that is an inch or two longer than this and curve it between these two rows of nails.  However, in my experience, the curve produced by this simple process is not uniform throughout its length; the best method is to cut another two wooden boards, one at the top and the other at the bottom of the mold, with precisely the right, uniform curve desired, then glue the plastic to these two boards at the top and bottom ends of the mold.  What is the ideal curve for a Pan Flute Mold?  In my experience, the ideal curve is that of a circle with a radius of 12 to 13 inches (30 – 33 cm.). 

The process of fitting the slats so that the pipes interface well with each other is one that can be done in either a quick and perfunctory fashion, or in a more precise fashion – whatever level of painstaking precision, or relative lack thereof, you choose to select, there needs to be a relatively high level of consistency and uniformity in the slatting depths of the pipes from top to bottom.  You shouldn’t have one pair of interfacing slats be cut very deeply with the ones immediately above or below it being cut very shallowly, for example.  The slatting depth between pipes, which is measured by the closest that the inner bores of adjacent pipes come to each other at their narrowest point, is merely one dimension of pipe slatting and fitting.  The slats need to be angled inwards ever so slightly towards the player’s side so that the surfaces of adjoining slats fit together perfectly on the Pan Flute Mold.  Also, when viewed from the tops to the bottoms of adjacent pipes, the pipes and their slats need to be fairly uniform in width from top to bottom.  Twisting or skewing of the slats from top to bottom should also be eliminated. 

Fitting the slats of adjoining pipes and readying them for assembly will test the precision woodworking skills of even the finest craftsman, and how well and precisely the slats are crafted reflects on the caliber of craftsmanship that went into making the instrument.  Are you mainly looking to throw something together in a hurry to get an instrument you can finally play, or are you looking to craft a fine, precision instrument?  The choice is yours.  Ideally, if the requisite care is taken, you should be able to hold two adjoining pipes together at their slats and not be able to see even a sliver of light shining through when you hold them up to the light.  One of the most helpful tools that I have found in fitting pipe slats quickly and precisely is carbon paper.  Rub the interfacing slats of two adjoining pipes together with a piece of carbon paper held between them, and the high areas will be marked in black; these are precisely the areas that you need to file or scrape down to flatten and fit the slats.  A few rounds of fitting the adjoining slats with carbon paper should suffice to get a pretty good fit. 

Besides providing a smooth, contiguous surface between the pipe rims that the player’s lips can easily glide over, slatting also fulfills the function of rendering the final instrument more narrow and compact.  Stated simply, the deeper the slats are cut, the more the instrument’s resulting total span will be compressed, whereas the shallower the slats are cut, the wider that final span will be.  Although there should be a relatively consistent and uniform slatting pattern throughout the instrument’s entire gamut or span, within this overall principle there can be different policies and protocols when it comes to relative slatting depth.  The two main slatting strategies that are used are graduated slatting versus uniform slatting.  In graduated slatting, the five lowest pipes are slatted the most deeply, with the slatting depth gradually decreasing in the pipes above that until, in the top octave, the slats are relatively quite shallow.  Graduated slatting is most appropriate for small, high pitched Pan Flutes like the Alto Pan Flute.  Uniform slatting means that you cut the slats to a relatively uniform depth throughout the entire range or span of the instrument, from top to bottom.  Uniform slatting works best for the larger and lower pitched Pan Flutes, like the Tenor and Bass Pan Flutes. 

Zamfir’s law of slatting states that the maximum slatting depth between adjacent pipes can never be deeper than that which would produce a minimum distance separating adjacent pipe bores that is narrower than the average wall thickness of either of the adjoining pipes.  For example, if two adjoining pipes have an average wall thickness of 3.0 mm., then the narrowest distance between the bores of these two adjacent pipes cannot be shorter than 3.0 mm.  Any narrower than this, says Zamfir, and you run the risk of having the sound of one pipe leak or “bleed” over into the next.  Slatting and fitting the pipes can also be tricky around the middle of an instrument’s total span, or the top of its curve or arch; extra care needs to be taken here to make sure that the slats are cut and fitted correctly.  Fanning is something that results when the slats of multiple consecutive pipes are not cut to a uniform depth or width from the tops to the bottoms of the pipes.  Most typically, the pipes are fanned outwards towards the bottom; the remedy is to cut the slats deeper at their bottom ends and refit the adjoining pipes.

Step Eight: Pipe Assembly
After the slats of the adjacent or adjoining pipes have been thoroughly fitted to one another to your complete satisfaction and you have the slatted pipes exactly how you want them, it is time to assemble the pipes by gluing them together.  I emphasize here that you must be totally ready and satisfied with all your work on the individual pipes up until this point before undertaking the assembly of the pipes because the step of assembly represents a critical turning point, the river Rubicon of Pan Flute making if you will, after which there is absolutely no turning back.  The essential heart or core of a Pan Flute is its particular gamut or lineup of pipes, from top to bottom, and after you glue that lineup together, this essential heart or core of the instrument is set, and there is no turning back – at least not easily, at any rate.  Before assembly, you are free to substitute one pipe for another and wonder which particular lineup or assortment of pipes is best – but not after assembly.  After assembly, the essential heart or core of the Pan Flute is finished, and all the steps that follow are merely those of finishing up the instrument. 

Because pipe assembly is such a critical step in Pan Flute making, I recommend that it not be approached lightly or hastily, but rather with a methodical seriousness, dedication and preparation.  It is always a good idea to do a “dry rehearsal” or run-through of the assembly process, from bottom to top, at least once before the real event.  It also goes without saying that you need to have all the pipes, from bottom to top, all lined up in a row on a table top outside the Pan Flute Mold so that, once the assembly process is started, you don’t have to waste any time hunting around for pipes, or, even worse, to glue one pipe to another that is out of its proper sequence.  You must be in a calm, focused mental state for pipe assembly and not hurried, rushed or distracted in any way if you are intent on doing a good job of it.  Also, it is helpful not to assemble the pipes if your stomach is too empty or at a time when your blood sugar is critically low, because this can disturb your focus and concentration.  I have found that the best time to assemble the pipes is in the evening, so that the glue can dry overnight.  The assembled pipes are a great thing to wake up to in the morning. 

For assembling the pipes, I recommend a good, high quality furniture or wood glue that is of high strength.  Assembly proceeds from the bottom pipe all the way up to the top, with the topmost or uphill slat of the pipe below receiving the glue and the pipe above being placed onto it.  As you glue each pipe up the scale to the one directly below it by placing glue on the pipe below, there are three basic parameters or dimensions that must be checked well as you go.  First of all, is the tilt or pitch of the pipe from side to side correct?  In order to get the right tilt of the pipes, I recommend that, during rehearsal, lines be drawn with a pencil connecting the edges of the bores of adjoining pipes at their closest point, at least for the bottom five pipes, which set the basic orientation for all subsequent pipes.  A correct side-to-side tilt of the adjacent pipes will produce a line connecting them that is unbroken and intact.  Secondly, are the top rims of the pipes pretty much lined up flush with one another?  I say “pretty much” here because if there are minor discrepancies in the flushness of the top pipe rims, this can be remedied in the first step of beveling the pipes, which is to flatten the top rims of the pipes with a large flat rasp.  And thirdly, is each pair of adjoining slats thoroughly glued and affixed, from the tops of the adjoining pipes to their bottoms? 

First, the single slat of the bottom pipe receives a layer of glue as it is placed onto the end of the Pan Flute Mold, with the right tilt to it.  Then, the second pipe up from the bottom is firmly placed next to it, and, after placement, its uppermost slat receives a layer of glue, with the third pipe up placed firmly on the mold adjoining it.  This process repeats on up the scale, until you get to the top pipe, which receives no glue of its own, but is merely adjoined to the glued upper slat of the pipe below it.  The coat of glue that the uppermost slat of each pipe receives is to be moderate – not too thick, and not too thin, for the best results.  My preferred method of applying the glue is the old fashioned way – with the fingers – although you are free to try other methods of glue application.  It is also pretty much essential that all the pipes be glued together in one sitting, because there is bound to be at least a little warping of pipes as the glue dries, and gluing all the pipes together in one sitting, within the space of a half an hour or so, assures that a consistent, uniform warping will occur throughout the instrument’s entire span.  The possibility of excess or undue warping can be reduced or eliminated by a thorough and precise fitting of the slats of all adjoining pipes before assembly, so that all slat surfaces are thoroughly flush and flat to one another.  Let the glue dry for at least 12 hours before proceeding further.  After assembly, if any holes or gaps between the pipes should remain, these can be filled in with glue in a kind of second gluing, but the better you fit the pipes, the less of this has to be done.

Framing and Reinforcing the Pipes

Step Nine: Framing or Reinforcing the Pipe Bottoms
After the pipes of a Pan Flute have just been assembled, the instrument is still a very fragile thing, an “accident waiting to happen”, if you will – until the pipes can be framed or reinforced at their bases or bottoms.  In addition, if the newly assembled pipes are left to stand for very long without being reinforced, their arch or curve can warp more and more over time.  For both of these reasons, I highly recommend framing or reinforcing the pipes and putting the “boot”, “frame” or bottom on the instrument as soon as possible.  Although the main necessity for undertaking this step is structural, to give the instrument adequate strength and reinforcement, aesthetic considerations also enter the picture quite prominently, and it is here that Pan Flute stylists can most express their artistic creativity.  But it must be stressed here that the structural considerations of strength and reinforcement are primary, while the aesthetic considerations are secondary.  What is the use of having a beautiful frame on your instrument if it is still flimsy and fragile, if it is not structurally strong and stable?

The frame or the “boot” of the Pan Flute must be made from special materials that have both the requisite flexibility to be molded to the shape of the instrument’s arch or curve, as well as enough strength to provide sufficient structural reinforcement.  The main material to be used is wood; traditionally, Lemn de Tei, which is Linden wood or Basswood, is the wood that is used for the frame.  Fortunately, Basswood is available, in the requisite 1/16 or 1/8 inch thickness, at hobby stores that sell wood for model airplanes.  I have also found that 3 to 4 laminations or layers of paper thin plywood, also used for making model airplanes, also works well, and may be structurally stronger than Basswood.  Another great material to use is sheets of fiberglass glued on with epoxy, which provides an extremely strong and durable first layer of reinforcement for the instrument.  The end pieces for the frame are usually made from pieces of split bamboo that are of the right size and inner diameter to fit around the ends of the bottom and top pipes.  And the wood is glued onto the instrument either with masking tape if the wood is more flexible, or with clamps.  Layers of paper thin model airplane plywood are fully flexible for easy bending, but Basswood strips may need some steaming or moistening with hot water to soften them up. 

Prior to the actual affixing of the frame to the bottom of the instrument, there are a couple of preparatory sub-steps that need to be done.  The first is to sculpt the bottoms of the pipes into a smooth, aesthetically pleasing curve with a half round rasp.  Because bamboo tends to splinter easily, it is recommended that the outer edges of the sloping bottom rims of the pipes first be rounded off with a rasp as a safeguard against this happening before this sculpting can begin in earnest.  Secondly, if there has been marked or significant warping of the curve or arch of the pipes since their initial assembly, remedial measures can be taken to correct this, and bring the curve or arch back closer to the original ideal of the Pan Flute Mold.  If the arch of the pipes has warped wide or decreased in its curvature, the pipes can be trussed with a thick nylon cord and thick strips of cardboard or folded heavy paper can be wedged into the end, around the lowest pipe, until the arch is tightened sufficiently.   If the arch of the pipes has warped tight or increased in its curvature beyond the ideal, the pipes can be laid upon a table or flat surface and a stone of about 5 – 6 pounds (2 – 3 kg.) or slightly heavier placed over the top of the arch to flatten it.  Thick, heavy books also work well as weights.  While the pipes are being trussed or weighted down, as the case may be, the gluing of reinforcement strips should be done – to the inside curve for the former and the outside curve for the latter.  Then the curvature or arch of the pipes is set, and the rest of framing can proceed as normal. 

There is a considerable degree of flexibility to which the various sub-steps of framing the pipes can be arranged, within certain limits and considerations.  The first goal of the framing process is to remedy and set the correct arch or curvature of the pipes if marked or significant warping has occurred since assembly.  The second goal of the framing process is to provide sufficient strength and structural reinforcement to the arch of the pipes and their curvature, so they are set.  A highly recommended first step in framing the pipes is the laying down of two to three layers of epoxy and fiberglass sheets on the very bottom of the instrument; often, this alone is sufficient to set or stabilize the arch or curvature of the pipes after they have been weighted or trussed.  However, the gluing of the front strip(s) in the case of a tight warping or the back strip(s) in the case of a wide warping is also recommended to set the arch or curvature even more firmly. 

To cut the reinforcing strips of wood for the front, back and bottom sides of the frame, I have found that taping a sheet of heavy brown paper, like from a shopping bag, to the front and/or back of the instrument and tracing the curve of the bottom of the pipes onto it, then cutting out that curve with a pair of scissors, works very well.  You use the same exact curve for both the top and bottom edges of the same strip(s), with merely a wider distance between the two edges at the bottom than at the top.  For example, a distance of 3 cm. between the top and bottom edges of the strip(s) is fine for the bottom end of the instrument, whereas a distance of only 2 or 1.5 cm. is appropriate for the top end.  The reinforcing strip(s) for the bottom side of the frame can also be done in a similar manner, tracing around the entire periphery of the instrument with a pencil to get the proper silhouette or outline.  Just remember to cut the front and back strips at least a centimeter or two longer than needed, to cut off to the right length when the end pieces are added; similarly, the bottom strip(s) are to be cut at least two to three millimeters wider than needed, and then trimmed off later.  An Exacto knife – and/or saw – are the best cutting implements to use for cutting the strips. 

I have usually made the end pieces for my Pan Flute frames from bamboo whose inner or bore diameter is large enough to fit snugly around the outside of the top and bottom pipes; however, other makers have carved them out of wood.  The bottom edges of the end pieces are filed or rasped off to be flush with the bottom surface of the instrument, but their top ends can be carved into various aesthetic designs, which are usually spired or pointed.  It is usually recommended that the last strip to go on in the assembly of the frame is the (last) bottom strip, which is cut to cover the bottom edges of the end pieces, providing an unbroken and uniform surface on the instrument’s bottom end.  The fitting of the end pieces and their joinery with the front and back reinforcing strips is another point to test and show the level of craftsmanship of the Pan Flute artisan.  I trust that you will work out your own best procedure or protocol for doing this joinery work as your craftsmanship and experience unfold and develop.  The most aesthetically pleasing frame is one that appears to be seamless. 

Stylistically and aesthetically, there are several possible variations in the designing of Pan Flute frames.  Although Basswood is the traditional material for making Pan Flute frames, a flexible tree branch, of Willow or some other soft, pliable wood, can also be used for the front and back strips for those who want a very natural feel and look.  Or, the front and back strips can be eliminated altogether, just reinforcing the instrument with successive laminations of thin Basswood, hardwood veneer or thin plywood on the instrument’s bottom surface.  If the right pieces of bamboo or sculpted wood should be unavailable for the end pieces, then molding them out of epoxy putty and rasping or sanding them off smooth later is also a possibility.  The styling variations are virtually endless, and the aesthetic possibilities of using exotic woods and other materials can also provide great artistic and creative possibilities.  Just remember that structural considerations of strength and reinforcement should be satisfied before you start to consider aesthetics.

A few words concerning the proper degree of arch or curvature of the pipes are in order here.  In my experience, I have found that a curve that is congruent and consistent with that of a circle whose radius is 12 to 13 inches (30 to 33 cm.) is the best one to use.  Nevertheless, different instruments, all of them of fine quality, will display a certain degree of variation in the relative tightness or openness of their curve or arch, within limits.  The arch or curvature of the pipes is mainly an ergonomic consideration, to facilitate the moving of the instrument back and forth as the player moves around rapidly between its low and high ends.  In other words, the arch or curvature of the pipes facilitates this up/down movement of the player by utilizing the natural rotation of his or her shoulders and arms around the central pivot of the head, neck and spinal column.  Different players are of different sizes, some with wider shoulders and others with narrower ones, so there is no absolute uniformity of curvature among different quality instruments.  If the arch or curvature of the pipes is too tight or great for you, you will notice a certain muscular constriction or tightness under the shoulder blades when you are at the top and/or bottom ends of the instrument; conversely, a curve or arch that is too wide will induce undue stooping forward and downwards of the head and neck as you play.  You must feel that the instrument comes to you, and not that you have to go to it.  I highly recommend that you first test how the arch or curvature of the pipes feels to you before you adjust it with the remedial measures I have recommended, and certainly before you begin framing the pipes.

The previous nine steps, the first three quarters of the Pan Flute making process, were the preliminary steps of putting the instrument together and getting its basic framework set and solidified.  The last three steps are truly the steps that involve finishing up the instrument – refining it, adjusting it, tweaking it, and otherwise preparing it to perform.  These last three steps, and the sub-steps that comprise them, can actually be done pretty much concurrently, especially the first two of them, which are quite interdependent and intimately involved in adjusting and refining the Pan Flute’s tuning and playing response.  So, without any further ado, here they are…

Beveling the Pipes

Step Ten: Beveling the Pipe Rims
In Romanian Pan Flute maker’s parlance, the whole process of beveling the upper rims of the pipes is often referred to as putting a buza or “mouth” on the pipes.  The whole purpose of beveling the upper rims of the pipes is to give the pipes a mouth that interfaces more comfortably and intimately with the mouth and lips of the player.  The benefits of beveling the pipe rims are: a more polished, refined sound and tone; a better and more sensitive playing response; and an easier and clearer playing of the chromatic notes, which are produced by lipping down on the pipes.  Beveling also smoothes things out; just try moving your lips back and forth over the rough, sharp rims of the un-beveled pipes!  Beveling the upper rims of the pipes is a highly individual matter, and each player has his or her own preference; therefore, pipe beveling styles can vary widely between different players.  Because beveling the pipe rims is putting a mouth on the pipes to fit the player’s own mouth or embouchure, the basic guideline or recommendation here is that beginning players bevel the top rims of the pipes only very lightly; then, once their embouchure is stronger and more firmly set, they can progress to a deeper or more extensive beveling of the pipe rims, as their natural inclinations lead them.    

This whole matter of pipe beveling is not only a highly individual one; it is also quite delicate, sensitive and complex.  And so, I will devote a whole article to discussing the different styles of pipe beveling, and the pros and cons of each.  With this in mind, I will now proceed, quite simply and directly, to tell you how I bevel my own pipes, in a step-by-step manner:

The first step in anyone’s pipe beveling process is to file or sand the tops of the pipes absolutely flat.  This provides a straight and steady baseline from which all subsequent beveling of the pipe rims can proceed.  My preferred tool for doing this is a large flat rasp or bastard file; it is possible to mechanize the process with a belt sander, but care must be taken that the pipe tops are sanded very lightly, the minimum amount necessary to flatten the tops into a level surface.  After this is completed, and a satisfactory level surface is thus created, the next step is to round off the outer rims of the pipes, both on their front and back sides – make them nice and round.  This will create the first smooth and comfortable surface against which your lips can glide easily.  The other reason for rounding off the outer edges of the pipe rims is that bamboo splinters very easily, and if this is not done as a preventive measure, splintering is very likely to occur with further filing and beveling. 

With each of the pipes thoroughly rounded off on their outer rims, on both their front and back sides, what I then do is to further file off or round off the pipe rims on the player’s side, in a unilateral direction straight toward the player.  This will create a slight scalloping of the pipes’ inner rims, exposing a bit of the inner bore surface on the far side of each pipe.  To do this, you can use either a small half round file or a small flat file wrapped with sandpaper of medium grit.  Then, using a small flat rasp with medium grit sandpaper wrapped around it, I will then round off the far rims of the pipes in a similar fashion to what I have just done with the near rims, only much more slightly – just enough to create the slightest “dip” in the profile of the far rims.  Then, using the small flat file wrapped in medium grit sandpaper yet again, I will set a slight inclination downwards towards the player’s side in the space between the near and far rims of the pipes, effectively tilting or inclining the original level playing field ever so slightly towards the player.  Then I will round off, again in a unilateral direction directly towards the player, even more deeply than I did at first, scalloping the near rims even more and revealing more of the inner bore surface of the far end of the pipe’s interior.  I will then test the tone and playing response of this basic beveling pattern or shape by blowing on some pipes, and if I am satisfied with the results, I will then sand the surface even smoother with finer grades of sandpaper.  The last step is to use medium fine sandpaper to gently round off the inner edges of the pipe rims so that everything is left smooth, and no sharp, harsh edges remain.

As with slatting the pipes before assembly, the key to a successful beveling of the pipes lies in consistency and uniformity.  There shouldn’t be any significant differences in beveling angle and depth from one pipe to the next, or between adjacent pipes – all should be smooth, regular and even.  If the pipe beveling should be irregular or uneven, the player will have to adjust his or her embouchure and blowing angle or technique from one pipe to the next, which doesn’t make for very efficient and smooth playing.  With smooth, uniform beveling of the pipes, all the pipes of an instrument will speak in sync with one voice.  If we were to draw an analogy between the Pan Flute and the guitar, the beveling of the pipe rims is analogous to the fine adjustment of the height of the strings above the frets in a guitar – both are crucial to determining a smooth, uniform playing action and response, whether it be with your fingers over the strings of a guitar, or with your lips and breath over the bamboo rims of the pipes of a Pan Flute.  In beveling the pipe rims, I recommend that you proceed gradually, in stages, beveling and tweaking the pipes until you hit that “sweet spot” of perfect tone and playing response.

Step Eleven: Tuning the Pipes
A common comment that I hear from people when they find out that I make my own Pan Flutes is that it must be very hard to cut the pipe to precisely the right length to produce the desired note or pitch.  Actually, the lengths of the pipes constitute the least exacting aspect of Pan Flute making.  Just as long as the pipes are longer than the minimum length that they need to be for producing their desired pitch, plus a comfortable tuning margin, they are then tuned up to pitch by the insertion of tuning material, which is packed down into the bottoms of the pipes.  The pipes of the upper octave of an Alto Pan Flute are more than halfway full of tuning material; if they were the exact length that they needed to be to produce the desired pitch, they would be too short to hold comfortably with the fingers.  The traditional tuning material used in the Romanian Pan Flute is beeswax; its advantages are that it is flexible and malleable, and readily sticks to the bottoms of the pipes, sealing off the bottoms as well.  Its main drawback is that it expands quite a lot in hot weather, which tends to raise the pitch of the pipes. 

The more beeswax or other tuning material that you pack down into the bottoms of the pipes, the higher the pitch gets; conversely, the more you remove or take out, the lower the pitch gets.  Tuning the pipes with beeswax actually serves a dual function; in addition to tuning the pipes to the desired pitch, it can also seal the bottoms of the pipes so that no air escapes, if this has not already been done by another method.  Since sealing the bottoms of the pipes can also be done in the ninth step of framing the pipes, there can be some overlap here between the ninth and eleventh step of Pan Flute making, especially in achieving the first objective, which is sealing off the bottoms of the pipes.  The tuning of a pipe generally proceeds in three stages: 1) sealing off the bottom of the pipe; 2) rough tuning of the pipe; and 3) fine tuning the pipe.  I will now proceed to discuss each one of these stages and objectives in turn.

The initial sealing off of the bottom of a pipe so that no air can escape, and so the pipe may produce a clear sound when it is blown into can happen as early as the ninth step, which is that of framing the pipes.  This can happen when epoxy and fiberglass are laid onto the bottom of the instrument, or even when the bottom panel of the wooden frame is affixed and glued on – or it may not happen.  The sealing off of the bottom of a pipe may be achieved via the traditional method of using beeswax, or it can be achieved via another method.  Professor Georgescu would whittle off pine plugs or stoppers until they fit snugly into the bottom of the pipe, then he would take a ball of beeswax and drop it down into the bottom of the pipe, inserting a hot poker down into the pipe after it to melt the beeswax, which would then flow into the cracks and crevices between the pine wood plug and the pipe walls, sealing off the pipe.  He did this with the individual pipes, even before assembly.  The easiest way is simply to wait until after the bottom frame has been put on the pipes and seal them by packing in beeswax or another tuning material, like epoxy putty or some other form of putty. 

The next phase of the tuning process is rough tuning.  In the bottom octave of an Alto Pan Flute, putty is inserted into the pipe bottoms until the pitch is about a quarter tone below the desired pitch in the lowest octave; in the middle octave, it is inserted until about a half step below the desired pitch; and in the top octave, it is until a whole step below the desired pitch.  Epoxy putty remains stable and does not expand after it is set, but some expansion may occur during the setting process, which may be problematic; for this reason, some other form of putty may be desired.  Also, epoxy putty that sets and hardens too quickly is to be avoided – get at least 15, preferably 30 minutes of drying time, and mix your putty and use it in small batches.  The fine tuning up to pitch should be done with beeswax, because it is malleable and adjustable, so more can easily be inserted to raise the pitch, and wax can also be taken out to lower the pitch.  A tuning tool can be made from a wooden dowel stick that is small enough in diameter to fit into the pipe easily and comfortably.  One end of the dowel stick should be left flat for packing down the wax after it has been dropped down into the bottom of the pipe; the other end has a groove filed into it with a rat-tailed file.  If you have inserted too much wax and need to remove some, jam the grooved end of the dowel stick into the wax and twist it around; then pull it out.  Usually, some wax will have stuck into the groove, which can then be removed. 

Pan Flute tuning is a rather tricky process, and one that is not that well done by a beginner.  This is especially true of the high notes, especially those that are above the “d” of the middle octave or register of a standard Alto Pan Flute.  Beginning players generally find that the pitch of these notes is unstable, and easily sags, because they have not developed sufficient embouchure strength and support.  And so, Pan Flute tuning is best done by a seasoned or advanced player.  Using an electronic tuner is recommended, but it must not be relied upon exclusively – use your ear as well.  In the lower octave of an Alto Pan Flute, the pitch is inherently stable.  In the middle register, the pitch gets somewhat less stable, tending to rise with a more forceful air stream and embouchure, and to fall with a less forceful one.  And these tendencies are even stronger in the top register.  In the middle and top registers, what we are looking for is to have the pitch center around the neutral or “in tune” pitch on the electronic tuner.  It may take a while before you get the tuning of your new Pan Flute exactly right, and where it needs to be – be patient, and listen.

Step Twelve: Oiling and Finishing the Pipes
In the twelfth and final step of Pan Flute making, we get to the real finishing touches that are to be put on the instrument, to protect and beautify it.  Before this step, the Pan Flute is perfectly playable in every way, so if playing an instrument that is not fully finished doesn’t particularly matter to you, then go ahead and play your heart out.  But these two final finishing processes, of oiling and painting the pipes, will not only beautify your instrument, but will also protect it and extend its life. 

Oiling the pipes usually comes first, and can be done periodically to protect the pipes from the moisture of the player’s breath, and subsequent tendencies for mold and rot to set in.  Oiling is done as part of the final stage of Pan Flute making, and then subsequently as part of a cleaning or overhaul process.  In this cleaning and overhaul process, the interiors or bores of the pipes are first cleaned of mold and mildew, as well as solidified residue or accretions from the player’s breath, with a long, thin dowel stick to which a strip of wet cloth has been attached.  My teacher, Damian Luca, recommends using just ordinary water for this procedure, in contrast to others, who prefer a stronger cleaning solvent like wood alcohol, which he says tends to overly dry out and damage the bamboo.  After the pipes are initially cleaned in this manner, they are then oiled.  In the initial making of a Pan Flute, however, we may proceed directly to the oiling process without doing an initial cleaning. 

Many different types of oil can be used to oil the pipes of a Pan Flute.  Zamfir’s personal favorite is Almond oil; Damian Luca says that any vegetable oil from the supermarket will do.  Oils that I have used include Castor oil, Grapeseed oil, Linseed oil and Olive oil.  You can even get elaborate in making your own composite oil blend, or even in making a semi-solid bore wax that includes other protective materials like Myrrh or Propolis resin as well as Beeswax into the mix.  The whole purpose of oiling is to protect the wood from moisture and rot.  You can prop up the Pan Flute into an upright position, either by taping it to the wall or inserting its bottom end into a wide mouthed jar that has been weighted down with sand, gravel or coins, so that it sands upright in a stable position.  Then, using a measuring cup with a beak on it, and maybe a funnel as well, pour the oil into each pipe, from the bottom pipe to the top, until the oil level rests right below the rim.  Then, let the instrument sit overnight in this position, soaking up the oil.  In the morning, pour the oil out and turn the Pan Flute upside down, rims downward, over several layers of newspaper to soak up the excess oil that slowly drains out over the next several hours.  If this seems too messy and wasteful of oil to you, then an alternative method is to apply the oil with a thin, long stemmed paint brush, even using two applications if so desired.    

After the pipes have been oiled, and the excess oil has been thoroughly removed, the next step is to finish or paint the pipes.  The purpose of painting or finishing the pipes is mainly aesthetic in nature, but it can have acoustical benefits as well.  A wide variety of different finishes may be used, such as acrylic lacquer, oil finishes, polyurethane, or various kinds of varnishes, including acoustical violin varnish.  I highly recommend the latter, as it not only beautifies and preserves the bamboo, but also improves the overall sound and acoustics of the pipes.  Or, you may simply wax or oil the outsides of the pipes, as you have done with their interiors, or apply no paint or finish at all, preferring to go natural.  A glossy finish is most recommended for the bottom frame or boot of the Pan Flute, even if the pipes themselves are left in an unfinished, natural state; one of the things I have done with the frame or boot has been to apply a very thin layer of clear epoxy glue to it, using a very thin piece of plywood as a kind of palette knife applicator for doing this.  The frame or boot may also be stained to get it to be the right color, and even brown or black shoe polish can be used for this purpose.  If you have good basic woodworking and craftsmanship skills, you will be able to come up with a good creative and aesthetically pleasing solution.

So that’s it – a basic run-down of the twelve step process for making a Pan Flute.  May it serve you well!