Woodwind Materials

[Enthalpy]

Hi everybody,

Many woodwind instruments use a single or double reed made of cane (through plastic catches up). They cost some money, double reeds also take much effort, and with luck a reed lasts for two weeks.

I've a strong intuition that the 10⁷ cycles of strong bending weaken the cane. But some people claim that soaking for 2-3 minutes before playing lets double reeds lose some fluids over time and this alters the mechanical properties.

Following that explanation, I propose to keep double reeds longer by soaking them in some mixture or solution that contains the fluids that would be lost. The concentration shall reduce, compensate or reverse the loss of the fluids.

One could try to analyze used soaking water and seek an equilibrium concentration of the several fluids for the magic bath. Or more simply, soak a load of unprocessed cane (waste) for an hour in water, and concentrate the juice until reeds don't lose anything more.

The best commercial form would be granules or concentrated drops that the musician puts in the water before soaking the reed. This might avoid bacterial growth. Perhaps some disinfectant like silver would help. The taste matters.

The budget for double reeds is like 200€/year, and musicians would spare efforts and keep their best reeds longer. If some effect is observed on single reeds, more musicians are interested. A handful of small companies live from reed making.

Marc Schaefer, aka Enthalpy

[Enthalpy]

If stretched or rolled polyketone becomes stiff and keeps damping, it can make a superior material for wind instruments.

Marc Schaefer, aka Enthalpy

[Enthalpy]

The company Vibrato markets plastic saxophones, with walls of moderately thin polycarbonate, and even pads of elastomer. Here it there
IruxMK3p_jY Plastic vs metal
vTZzFIt2raw at t=58 Plastic
G5ev6izRxpM Both

The difference is huge. Thin polycarbonate makes a muffled tone and sounds just like plastic. Exactly like a plastic trumpet does, or the clarinet of thin injected plastic I tried years ago. The records can't tell how much the covers and pads contribute.

At the oboe with thick walls and normal covers and pads, polycarbonate didn't behave that poorly as compared with Dalbergia.

Some physicists still claim the material has no influence, essentially because they can't explain it, and because an influential ancestor botched that. Flawed reasoning.

Marc Schaefer, aka Enthalpy

Edited June 21, 2020 by Enthalpy

[Enthalpy]

I reported palm oil here on January 31
scienceforums
and someone reported success with bag balm on corks
wikipedia
so I tried. The composition varies a lot, I chose the weakest smell at the drugstore, this one contains petroleum (from mineral oil), paraffin (again from mineral oil), and in third position vegetable oils, plus minor things that don't lubricate.

• Very efficient lubricant too.
• The consistency makes spreading easier that the solid palm grease.
• The weak smell is too much for me, so I go back to palm oil. Individual choice of course.

To understand why the oil must be replenished, I impregnated paper with palm oil 2.5 months ago. Despite ~57 C+O atoms per molecule, the paper has significantly dried now. I believe this is evaporation, because palm oil isn't sensitive to oxidation, and the paper feels grainy and looks more opaque again. However, evaporation is too slow to require new oil on the corks after a week. Meanwhile I must clean away oil from around the corks, so it's just swept away by repeated assembly and disassembly.

Edited July 24, 2020 by Enthalpy

[Enthalpy]

Bassoon balancer v3. The string coming from the boot joint is redirected by a loop that now has its ends parallel to the body, while the ring perpendicular to the body passes straight over the loop. This v3 is much easier to build and to adjust.

Still adhesive tape, about 3 plies. At the loop, two foldings give 90° each, and an added short tape part neutralizes the sticking side.

V3 too provides perfect roll balance and leaves some weight on the left hand, since an attempt with perfect pitch balance was unplayable.

The adhesive tape always separates from the concave portion of the tenor joint, so instead of sticking it there, this time I gave it roughly the loose length left by the spacing to the bass joint.

Marc Schaefer, aka Enthalpy

[Enthalpy]

4c definitive version of my bassoon balancer. Easiest to build and adjust. Time will tell if it's the most durable.

4 plies of adhesive tape parallel to the tenor joint hold a ring. I superimposed the 4 plies first, holding the first ply between a desk's edge and my fingers. The tape needs some length to hold on itself near the ring. Several turns of a second tape around the joint holds the first tape against the joint as previously.

Duct tape (Gewebeband, toile adhésive) crept and began to tear at the edges. Surgical tape (Pflaster, sparadrap) crept, and the European tan looks silly on African wood too. Plain office adhesive tape is best up to now.

Duct tape and surgical tape crept at a D-shaped ring until holding at a corner, so a round ring is less bad.

Do use the shoelace that holds at the boot! It saved my instrument a dozen times.

Marc Schaefer, aka Enthalpy

[Enthalpy]

I have used a dozen times isopropanol to clean one bassoon reed and to disinfect it from bacteriae and virus.

This reed is very old and it becomes dull and unresponsive when a biofilm develops inside. Isopropanol eases much the mechanical removal of this biofilm (some bassoonists use a pipe scraper), often no mechanical action is needed. I give some drops in the reed at the bocal end over my usual plastic soaking box, then I soak and shake the reed for about 1min in the flown isopropanol.

The cleaned reed becomes responsive again. Could the biofilm be the cause of reed ageing?

Isopropanol, or isopropyl alcohol, is what gives hospitals their odour. It must be concentrated >70% but not pure. Its deadly dose is half that of usual alcohol, so rinse the reed. Concentrated usual alcohol (ethanol, ethyl alcohol) should work identically; I'd stay away from methylated spirits, whose denatonium tastes so badly. I haven't tried vodka &co, normally it's 40% ethanol so its antiseptic action isn't guaranteed.

My bassoon reeds are covered with wax to be airtight. Perhaps the more usual varnish dissolves in isopropanol and ethanol.

Marc Schaefer, aka Enthalpy

[Enthalpy]

The 4d version of my bassoon balancer has arrived! The triangular ring shall spare the adhesive tape. The tape hasn't crept to the side after 90min practice. I found only thick big rings.

The adhesive tape showed no wear nor tear after two weeks at the round ring, but I wanted to move the ring sidewise anyway.

 

Marc Schaefer, aka Enthalpy

[Enthalpy]

To scrape a bassoon reed, a plaque inserted in the thin cane supports it and makes it convex. My plaque is made of bone.

The material offers the proper hardness to be filed or sanded at decent pace and resist accidents when scraping the reed. This seems better than the usual plastic or metal.

Sand paper doesn't let bone dust stink like machine tools do.

My raw material was already a commercial part, so I can't tell what bone of what animal it was. Ask the butcher.

Marc Schaefer, aka Enthalpy

[Enthalpy]

I eventually checked what encompass the LCP polymers I suggested for instrument parts.

LCP (liquid crystal polymer) is a very broad class of polymers that includes varied chemical families and properties, some adequate here, others not. Instrument parts need thick raw material, not just fibres, and they need stiffness, possibly after stretching. Some of the thermoplastic LCP can be injected, say for brass and single-reed mouthpieces, but luthiers use to shape parts by turning and milling rods up to now.

Vectra, from Ticona-Hoechst-Celanese-Kururay-andsoforth, is just one seducing LCP. Vectran is the name as a fibre. A950 is one unloaded Vectra.
tools.celanese filter LCP and Vectra
There are dozens LCP more, some fit the present use, others like aramides exist only as fibre. One list of LCP there
plastics.ulprospector
Many exist only with fibre load, which uses to blunt the chipping tools, so I guess stretching the pure polymer for stiffness is better.

Stretching in one direction, say L, expectedly loses stiffness along R and T. So what anisotropy is acceptable? Take a body joint with ID=14mm OD=24mm L=300mm and arbitrary E=10GPa rho=1300kg/m³. The elliptic deformation resonates at 28kHz and bending at 0.76kHz, so E_L*37 and (does it?) E_T/37 would bring both to pleasant 4.6kHz. Though, A950 fibers near "only" 100GPa, so the cold or lukewarm stretch can be strong if not embrittling along R and T. Work-hardening must also ease the subsequent chip machining, up to some hardness limit.

I got vague hints to the price of Vectra A950 pellets
10-25usd/kg Alibaba
55usd/kg Alibaba
while a fabric is logically more expensive
100€/kg fibermaxcomposites
Hoechst-andsoforth can extrude pellets to bars.

But how expensive is grenadilla Dalbergia melanoxylon? Openly available data is even less accurate: supposedly for lesser quality but for tiny customers
60usd/kg rarewoodsusa

So cornettos, tárogatók and all woodwinds except the lower saxophones can afford equally Dalbergia or Vectra. But there are more elements of comparison

• Dalbergias cross borders uneasily and get rare, big parts more so.
• Most LCP are insensitive to moisture, wow.
• Temperature does little to LCP, not even expand it.
• Dalbergia needs decade(s) drying in near-net shape at the luthier.
• Polymers let try new instrument shapes immediately.
• Some polymers are stiffer than Dalbergia.

Marc Schaefer, aka Enthalpy

[Enthalpy]

Bassoon players, and oboe players supposedly too, use a reed reamer to fit the bore on the end of the conical bocal.

My bocal's end diverges by 1:50 or 1.15°. Reamers sold for that purpose (with a handle on the photo) diverge much more strongly, to fit varied bocal diameters I guess. Consequently, the reed fits only the bocal's tip and is wobbly.

I bought for 22€ a used conical reamer for mechanical workshops. 1:50 is a standard, but 1.5° did the job: the difference is 50µm over 8mm fitting length, which the cane absorbs. The reed doesn't wobble any more. A handle isn't mandatory, but mind your fingers with a new reamer.

My bocals are D=5.20, 5.30 and 5.50mm wide at the tip. The reamer starts with D=5.50mm, its nominal diameter, not 0.2 or 0.3mm narrower as sources claim. The narrower bocals perceptibly hit the bore's end and roll more easily in the reed, so I may try a D=5.00mm reamer. At 1:50 diameter slope, a 0.3mm narrower reamer plunges 15mm deeper in the reed's throat, which must change the sound a lot.

One could also have one reamer per bocal, possibly grinded to the desired diameter, but one reed wouldn't fit all bocals. Or better, all bocals could bear extra thickness at the end, machined to a cone with bigger standard slope and diameter. I have one such bocal.

Marc Schaefer, aka Enthalpy

[Enthalpy]

Some prospective thoughts about electroformed hard nickel alloys (for keys, body parts) there:
scienceforums

[Enthalpy]

On 1/27/2021 at 3:31 PM, Enthalpy said:

The 4d version of my bassoon balancer has arrived!

Broken after 51 days, that is 76h practice. Redone in 5mn, but durable would be better.

[Enthalpy]

My bassoon balancer v5 adds adhesive tape in two directions to hold the triangular ring closer to the body. This limits the stressing angle where the two previous tapes cross and hopefully spares the tapes.

The method to superimpose tape plies applies further.

A professional embodiment would use durable materials like polymer film (Mylar etc) or fibres, good glue (like epoxy), something lighter than the thick steel triangle.

It would also prevent carrying the instrument only at the tenor joint. The shape of the part could be open, or completely different, with one other part on a strap originating at the boot fitting at the part at the tenor joint.

Marc Schaefer, aka Enthalpy

[altaylar2000]

Wood always deafens the sound, because it does not resonate like metal

[Enthalpy]

I proposed that the walls' elliptic deformation couples with the air column, here on
Nov 13, 2017 and Nov 26, 2017 and more

Here are examples of resonance frequencies (at 4 nodes per turn) for some parts of common instruments. Young's "transverse" modulus isn't well documented for dense wood, I just took a tenth of the lengthwise modulus. Dimensions are from memory.

Computed from µ*(2*pi*F)² = EI*k⁴
with µ=e*rho, I=e³/12 and k*pi*D=4*pi

   F    Dia  Thick   Et       rho     Mater               Instrum
  Hz     mm    mm   GPa     kg/m3
======================================================================
 6k    11.8   0.4?   83     10300     Sterling silver     Piccolo
18k    15.3   4?      2.1    1050     ABS                 Piccolo
16k    15.3   4?      2.0?   1310     D. melanoxylon      Piccolo
======================================================================
 2.4k  40     4?      1.7?    975     B. Sempervirens     Tarogato
 2.3k  40     4?      2.0?   1310     D. melanoxylon      Tarogato
 4.6k  40     3.7    10      1400     LCP                 Tarogato
 1.0k  36.5   0.5?  114      8550     Brass               Soprano sax
======================================================================
11k    18.6   4       2.0?   1310     D. melanoxylon      Clarinet
11k    18.6   4       2.5    1410     Ebonite             Clarinet
 3.6k  15.6   1       1.3     905     PP                  Clarinet
======================================================================
 210   80     0.5?  114      8550     Brass               Tenor sax
 158   81     1?      2.1    1050     ABS                 Tenor sax
======================================================================
 0.8k  63     3?      2.2?   1025     D. spruceana        Bassoon
 0.8k  63     3?      1.2     590     A. pseudoplatanus   Bassoon
 0.7k  63     3?      1.3     905     PP                  Bassoon
 1.1k  62     2.2    10      1400     LCP                 Bassoon
======================================================================

• For thick-walled narrow instruments, the elliptic deformation is a worry mainly at the bell.
• There, stiffening rings look archaic but can be useful
  scienceforums
• Bassoon bells walls are already thicker around the tone holes.
• Thicker walls at a bassoon's bass joint and bell (not elsewhere) raise the elliptic resonances. Azimuthally stretched polymers, even PP, would improve. Comparison at same mass would be fairer to Acer pseudoplatanus.
• Thick banal polymers equal wood against the elliptic deformation. LCP outperforms wood of same mass, more so if it can be stretched. Wound graphite fibres would improve bells.
• Thin injected polymer is bad, as known experimentally. Lower resonance and smaller impedance. Wall losses explain the dull timbre and the lack of blowing resistance.
• Saxophones are in trouble, with resonances in the hearing and playing range. But at least one excellent luthier (grüssdi!) vehemently denies it.

The elliptic deformation is supposed uniform over the whole length. This tells only the lowest resonance. The elliptic deformation can also be offset by 90° between antinodes adjacent longitudinally, which creates many resonances at close frequencies. The tone holes lower all frequencies.

Bending modes reshuffle the comparisons. Wood's lengthwise modulus outperforms most polymers. Wall thickness matters little, good for metals.

Marc Schaefer, aka Enthalpy

On 3/30/2021 at 7:32 AM, altaylar2000 said:

Wood always deafens the sound, because it does not resonate like metal

Thanks for your opinion!

[Enthalpy]

I compute elliptic resonances for unloaded and complete cylindrical sections for simplicity, but real cases are worse. For instance a flute blowhole adds a raiser and a lip plate whose mass lower the resonance.

As a cylinder resonates but higher than flute's C, the metal tube around the blowhole resonates within the fundamental's range. Possible explanation why a wooden head emits the high notes more easily. Plus, the harmonics fall well within the resonance range.

I propose to stiffen metal headjoints with oblique sheets that start at the raiser, preferably at the angle with the lip plate, and end tangentially at the tube.

==========

Several struts ending tangentially at a tube make a stiffer aggregate than the usual single strut ending perpendicularly on some stiffening part brazed on the tube. I suggested it for a baritone oboe, combined with the keys, there
scienceforums
but tangential ends apply to many more instruments, for instance saxophones or low clarinets, also independently of the keys. If desired, pyramids bring stiffness in all directions. The struts can be tubes flattened at the ends, sheets optionally bent as thicker profile, cast or forged or machined parts: many options exist.

Marc Schaefer, aka Enthalpy

[Enthalpy]

I've tried Stroh Rum 80 and again isopropanol on bassoon reeds since the Jan 18 message here.

80% ethanol Stroh Rum is a drink of repute as a cheaper antiseptic too. It smells strongly, colors the reed and destroyed one. It also corrugates the mouth's skin. Maybe dilution to 70% would save the reed and the mouth, but I didn't try again.

Isopropanol (1L for 5.90€ on eBay) regenerated one more reed that became responsive and clear-voiced again but not tinny, without any mechanical action. Cleaning mechanically the reed inside hadn't brought this. Maybe isopropanol removes the damping biofilm better while sparing the cane and its strength. This reed is varnished at the shaft, and I dipped only its tip.

70% ethanol (without tannin) would smell better but is expensive, so I haven't tried yet.