Checking for Leaks

Feeler gauge with Mylar

If you walk through the finishing department at Powell, you will undoubtedly find our finishers "sweeping" a little stick around each pad several times -- or at least this is what it may look like from afar.  But, this small, very manual device is actually a feeler gauge -- and the finishers are checking for leaks.  You have probably heard a few repair technicians, fellow players, and teachers talk about leaking pads, and our finishers make sure that there are no leaking pads on the flutes that they are finishing.

So, what exactly is a leaking pad?  Well, it can seem a bit misleading, since it's not exactly the same as a tire leaking air.  When checking for leaks, it's actually the pad seal that is being tested to make sure there are no leaks.  In simpler terms, when the key cup closes and the pad covers the tone hole, are there any gaps between the pad and the edge of the hole?  The answer should be no, because we all know what the result would be... You see, the air you put through the flute could escape or "leak" through if the pads are not sealing against the tone hole, and you would find it difficult to play the notes you are expecting to come out! 

Using the gauge around the pad to check for leaks

Finishers and repair technicians have different techniques for checking for leaks, but we caught up with finisher Karl Kornfeld at Powell.  He showed us two feeler gauges which were both small "sticks" with a feeler paper on the end.  One gauge used cigarette paper, which is .001 of an inch thick.  This is the traditional type of gauge that you may have seen your technician use or that you may use yourself.  The other gauge, which is the one Karl and the other finishers use, has a piece of Mylar at the end.  Mylar is .0005 of an inch thick, which is definitely thinner than the cigarette paper and (therefore) more precise in detecting leaks.  Karl uses a general "sweep" around the pad with the gauge to see where there may be leaks.  He then goes around the pad clockwise, drawing the gauge out to check various spots.  He says the pressure should be even as you check, and you should draw the gauge out with the same motion -- just to keep everything consistent.  Although he usually begins checking pads with a "sweep," in the video below, you will see him draw the gauge, then circle around with the "sweeping motion," and repeat the drawing motion.  Oddly enough, he also told us that Mylar is the same material used in Pop Tart wrappers!  Obviously, the Mylar on the feeler gauge is much, much thinner --- thank goodness.

The Gold in a Gold Flute

By Steven A. Wasser
President, Verne Q. Powell Flutes

The prices for precious metals have skyrocketed over the past few years.  In this environment it’s easy to get fooled into thinking a flute has more gold than it really does.  So here are some tips on evaluating “gold” flutes:

•  “Solid Gold” generally means that the flute has been made from some version of karat gold ranging from 10k to 24k.  An item that is 24k karat gold is comprised of 100% gold - 14k contains 58.4% gold.  The rest of the 14k gold alloy could be any combination of precious metals (like silver or palladium) or base metals (like copper or nickel).  The metal content in the alloy often varies by manufacturer.

•  “Low Karat Alloys” with less than 10k of gold are becoming more common as the price of gold rises.  For Tiffany’s 175^th anniversary they introduced a low karat rose gold alloy they have trademarked as “Rubedo .”  This is a growing trend as manufacturers are looking to provide flutists with gold instruments at more reasonable prices.

•  "Gold Filled” items are essentially laminates, where the outer layer is gold that has been bonded or fused to an inner layer of lesser metal such as silver or brass.  In America, the FTC regulates the labeling of gold filled products.  For example, if the item is 14k gold filled the gold content must be at least 1/20 of the total weight of the item (5%) and can thus be marked, “1/20 14k GF.”

•  “Gold Clad” is a variation on gold filled.  Unlike “Gold Clad” instruments, Powell’s patented Aurumite® consists of a relatively thick layer of gold which can be on the inside or outside of the tubing.  For example, in Powell’s 14k Aurumite the inner layer of gold represents approximately 22% of the tubing weight and is 58.4% gold.  So 58.4% of 22% is about 13%, which is several times more gold than one would typically find in a gold filled product.

•   “Gold Plated” instruments have a microscopically thin layer of gold that is electrically or chemically deposited on a sub-strata of a lesser metal, such as sterling silver or nickel silver.  Plating can be measured in microinches or microns.  1 microinch (0.000001”) = .0254 microns, and the number of karats in gold plating can vary.  The FTC defines “heavy gold plate” as at least 2.5 microns which would be 0.0001.”  By comparison the layer of gold in an Aurumite flute is typically a minimum of 0.003,” which means Aurumite has roughly 30 times more gold than a gold plated flute tube.

 Table 1.  Comparison of Gold Content for 14k

14k Metal                               Gold Index

Solid gold                              58.4

Low karat gold (5k)             20.8

Gold clad                               12.8

Gold filled                             2.9

Gold plated                           0.5

If you want gold in your flute for its acoustical properties related to density, then you should look at instruments which have a higher content of gold.  A solid gold flute will be the most content, followed then by an Aurumite 14k. It is generally agreed that the most important metal to affect the sound is that which comes in contact with the vibrating column of air.  If your primary concern is tarnish or aesthetics, then a plated or clad flute is going to be much more economical.  Keep in mind though, that plating can wear off over time, whereas an Aurumite flute tube with gold on the outside is extremely durable.  Powell Flutes has offered Aurumite flutes for over 25 years and have an excellent track record of quality performance.

9K Aurumite Conservatory - Gold on outside

14K Aurumite Custom - Gold on inside

Aurumite Headjoints - Gold on outside, gold on inside

Gold plated Sonare

Custom Powells in gold - Top to bottom of photo: 9K, 14K, 19.5K

 

Piccolo Headjoints

By Tim Burnett - Powell Flutes Wooden Instrument Manager

It is common enough to say the piccolo is different from the flute and that playing techniques must also differ. But why, essentially, should this be true? There are, of course, obvious physical differences between the instruments: The piccolo is commonly made of wood or a substitute, and most often has a conical bore, rather like many pre-Boehm flutes. These, in themselves, are enough to give the instrument a different response and feel from those of a cylindrical-bore, metal flute. But there still is the basis of tone production, the headjoint. What differences are there, and what choices does a player have?

Close-up on Classic style headjoint.

Traditional piccolo headjoints are essentially cylindrical, or, more properly, several shapes revolved around an axis. The bore is cylindrical (unlike a flute headjoint bore), but, of course, the outside varies in diameter, so that it looks like, well, a piccolo headjoint. Powell Classic piccolo headjoints have a slight swell near the embouchure, giving the head an elegant appearance, and helping a bit to focus the air stream. This feature is sometimes seen on late 18^th century Classical-era flutes and occasionally on instruments from other eras. Despite such refinements, however, the essential headjoint shape remains cylindrical, and the relationship of the embouchure hole to the player's lips is constrained by this fact.

Piccolo specialists often prefer the plain, unadorned embouchure hole of such a head. Many players say they feel they have the best focus and control with a minimalist setup. But, there are also very many flute players, and even serious piccolo players, who prefer something closer to their flute headjoint.

Wave style on the left, Profiled on the right.

For such players, Powell offers two styles of piccolo headjoint in addition to the Classic shape. These are the Profiled, and the Wave. The Profiled features a miniature flute-style lip plate carved from the solid wood of the headjoint. The Wave is a more simple and elegant version of the so-called Reformmundstück often seen on German piccolos.

Classic, Wave, and Profiled styles.

The Profiled piccolo headjoint immediately gives the player more of the feel of a flute. This type of head minimizes the adjustment needed between instruments. Many doublers, especially, say they can put down their flute and pick up their piccolo and instantly feel secure. This head can produce a clear, well-projecting sound with great comfort.

The Wave accomplishes similar things, but with more of the feel of a traditional piccolo. This head also easily produces a clear, well-projecting and articulated sound, with perhaps a little more sweetness to it.

The thing both these heads have in common, however, relates to the geometry of the embouchure hole. The walls of the embouchure must be approximately the same depth or thickness in a traditional piccolo head. There are some refinements possible, but essentially the depth of the embouchure hole is symmetrical, because it is cut approximately into the center of a cylinder.

It is easy to vary the relative heights or thicknesses of the walls of a flute headjoint, however, because the parts are made of metal, and they can be designed and assembled to differing specifications. Thus, it is possible to make flute headjoints with the “front” wall (the side opposite the player’s lips) higher or lower than the “back” wall (the side toward the player).  Many players are accustomed to flute headjoints, such as the Powell Philharmonic-style head, that have a slightly higher front wall. The feel and focus necessary for such flute headjoints is rather different from that of a traditional piccolo head. Because both the Profiled and Wave piccolo headjoints have front walls that are higher than the back walls, these heads retain more of the feel of a flute. For many players, such headjoints offer the best of both the flute and piccolo worlds, without the trouble of the often difficult journey between them.

Wooden Flute Finishing

Since we've spent some time looking at flute finishing, we wondered if the process for finishing a wooden flute differs from that of a metal flute.  We stopped by one of out flute finisher's benches earlier this week, and he happened to be be working on a Handmade Custom grenadilla flute with a sterling silver mechanism.  He said there are not too many differences, but there are a few -- namely polishing and corks.

With a metal flute, the ribs are soldered to the body and cannot be removed, but this is obviously not the case with a wooden flute!  With a wooden flute, the ribs are attached to the body with screws to hold them in place.  In the finisher's role, s/he must remove the ribs from the body and polish them.  After this is complete, the ribs must be reattached.  There are also metal rings on the body that are polished by the finisher as well, but these rings are not removed -- so this polishing process takes extreme care and skill so as not to damage the body. 

Another difference with the wooden flute involves corks -- the most noticeably different being the tenon cork.  Metal flutes do not have tenon corks, so this is an extra step for the finisher.  The flute arrives at his/her bench without this installed, so the finisher must cut, fit, and shape the tenon cork to size and then glue it to the tenon.  There are several other corks on the wooden flute that get some "special" attention -- corks under the arm of the G# lever, under the low D# key, and on the trill keys.  For these keys, a layer of foam is glues to the bottom of the cork (where it would meet the body of the flute).  The purpose of the foam?  Just to keep things quiet since the cork is touching a large surface area of wood on a wooden flute body.

Other than corks and ribs, there really aren't too many differences.  When the wooden flute arrives at the finisher's bench, there is no additional work required on the tone holes (no leveling, etc.).  The bodies and tone holes are finished by our wood specialist.  The processes involved in producing a wooden flute are different but certainly result in a beautiful instrument!

Finishers will add the tenon cork to the body.

Ribs must be removed and polished.  Also in this photo, a piece of the (beige) foam that is attached to corks.

Foam is placed under cork on G# lever arm.

Foam under trill key corks.

Foam under D# key (clearly reflected in the ring!).