Building the White Gold Flute - Part 7

In our last post, we followed the white gold white flute into the polishing room, where we had a chance to see Alex and Galina. Galina was the finisher for this flute, so after the polishing was done, we spent time with her at her bench.  In the video below, you will see one of many steps in the finishing process -- hand shaping corks.

The finisher plays an important part in the process of bringing the flute to its finished, playable stage. We've written a two-part overview of their role in previous posts which you can read by clicking here for part 1 and here for part 2.  We've also written about many other parts of the finisher's role, including leveling keys and tone holes, undercutting tone holes, fitting keys, installing springs, and fitting the headjoint and footjoint.  One of the central parts to finishing the mechanism is padding and shimming, which you will see in the video below.

The photo below shows the flute as it looked after Galina finished it.  You'll notice that the blue protective tape is still on the keys. This is because the flute was on its way to testers for play-ins and play testing, and the tape protects the keys from any cosmetic damage during those processes.  If the testers find that the flute needs additional adjustments, it goes back to the finisher for the adjustments to be made.

Finally, a flute would certainly not be playable without a headjoint, so we met with JoJo as she brazed the riser and lip plate onto the headjoint and cut the headjoint to length, as you will see in the video below.  After this, the headjoint is sent to a "headjoint cutter," who is the person who hand cuts the headjoint to the shape and specs of the headjoint style (Signature, Soloist, Philharmonic, or Venti).

Music Credit:
Powell Artist Joshua Smith
Robert Schumann  - 3 Romances, Op.94: Nicht schnell 

Building the White Gold Flute - Part 2

We're in week 2 of our white gold NFA Custom flute's journey to being completed.  When we last saw the flute, it was in raw material form -- body tubes and components in the body and stringing kits.  As the body and stringing kits were being assembled in the materials department, the body tubes (center and footjoint), were sent over to Powell production team member Jason Sherman.  Jason's role is to drill very small holes in the tubes.  Each hole is the center of what will actually be the full tone hole.  As with the entire process, accuracy is key.  In order to drill these holes precisely, Jason programs a CNC (Computer Numeric Control) to drill the holes into their exact locations on the tubes, as you will see in the video below.  He repositions the tubes a few times during the process to drill offset holes as well as holes on the side and back of the tubes.

Footjoint after initial holes were drilled.

After the holes are drilled, the body tubes go back to the materials department and are placed in the body kit.  The body kit is then picked up by the body maker, Alex Shtyrkov.  We spent a few days with Alex as he prepared each and every tone hole to be brazed to the body.  Before the tone holes are brazed on to the body, they must be prepared to fit the tubes exactly.  Alex goes through each tone hole, fitting them and shaping them by hand.  Once they are ready, he attaches them to the body to prepare for brazing.  The tone holes must be secured so that they do not move during the brazing process.  Securing the tone holes requires the use of small fixtures that go through the initial center holes that were drilled by Jason.  Alex secures each tone hole, and then prepares them for brazing, which we will see next week...

Why Solder Matters

By Steven Wasser - President, Verne Q. Powell Flutes, Inc.

These are photos of two sterling silver pieces which have been joined using two different techniques.  The photos were done at MIT using an electron microscope.

The top portion of the photo to the right shows a joint that has been made using high temperature silver braze at around 1400°F.  The bottom portion of the photo shows a joint that has been made using low temperature solder at around 450°F.

Does this affect sound?  Yes!  The high temperature silver braze inter-diffuses into the sterling silver, and the result is a piece of metal that acts as if it were a single piece of metal.  The low temperature solder acts more as metal glue and sits in between the two layers of metal.  In my experience vibration and resonance are superior when only a single, homogenous metal is involved.  With the low temperature joint the solder layer can act as a barrier to the transmission of vibration and can dampen response.

What about strength or durability?  With a silver brazed joint the musician should never have to worry about things like tone holes leaking or lip plates falling off flute headjoints.  The strength of a joint that has been done using low temperature solder is typically 5000 lb/sq inch.  The strength of a silver brazed joint is 40,000 lb/sq inch, 8x stronger!

Silver brazing is much more difficult to perform than low temperature soldering due to the high temperatures involved.  Also silver brazes contain more precious metal than most low temperature solders and are usually more expensive. For flutes, we silver braze our tone holes,  We also silver braze the headjoint lip plate to the wall and the wall to the headjoint tube.