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Maintenance & Care

Crack Repair for Piccolos and Wooden Flutes

A crack in a piccolo or wooden flute is the opening or separating of the wood fibers. Cracks always follow the natural direction of the wood grain, that is, from top to bottom. A crack looks like wood grain that has opened or is separated. Most cracks in piccolos originate from the bottom of the headjoint and travel up to the embouchure hole. Cracks can also originate from a post or a tonehole.

Temperature change and moisture loss are the two leading causes of cracking. Grenadilla wood fiber consists of wood cells linked end to end. These cells lose their moisture from the sides, not the ends. This means that the change in the wood is lateral, either expansion or contraction. If the circumference of the piccolo shrinks, the headjoint can very likely crack at the socket end where the body goes in. This area usually has a metal insert that the grenadilla wood surrounds. Since the metal changes at a different rate than the wood, the wood relieves itself by cracking.

This is not the end of the world - just money! There are two procedures which will restore your instrument back to playing as before. One is pinning, and the other is a newer procedure called graphite banding.

Pinning has been around for a long time. To pin you need:

  • a #54 drill rod threaded to 0-80
  • a #55 drill
  • a bench motor
  • a jeweler's saw
  • a small file
  • a flexible shaft tool
  • some leather

First lay out the pin placement. I locate the end of the crack and with a pencil, lay out a pin route anywhere from 1/4 to 1/2 inch beyond the end of the crack. That will be where my first pin will be. Then measure every 1/2 inch and mark for your next pin. Continue marking for pins for the length of the crack. Once marked, drill for the pins. I like to angle the pins so they are not exactly 180 degrees to the body of the instrument. For instance I'll put the first one in at about 160 degrees, the next at about 200 degrees, the next at 160 and so on.

To drill, start 1/2 inch to 5/8 inch from the crack. With my flexible shaft drill in one hand and the joint in the other, I begin to drill. Start at 90 degrees to the body for the first 32nd, then roll to the proper line for going through only the wall. As you drill you will often be able to feel when the bit reaches the crack. Continue drilling and watch for a ring of heat percolated oil to appear at the other end. When drilling for a pin that will show on both ends this tells you that you are almost through. For blind pinning stop! (Blind pinning refers to the far end of the pin not showing.) Withdraw the bit. Measure the length of the hole with your bit. Mark the threaded pinning rod now placed in your bench motor 4 threads shorter than your hole length. Cut a notch a third of the way through the wire. Now run the pin in by hand until the notch reaches the surface. Turn the chuck 3 1/2 turns by hand. The notch is now down. With a quick snap of the joint towards you, the pin will break off below the surface. Repeat for each pin. To finish and hide your pins you will need an old 78 record and a wood burning pencil. I use two different records. I have a blue label Don't Bury Me On The Lone Prairie for professional and a green label Yippy-I-Ty-Ye for students. Simply entertainment. Plug in the pencil while getting organized. Warm the hole with the point of the pencil and gently shave some melting record in. Tamp it. Push it in with your thumb. It's not that hot. Build up to slightly higher than the surface. To finish, start with the 6 inch file and lightly bring the filler down to the surface. Sand the file marks out with 400 grit sandpaper. Lastly, I use a thin strap of leather with buffing compound. Shoeshine it till you get the level of sheen you want. As for filling the crack itself, black crayon melted in with a fine spatula on the average crack will seal it. Wax has good elastic properties allowing it to move with the wood. For the grand finale, rub a little natural oil over the surface.

The second procedure is graphite banding. I feel this is a wonderful discovery. The procedure starts with mounting the headjoint in the lathe. Cut a track .030 of an inch deep, the length required, without touching the embouchure hole or tenon ring. Mix up some 45 minute epoxy. Latex gloves come in really handy at this time. Pull the graphite through the epoxy. Begin to wrap it clockwise into the crack. Clockwise is advantageous so when you are machining it down, the lathe bit does not grab and tear it out. Wrap tightly but do not squeeze out all the epoxy. This shrinks a little, so go a little higher than the surface. Let it dry overnight. Machine down to the surface. Next use a three cornered file, 400 grit silicone carbide paper, followed by 600 grit or 1800 grit Micro-Mesh. I again finish with the leather and lastly, natural oil.

Graphite banding has been the most supportive repair for piccolo cracks that I have found to date. I get my graphite banding threads from J.L. Smith in Charlotte, NC, USA.

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