Clarinet Disassembly

I'm posting these lecture notes for the convenience of the NYCDOE Band directors attending a seminar on woodwind maintenance.

These are my lecture notes from a clarinet maintenance class I used to give at MSM. It quickly outlines disassembly and reassembly and some basic solutions to problems you might be able to work out for yourself.

MSM Repair Seminar 2014

Mechanics of the instrument: Terminology

pivots and rods

-Pivot screws are the small pointed screws at each end of the key. Most of the lower joint keys are held on by pivot screws.

-Rods are the cylindrical, smooth screws that span the entire distance from post to post. Top joint is mostly held together using rods.

flat springs and round springs

-Flat springs are found on the register key, side trills, and throat A key. One end is attached to the key and the other contacts the body of the instrument.

-Round springs most often protrude from posts and need to be secured behind a “catch” at the opposite end.

closed keys and open keys

-Closed keys are keys that are sprung with the pad touching the tonehole. The key movement opens the key. Closed keys need to have sufficient spring tension for the pad to seal securely against the tonehole.

-Open keys are sprung with the pad sitting away from the tonehole, and the key action brings the pad down to the tonehole. Open keys need only be sprung heavily enough to raise the weight of the key itself. A heavier spring tension can improve key response speed, but too much tension is tiring to the hands.

binding and free

A key is considered to be binding if it doesn’t move completely freely when assembled without spring tension. A bind can be caused by wood shrinkage, causing the space between the posts to be too short for the key. It can also be caused by corrosion, congealed oil, or a bend in the rod or key. A key is free when it falls of its own accord when assembled without spring.

Mechanical Disassembly:

Tools of the trade:

1- Screwdrivers- Use the largest screwdriver you have that will fit in the screw slot. Screwdrivers that are too small can mar the screw slot.

2- Pliers- Use only smooth jawed pliers, and be gentle. Pliers should only be used to remove rods, never to bend keys. Grip the rods with the plier jaws at each edge of the screw slot to avoid squeezing the screw slot closed.

-Rods: unscrew until you hear/feel a click, gently remove with pliers, wipe off oil on paper towel, and immediately place back into key.

-Pivots: replace in post when not assembled.

Never leave pivots or rods on a table, they may get mixed up. Although they look similar, pivots and rods are not interchangeable.

Only work on one section at a time. Fewer disassembled parts=less confusion. Don’t clean the oil off the rods with tissue or toilet paper, it’s too linty. Use a paper towel, washcloth, or old tshirt.

Reassembly:

As you reassemble the instrument, make sure all the parts are clean. Position the key on the body of the instrument and add a small bead of oil inside the post at the rod entry point. For keys held on by pivot screws, add a bit of oil at each end of the key. Line up the rod or pivot screw by hand, then pick up the screwdriver and gently tighten. If it feels like it is being forced, remove it and try again.

Rods should be tightened until they stop. Do not overtighten.

Buffet pivot screws for instruments 15 years old and younger have an orange or black plastic ring that permits it to sit in the post in a variety of positions. When reassembling the key, tighten the pivot screws until the key binds slightly, then back off a bit until the key is free. Try to keep the pivot screws at either end more or less even.

Selmer pivot screws, older Buffet pivot screws, and most bass clarinet screws don’t have this plastic sleeve and should be tightened in the post until they stop.

Engage each round spring as the key is being assembled. Be careful not to overextend springs or you might change their tension. Try to handle round springs as little as possible, and use a spring hook or crochet hook.

As you reassemble, be sure the tip of flat springs make contact with the metal plate on the body. This is especially tricky with the side trill keys.

Order of operations to reassemble top joint:

sliver D#/A#
C#/G#
Thumb ring and index ring key
D/A ring key
Throat A, then Throat G#
Top 3 side trill keys all at once
Side Bb/Eb
Register key

Order of operations to reassemble lower joint:

LH C key
F#/C# (tricky spring! Use spring hook.)
E/B
F/C, then Ab/Eb
Right hand sliver key
Right hand rings
Left hand pinky spatulas

Common problems and simple solutions:

Joint Assembly: Tenon Corks:

Tenon corks should have friction through the entire width of the cork and should fit firmly but not tightly. Tenon corks are a gasket, meaning that they create a seal between the two parts. Cork is not airtight on its own, it needs cork grease to make a complete seal.

If your tenon cork has friction through the entire width but the joints still do not fit together well, you may need to fit the tenons. Brush a light coating of nail polish on the wood part of the female tenon (the part with the cork), both above and below the cork gasket. Be sure to go all the way around, and try not to get the nail polish into the corner where the tenon meets the body.

It may take several layers to do the job properly. Let each coating dry for a few hours before adding the next coat. If you rush it you’ll end up with a gooey mess.

If you go too far, either sand the spot lightly or use nail polish remover or acetone to remove the excess.

The best way to tighten loose tenon corks until you can get to the repair shop is with Teflon plumbers tape. One or two times around should do it. If you don’t get to the repair shop you may need to keep adding more and more as each layer compresses. Dental floss also works (preferably the waxed old school string kind), as does electrical tape.

Throat G#/A Key Adjustment:

Poor adjustment of the throat G#/A can cause the G# key to remain open even when it is in the closed position. When pressing the A key, there should be a minute amount of movement before the G# begins to come up. If you aren’t sure if there is enough play, raise the G# key, put a cigarette paper feeler under the adjusting screw, and pull out the paper, feeling for friction. If there is friction on the paper, turn the screw a minute amount (one minute if it were the minute hand of a clock) and repeat with the feeler gauge.

Bridge key adjustment:

The “1 and 1” Bb bridge key adjustment is important but is also the moodiest adjustment on the clarinet. Too loose and this fingering for Bb is ineffective, too tight and the right hand ring key pad won’t close. Your center tenon must fit perfectly in order for the 1 and 1 fingering to be reliable.

Symptom: 1+1 Bb not working,

-Try twisting the tenon slightly to change the bridge key contact point. Still not working? Add a piece of tape to the bridge key cork.

Symptom: 1+1 Bb working, but slight movement is felt in LH ring key

-Try twisting the tenon slightly to change the bridge key contact point. Still not working? Use a razorblade to shave a paper thin amount off the bridge key bumper cork.

Symptom: Bb working, nothing in right hand working

-Identify that this is a bridge key problem by twisting the tenons so the bridge key is no longer engaged. If the instrument works again, then you have a bridge key problem. Use a razorblade to shave the bridge key bumper cork until the right hand rings will close again.

Crow’s Foot Adjustment

Symptom: Long B won’t play without the C being held down also

Add a piece of scotch tape to the right side of the Crow’s Foot (arm under the RH E/B touchpiece that is the shape of a pizza with one slice removed). Depress LH B key, test B and C keys with cigarette paper feeler, continue adding scotch tape in layers until they are as even as possible.

Symptom: Long B won’t play at all, adding the C doesn’t help

Solution: Shave a paper thin piece of the crows foot bumper cork. Depressing LH B key lever, feel B and C pads with cigarette paper. Continue until they are as even as possible.

Binding Keys:

If a key won’t move freely of its own accord or has a sluggish, scratchy feeling as it moves, first figure out whether the key is held in by a rod or a pivot screw.

If it is held by a rod, remove the rod, clean and oil, and replace. If it still binds, try loosening the rod ¼ turn. Be sure to tell your repairperson at your next appointment. Keys held by a rod that are the most likely to bind are the throat A and top joint index finger rings.

If it is held by pivot screws, try loosening the pivot screws ¼ turn, one side at a time. The keys with pivot screws that bind the most are the left hand C, right hand rings, and E/B key.

Sadly, you can’t expect to be able to fix binding keys yourself every time. Sometimes they require shortening of the key, which should only be done in the repair shop. Let your repairperson know your instrument is binding, it is a repair that typically doesn’t take very long.

Tuning:

Many clarinetists attempt to change the tuning of particular notes on their instruments. Tuning is achieved by changing the dimensions of a specific tonehole.

When considering making a tuning adjustment, remember that any adjustment you make will affect all notes with the same fingering. Upper register fingerings will be affected by tuning adjustments more than lower joint adjustments.

Logically, adding material to a tonehole reduces its size, thereby lowering the pitch. You should only work on adjusting sharp notes to be flatter. Raising the pitch of a flat note requires enlargement of a tone hole and should only be done by a competent repair person.

Remember that a note speaks primarily out of the first open tonehole, not the hole covered by your finger! For example, to lower the thumb F/C note, you would need to add material to the LH index finger chimney.

When adding material to a tonehole, be sure the material is trimmed properly so it doesn’t protrude into the bore or stick out over the edge of the tonehole. Add material only to the top half of the tone hole (closest to the mouthpiece). This effectively moves the tonehole down the bore slightly, with the least amount of dulling of the note. If the note is both sharp and very bright you can try adding a thin layer of material all the way around the tonehole.

In order to do tuning work you have to be comfortable with disassembling and reassembling the instrument. I recommend using materials that are self sticking and that can be easily removed for tuning, such as electrical tape (layered several times as needed) or new mouthpiece patches. Clear nail polish works well and is more permanent than tape, but you have to have the time and patience to do several layers without rushing. Gooey nail polish will ruin a pad in an instant, so if you go this route don’t rush it.

Emergencies:

Every now and then we will all be in a place where we have an urgent problem and nobody is available to help us. Here are a few tricks to help:

Bumper cork fell off, key is noisy

If you still have the bumper cork, reattach it using a gel super glue. If you don’t have it, or can’t glue it, trim a green furniture velvet to the proper size and use the self stick glue to stick it to the the key or to the body. Layer if necessary to achieve proper thickness.

Broken Springs:

Broken springs can usually be temporarily remedied by judicious placement of a rubber band. Be sure to consider whether the spring needs to be sprung open or closed. Remember to use other posts as an anchoring point if necessary. Don’t keep rubber bands inside your case compartment, the sulfur in the rubber corrodes the keys. For the same reason, don’t leave a rubber band on your instrument for an extended amount of time.

Torn Skin pad:

Wrap a single layer of Teflon tape around the pad and tie in a neat knot on top of the pad cup. Trim the tails completely. If no Teflon tape is available, use a strip of Saran wrap.

Pad Fell Out (but you still have it!)

Replace the pad in the pad cup, attempting to get it back in it’s original position. Use a safety pin if you have to to turn it in the cup. Tie a single layer of Teflon tape around the pad and knot on top of the key cup, using the same procedure as a torn skin pad.

Pad Fell Out (and is lost forever!)

Roll a bit of poster tack or chewing gum in your fingers to make a ball the size of a pea (for top joint pads) or a bit larger for lower joint pads. Place into the pad cup and wrap with a layer of Teflon tape or saran wrap, knot it neatly on the top of the pad cup and trim the tail. Press the key snugly against the tone hole so the poster tack can take the shape of the tone hole.

Horn fell over and keys are bent!

If the instrument still plays, leave it as it is! It’s possible you might make a bigger mess if you try to straighten it out. If it doesn’t play at all and you want to try to straighten keys, use only your bare hands to move the metal back to its original position. You don’t own the proper pliers to use for this purpose, trust me, and you’ll only make it worse by trying. Eyeball key placement, if it looks right, it probably is.

Oh no, it’s cracked!

Repair people don’t like you to repair your own cracks because our materials are always stronger and work better than what you would have on hand. If at all possible, leave the crack alone. It may be leaking, and play it if you have to. If it is absolutely necessary, glue the crack with Krazy Glue but for heavens sake don’t glue the pad to the tonehole. Remember, the glue will run along the crack by capillary action, so take the key off first, or at least wedge the pad open. Use just a thin layer of glue. A heavier dose of glue does not increase the strength of the job.

Do NOT put cork grease, beeswax, or anything oily into a crack. It will prevent the proper glue from sticking later on.

Remember, cracks are a rite of passage for woodwind players, and usually are a minor inconvenience other than the rather steep repair bill.

Clarinet Disassembly

Mechanical Disassembly:

Reassembly:

Emergencies:

Featured Posts

Recent Posts

Archive

Search By Tags

Follow Us