First, carefully remove the old cork from the tenon. This should be
scraped off without damaging the tenon itself. Remove the glue residue
with an appropriate solvent. Keep alcohol away from plastic
clarinets. Alcohol will cause plastic clarinet bodies to crack and
craze. A safe solvent to use is Mineral Spirits. It will remove most
contact -type cements.
Once the tenon is cleaned, you need to measure the width of the slot in
the tenon so you can cut your cork. This done, put a coat of contact
cement on the tenon and set it aside.
We need to make the cork with a slight bevel to fit into the cork slot
tightly. The best way to do this is to use a metal ruler as a straightedge
and cut off a small amount of the sheet cork by placing your cork knife
or single edged razor blade at an angle, (down and to the left), and
drawing the blade the full width of the cork. This will give you one
beveled edge to work from. Now turn the cork over so the beveled
edge is facing up and on the right hand side. Measuring from the
inside/top edge of the bevel, mark the width of your cork slot at both
the top and bottom of the cork. I like to use the back side of my cork
knife to press a mark into the cork, but any thin mark will do You
should now have the bevel on the right, and 2 marks on the cork to the
left. Place your ruler on the marks, and cut the cork so as to cut the
second beveled edge, again down and to the left. You should now have
a strip of cork which the narrower bottom side will fit your tenon nicely.
Remember, the beveled edge goes down into the slot. The left over
material on top will be removed shortly.
The final preparatory cut is to cut the bevel for the lap joint. With the
beveled side of your tenon cork facing up and horizontally placed in
front of you, cut a bevel on the right hand end of the cork; again down
and to the left. This bevel will be used to form a lap joint that will be
smooth and strong. With the cork still in this position, horizontal, with
end-lap on the right, apply an even, thin coat of glue to the cork. Now
turn the cork over, and apply glue to the lap joint bevel on the other
side of the cork. Let the glue dry.
Now we must install the cork onto the instrument. What we want to
accomplish is to have the lap joint wind up on the back side of the
instrument, i.e., the side of the instrument opposite the label.
Holding the instrument in front of you with the glued tenon up and the
side of the instrument with the label facing you, place the cork onto the
slot so that the lap-joint bevel is on your left and hanging over the side
about 1 inch.. Apply the cork with such light pressure that the cork may
even fall off under its own weight. Do not press the cork down into the
slot yet. Now is the time to check that the cork is straight in the slot and
perpendicular to the bore of the instrument.
When you are certain that the cork is in the correct place, press the
cork firmly into the slot. Start at the middle, and work to the left,
towards the lap joint. Work a little at a time and keep the cork straight
in the slot. When you reach the lap joint, wipe off your thumb to
remove any oil, and carefully press the bevel firmly into the slot. Now
go back to the middle of the cork strip again and work to the right until
you come to the lap. Press the cork into the lap bevel tightly so as to
avoid any gaps under the cork. Cut the leftover cork strip even with the
lap joint.
Now comes the final shaping. Place the tenon against a bench peg, or
on a drumstick or dowel rod held in a vise and covered with a loose
piece of cloth. Note: Make certain that the cloth does not crawl
up into the bore of the instrument. Keep some in sight at all
times so as not to get it stuck in the bore. Using a ½ inch wide strip
of 220 grit emery cloth about 6 inches long, , sand the lap joint on the
cork smooth. To cut the cork down on the edges, care must be taken
so as not to sand any of the tenon itself. Do not let the abrasive
touch the tenon! Bevel or round the leading edge of the tenon cork
more than the inside edge. The bevel will help start the tenon into the
socket. You need to remove enough material from the cork so the joint
goes about halfway together without grease. Once you have reached
this point, grease or wax the joint. Try the fit. It should be tight and firm,
without rocking. If the cork is on correctly and the joint wobbles, then
the tenon needs professional care. Have it sleeved, replaced or
somehow repaired by a tech that you trust. It is possible to cork the
tenons fully to remove the wobble, but this can be tricky. Remember,
new tenon corks like cork grease. Be gentle.