The neck cork is one of the more critical, but often overlooked parts of the saxophone. Frequently players will suspect poor pad coverage or adjustment problems when the real culprit is an improperly fitted neck cork. If the cork does not fit the mouthpiece correctly, there may be a small gap at the end of the neck. This gap can cause poor response and "warbling" in the low register. The mouthpiece should fit snugly in all positions on the neck and should not wobble when pulled. If it does, the neck cork is too small at the end of the neck and it needs to be replaced. Of course, if the cork is chipped or loose it also should be replaced.
The first step to proper replacement is the safe and complete removal of the old cork and adhesive. There are several ways to remove the cork and each of them has its' advantages and disadvantages. One of the safest is to scrape or peel the cork off to expose the adhesive used to hold the cork. Just remember to scrape toward the end of the neck so as to avoid scratching the neck. Once you have exposed the adhesive, you need to clean off all of it to obtain the best bond possible. You do not want the cork coming off when you pull off the mouthpiece.
Depending upon the adhesive used, you need to use a solvent to remove it. Alcohol works well where the adhesive was shellac based, but I prefer to use MEK. It removes contact-type adhesives as well as shellac. You need to avoid contact with the rest of the neck as MEK will dissolve some lacquer finishes. Once the adhesive has been completely removed you are ready to proceed.
Measure the distance from where the old cork was to the end of the neck. Cut a piece of 1/16th inch sheet cork about an eighth of an inch longer than you need. On one of the narrower edges, cut a bevel of about 45 degrees. This will be used to create the lap when you put the cork on the neck.
Depending on the character of the cork, it may be best to flex the cork and maybe even "pound the pith" out of the cork so it will bend around the neck without breaking. Once the cork is softened, you should spread a thin coat of contact cement on both the neck and the cork. When you glue up the cork, you need to apply glue to the side of the cork that will be placed against the neck, and also on the beveled edge that you cut for the lap. After the glue has dried tack-free (usually just a couple of minutes) you are ready to put the cork on the neck. Holding the neck vertically in front of you, estimate how much cork it will take to put the lapped edges on the underside of the neck. Now starting from the center of the neck, press the cork against the neck making certain that the bottom of the cork is perpendicular to the centerline of the neck.
Placing the lap on the left side allows you to turn the cork in the lathe and have the lap not pull up. Starting on the side with the lap, press the cork firmly onto the neck so that the cork follows the angle of the neck. Once that half of the cork has been glued to the neck, you press the edge of the cork that has been cut for the lap firmly onto the neck. The best way to do this is to wipe off your thumb so as not to contaminate the glue with oils and press down along the edge. Now wrap the other half of the cork down onto the neck. The cork will go down at an angle and may become uneven. As long as the cork still overlaps the top of the neck and is tight, it will be fine. You will make it look right in a moment. Now cut off the remaining cork at the lap. Cut this as close to the surface as you can without gouging the cork. Trim the excess material from the end of the neck, and make the bottom end of the cork straight by squaring the cut at the lap if necessary.
Now we need to fit the cork to the mouthpiece. Place the neck onto the lathe using a sax neck mandrel to hold the neck. This is an expansion-type mandrel that allows you to spin the neck in the lathe. With the lap facing up, sand the lap as little as necessary to make the surface level. Now you may turn on the lathe and spin the neck. With the neck spinning, use emery cloth strips to square off the end of the cork so it is flush with the end of the neck (A very slight bevel on the edge is acceptable, but too much will introduce an unwanted gap.) The object at this point is to make the neck cork taper the same as the mouthpiece. This usually means removing a little material from the end of the neck and cutting down the cork further up the neck so the mouthpiece will go on correctly and without the gap mentioned earlier. Remember that what you want is to achieve a fit with the mouthpiece that allows you to have the mouthpiece pulled out and still not rock or wobble. Once you have the cork cut down enough, it's time for the final fit. What we want to do here is to make the cork and mouthpiece tapers fit exactly.
Using a hair dryer and with the neck spinning in lathe, melt some paraffin wax onto the cork. The best way to do this is to place the bar of wax against the cork and heat it while trying to force the wax into the pores. Once you have the cork waxed, remove it from the lathe, remove the mandrel, and quickly (while the wax is still warm) press the mouthpiece onto the neck so as to have the waxed cork conform to the mouthpiece. Let it cool. After the cork has cooled, you may remove the mouthpiece and any loose wax. Apply a very small amount of cork grease to the cork, and you will find that the mouthpiece fits the neck perfectly whether pushed in all the way, or pulled out all the way.
Some other points to consider:
1. On some of the finest saxophones there is a metal ferrule at the end of the neck. While this does help protect the neck should it drop, it can also cause a problem by creating a gap at the mouthpiece. While some technicians prefer to cork up to the ferrule, I prefer to cork all the way to the end of the neck, even if it means removing the ferrule from the neck. I find that the instrument's response is much improved.
2. If the player must use different mouthpieces on a regular basis, you may want to forgo the waxing and use a softer cork so the cork will rebound easier when the mouthpiece is removed and will fit both mouthpieces better.
3. Bundy saxophones recork well with 3/64th inch cork. Cut off and smooth the lap, wax the cork and put on the mouthpiece. Done. Very little if any adjustment is necessary