Monday, September 24, 2012

First Customer horn: Clarinet Repad

We recently began repads on Music & Arts rental fleet. They were all in relativity good condition. Mine was missing a few foot corks and had two bent keys. The first thing I addressed was those bent keys. The keys were repaired by simply flexing them back in to position and by( for lack of a more eloquent word) hitting them with a soft hammer. Once all of the keys were in working order, I began the disassembly.

After the all of the keys were off, I continued by removing all of the corks and pads. The pads were removed using a torch and the corks, with a razor blade.
 At this point I cleaned the bodies, keys and pivot screws and hinge rods. The body with simple dawn dish soap and water, The keys in a pickle bath, and the hinge rods with denatured alcohol and a mild abrasive fabric.

Now The fun begins- Key fitting.

Key fitting is the removal of unwanted play in a key and also making sure that there are no binds in a keys motion. Motion can be found on the ends of hinge tubes(end play) and laterally across a key(lateral play or lat play).  To fit keys I used swedging pliers and collets. They, effectively, shrink hinge tubes, and by displacing material lengthen them as well.
Here is a picture of a key being swedged with the collet tool. Please note that this was not off of the clarinet that was being repadded.

After all the keys were fit I buffed the keys to remove any minor marring and tarnish created by the cleaning and the fitting.

Before:

And after padding(which I will explain next):

Padding Involves selecting the right size pad, applying the correct amount of glue and seating the pad. So for ,say, a C trill key, one would choose a 10mm or possibly a 9.5mm pad, depending on the size of the key. This varies between makes and models. Then, one would apply enough glue to completely fill the pad cup with the pad fully seated. Too little and the pad will not be able to float, to much and it will all ooze out. To seat a pad one "floats" a pad to the position where the pad completely covers the tone hole. The contact should happen simultaneously all around the tone hole.

Finally, after the daunting task of padding the instrument, I began corking keys. The corking does several things. For-most, it silences the keys by providing padding between them and the body. Secondly, it, along with the pads, controls the venting, or how far a pad opens. Lastly it is ivolved with regulation and articulation between keys. 

Now, while it is referred to as corking, cork is no longer the only material used. Cork has been the industry standard for, well, a long time. However other materials have been and are used. The most common of these, at least in our shop are tekcork/gummikork, synthetic cork, and Teflon. Each has its advantages and disadvantages. I will not go into them now.

Anyways, Here are some images of corking. Notice the rough cut, trimming, and fitting of the cork.








I continued corking until all the keys were vented and regulated properly. I will continue to keep you up to date with my progress.