Repair Solutions: Pad Modification

Background

Recently at Quinn the Eskimo Brass and Winds, we received a Conn nickel plated bass saxophone to be put into playing condition for subsequent sale. I've worked on a number of Bass saxophones during my time here and curiously - whether this is common to bass saxophones or if it is that Matt has a talent for finding them in this state - the vast majority of the basses we receive happen to be missing their cases when they arrive. As a result, they typically arrive filthy and with a number of big issues. Surprisingly, this particular horn had very few faults with the exception of a bit of cosmetic damage to the plating, and the bell key pads which were far too small for their respective pad cups. Neither of these issues is particularly nasty: refinishing instruments is not something we do, as it negatively affects the instruments value, and we have a range of pads readily available to swap out anything that needs replacing. Unfortunately, being a bass and therefore larger than virtually anything else we typically sell, we lacked the one size necessary to replace the ill-fitted pads that came with the instrument.

Typically, replacing pads is virtually a non-issue; we try to keep a full range in stock so it's a simple matter of finding the correct size, applying glue, and fitting it to the cup. In this case, the missing pad was a simple matter of not having the correct size but some older, larger instruments use pad sizes that are no longer in production by any modern instrument repair supplier. For small-medium sized saxophones (such as altos and tenors) this is, once again, a non-issue since their entire spectrum of pad cup sizes falls into the production range of virtually every pad size available. However, for larger saxophones such as baritones and basses, or less common instruments such as sarrusophones, this can be a problem for certain makes and models since some lower-register keys can utilize pad sizes that are very unique to their specific instruments, especially for manufacturers such as Conn who were particularly known for experimentation.

Many times, it isn't so much a matter of a pad being too big – it’s actually fairly easy to find pads that are bigger than anything found on a baritone or a bass – it's that the pad sizes can sometimes fall into a very specific vacuum between 70mm and 74mm that seems to exist in the inventory of every single pad supplier. It should be noted that it's not unreasonable that suppliers don't carry these particular pads: there simply aren't enough instruments that use these pad sizes to make carrying them commercially viable. Carrying that burden is not something that should be expected of the modern supplier on the off-chance that a technician is going to do an overhaul on a very specific vintage of a certain type of saxophone. On the other hand, this does not change the fact that the only commercially available solution is to install a pad that is very noticeably smaller than the pad cup. While technically functional to some extent, as long as it can be made to seal, this is unacceptable for a number of reasons. Aesthetic issues aside, an ill fitting pad can make adjusting much more difficult and time consuming, and may potentially damage the lasting potential of the instrument as it exposes more of the pad, and introduces more variables that may affect how the pad seals over time. Whether a pad is not commercially available, or simply not on hand and there is not enough time to wait for it to arrive in shop (as was the case with the aforementioned Conn bass) sometimes the only solution is to modify an existing pad to fit your needs.

Process

When modifying a pad to fit an odd key size, the first step is to pick a pad size that is noticeably bigger than the pad that is needed. In the case of the Conn bass, the two bell keys both required pad sizes of 68mm; luckily, I had a selection of larger pads left over from a past job. The process involves peeling the leather skin from the felt body, so once the pads were selected, I removed the resonators to make this possible.

The only portion of the leather skin that is physically attached to the body of the pad is the thin ring that lines the perimeter of the cardboard backing. Using a modified dental pick, I carefully peeled back the leather, being careful not to tear anything. It's important to keep in mind that the glue isn't particularly strong and readily separates with assistance, and therefore is better to be pried apart with a blunt instrument rather than cut away with a blade which could easily cut the leather and damage the working surface.

In order to correctly size the new pad, the felt needed to be cut to a perfect circle at the exact diameter of the key cup. Cutting a circle is not particularly difficult if you can mark it with a stencil, but unfortunately the chances of finding a stencil the exact size of any given key cup are incredibly slim. Using the key cup itself would only give the outside diameter of the cup, therefore neglecting the thickness of the metal lip and resulting in a pad that is too big to fit into the cup. As a solution, I marked the rim of the key cup with a heavy application from a sharpie, which does not effectively stick to metal surfaces and can be easily cleaned with alcohol or another solvent when the cutting process is finished.

Once the sharpie was applied to the rim of the key cup, I centered the key face down on the naked felt and firmly pressed the key into the surface, rotating the key side to side while keeping a firm application of pressure and making sure it stayed centered. As previously mentioned, Sharpie does not readily stick to metal and as a result, the felt readily absorbed the black ink and left a perfect reproduction of the size and shape of the key cup.

Given that the newly formed black line is a 1-1 representation of the key cup, cutting around the inside of the line reduced the felt to the correct diameter.

Gluing the entire surface of the leather to the felt could potentially cause issues in pad sealing, so in order to protect against that scenario, the only glue I added was to the outer rim of the leather, attaching it to the side, and cardboard backing of the felt. First, in order to accurately determine what section of leather on which to apply the glue, I centered the felt on the leather, and traced the felt with a pencil.

Being careful to utilize the boundaries made by the felt, I applied contact cement to the outer ring of the leather, as well as the sides and cardboard backing of the felt. Once the glue dried enough to become tacky on both surfaces, I laid the felt face down on the leather, and pressed the leather upwards so that initially, only the sides of the pad were attached.

Since the leather on the back of the pad forms a ring, simply folding the leather over and gluing it to the cardboard backing would have forced the leather inwards on all sides, inevitably creating areas that would have bound, affecting the geometry of the pad and making it difficult to seal. In order to avoid this, as I folded the leather over, I periodically made incisions along the leather which freed up the surface to lay flat over itself, rather than bunching up.

With the leather successfully glued to the felt, the pad was finished and all that was left was to install flat metal resonators to match the rest of the horn and finish the process.