Author: Gordon (NZ)
Date: 2006-08-26 22:30
Clarnibass. I am highly impressed with your understanding, as a budding DIY repairer, of the issues and compromises that need considering in this job.
Vytas wrote, "Without these vintage big bore instruments stepped pads would be obsolete. "
Let us assume that a stepped pad is chosen so that it can be fitted with the felt slightly covering the edge of the key cup....
A stepped pad, no matter what the material, can have advantages, including:
1. It has a larger diameter, which is desirable fur situations already mentioned. Vytas, I guess you work only on professional instruments. In the 124+ brands of clarinets i.e. hundreds of different models) I have worked on, there have been MANY where misalignment of the three lowest keys (i.e. key cup arms too long or two short, for an appropriate thickness of pad to seal centrally) has been evident. It is also common on other keys.
2. The key cup edge gives additional support to the felt at the edge of the pad (depending on how the pad is installed). This could be likened to some degree to the extra springing given to the edge of a mattress, that makes the mattress more functional closer to the edge. In many situations, this is desirable also for a pad.
A stepped pad, no matter what the material, can have disadvantages, including:
1. The larger diameter can reduce venting in CERTAIN situations. A notable one is when the F# tone hole face is set very deeply.
2. It is more important to choose a pad with an appropriate thickness of felt, because the felt will always project beyond the key cup.
There are additional issues associated with the choice of MATERIAL of the pad, all of which have been well covered in other threads.
In view of all of the above, by far the majority of manufacturers AND technicians are still finding bladder pads the most appropriate choice for by far the majority of instruments. This vast majority of makers and technicians are not stupid. Many of us carefully analyse the options, fully aware of the advantages and disadvantages of each choice, and chose according to the situation, rather than showing obstinate single-mindedness. The choice is still, much more often than not, stepped bladder pads for clarinets. (Oboes, flutes, saxes are different.) However as I said before, eventually a solid polymer pad is certain to make bladder pads obsolete. It may well make cork pads obsolete too. Kraus's "omnipad" COULD be the model that heralds this change. Cork is already almost obsolete for most applications to keys and linkages (but certainly not for tenons).
Clarnibass, I respect you for taking this road of considering each situation on its merits; I believe it is vital when dealing with the huge spectrum of different brands and models out there, especially when the vast majority of customers have budgetary constraints. IN this issue, and the way you dealt with the bass clarinet vent issue, I think you have the makings of a top-rank technician of the future.
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The Clarinet BBoard
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