Wednesday, June 5, 2013

Lesson Learned - 6/4/13

I'm starting to get a better understanding of how pads age and how the behave as they get older. A skin pad - like a clarinet pad - that seals firmly around the entire diameter of a tone hole would be expected to seal. But if it's an old pad, it can leak even though there are no obvious leaks around the perimeter. In the past I've discovered this to be the case with pads that have tiny holes in the skin or cracks in the skin. Sometimes on flute pads it's a small cut that I caused with a wayward screwdriver while removing a pad washer. Other times there a sort of bump in the pad where it looks like a small hair was somehow glued into the fiber of the skin. This causes the pad not to lay flat against the tone hole edge. I don't think it's actually a hair, but I don't know what it is.

It also seems that as the skin ages it could lose some of its airtight properties through other means. What these are I can't say, as I must admit that I don't know very much about the materials used in pad skins, but it's conceivable that these materials lose their desirable airtight properties as they age and dry out. I know pad skin is usually made from the organ linings of cows, so presumably the skin ages and decays like any other organic matter. All I can say with certainty right now is that it's frustrating to replace pads on an instrument, then find a leak that's coming from an older pad that showed no outward signs of fatigue.

I also learned that you measure chuck keys by the capacity of the chuck and the size of the pilot holes on the outside of it. So a chuck with a 1/4" capacity and 5/32" diameter pilot hole takes a 1/4-5/32 chuck key.

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