Author: Ken Shaw
Date: 2001-11-27 21:56
There was a very good thread on blow out a couple of years ago at http://www.sneezy.org/clarinet/BBoard/read.html?f=1&i=15949&t=15910 . I wrote then:
I think the definitive explanation of "blow out" was given by a series of postings on the Klarinet board last year. Ed Maurey wrote at http://www.sneezy.org/Databases/Logs/1999/06/000786.txt where he wrote: "You can run a flap hone with 400 grit paper at 1,000 RPM for 60 seconds in the bore of a clarinet joint and not be able to measure a diameter increase. [You will, however, make it nice and shiny.] How a cloth swab could ever enlarge a clarinet bore is beyond me."
Alan Swiney agreed, writing at http://www.sneezy.org/Databases/Logs/1999/06/000791.txt :
"You are right. Cloth swabs don't change the bore through wear but they do change tone holes drastically. When the bore contracts so does the wall of the clarinet. When the wall of the instrument contacts the tone holes get smaller. When the tone holes get smaller the pitch gets flatter and stuffier.
"Lets talk about the swab! The swab is used to clean the BORE! Right? The swab never makes contact with the tone hole wall or undercutting. Usually when a clarinetist has finished playing, they must blow the water from the tone holes or used a pipe cleaner. The pipe cleaner only gets the cylinder clean but the undercutting is left untouched. As the swab is pulled though the bore, lint or fibers from the tight swab will build up in the bottom section of the tone holes, especially with cotton swabs.( I recommend silk swabs as they shed less). This fiber build up acts as a filter. As saliva and condensation runs down the bore of the horn, this fiber filter sucks it right into the tone hole.
"Next the Moisture dries and leaves natural minerals like calcium in the fiber filter. Over a period of time the a crusty plaque will form in the tone made of lint, fibers and calcium. This Build up is very similar in appearance to calcius or dental plaque. Eventually this plaque will decrease the tone hole volume and occlude the undercutting thus making the clarinet play in a "blown out" manner. Each month I remove a tablespoon of plaque from or local symphony clarinetist's instrument.
"Chronic water gurgles are also a sign of fiber build up or tone hole plaque. I originally discovered tone hole plaque while doing medical studies on clarinets. I was X-raying some of the clarinets that I inherited from my Repair teacher W. Hans Moennig. These white rings kept appearing at the apex of the undercutting with a resolution very similar to human bone. It was quite confusing to me because I could not find foreign material via the bore or tone hole cylinder. I used a proctoscope to view the undercutting and there it was Big as Day, a I.5 mm protrusion into the air path. At that point I design a cleaning tool that matched the tone hole profile. The tool was designed to reach the hidden section of the undercutting that the swab never cleans. After carefully removing the old plaque build up from the tone holes the instrument was much more resonant.
"In addition to improving the pitch and timbre, Removing swab and fiber plaque can also reduce wood cracks though tone holes. Such cracks are very common on the top joint side B and Bb trillers, throat A, and the Left hand G# hole. If you have a new clarinet, now is the time to clean the plaque from the tone holes. I will be glad to mail you information on the cleaning tool and how to use it, if you don't already have it. Just send me your street address as I don't have a scanner yet.
"I hope this posting will help clarinetist better understand the age old problem of pitch change due to tone hole plaque and Not Bore Blow Out."
This is the only satisfactory explanation I've seen for "blow out," and it seems to have settled the issue on the Klarinet board, at least for the time being.
However, I can speak from experience that the situation with barrels is different, at least when they are new. The high moisture level, combined with the altered stress patterns when the bore is drilled, mean that that the bore, and particuarly the sockets, of a barrel will nearly always shrink slightly. This results in "frozen" joints that occur so often between the upper joint and the barrel on new instruments. At least with Kalmen Opperman's carefully "tweaked" barrels, you must always bring a new one back for readjustment of the bore after a month or two, or even several adjustments, particularly if it is made of rosewood, which is his preference.
Several years ago, I went to a concert where Harold Wright played the Brahms Quintet with the most beautiful tone I have ever heard. I can still remember where I was sitting and how wonderfully he played. I learned that he was playing Ralph McLane's A clarinet, which at that time was well over 50 years old, yet was still, according to Kalmen Opperman, the finest A clarinet in existence.
Best regards.
Ken Shaw
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