Detecting leaks
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Detecting leaks
I have a flute here which i suspect to have a little leakage at the joint or an repaired crack nearby. She plays very well in tune but seems to be a little rough and week in sound. How can i detect the leakage without doing any harm to the flute?
First play the flute and observe the sound.
Then run water through the bore. This will seal any small cracks temporarily. If the flute sounds much more stable you know there is a crack. It won't necessarily tell you exactly where the crack is but at least you'll know if it's cracked or if that is just the normal sound of the flute.
Then run water through the bore. This will seal any small cracks temporarily. If the flute sounds much more stable you know there is a crack. It won't necessarily tell you exactly where the crack is but at least you'll know if it's cracked or if that is just the normal sound of the flute.
Hi Lowblow,
Good advice from Brian!
That would be the way to quickly check for leaks. I submerge the flute in a bath of room temperature water for 10 seconds. I would test as is with the water droplets inside and then again after a quick swab to note any differences. If there is a dramatic change in Otsu no RO, you've got a leak.
Let us know what you find!
Namaste, Perry
Good advice from Brian!
That would be the way to quickly check for leaks. I submerge the flute in a bath of room temperature water for 10 seconds. I would test as is with the water droplets inside and then again after a quick swab to note any differences. If there is a dramatic change in Otsu no RO, you've got a leak.
Let us know what you find!
Namaste, Perry
Here's another way used to test concert flutes, but which will work even better for a shakuhachi. Close the end by pressing on your bare thigh or calf. Cover all finger holes, put your mouth over the utaguchi end and suck to create a partial vacuum. If it holds enough of a vacuum to "pop" when you pull it off your leg after five seconds, it basically is not leaking enough to matter. It should hold a seal for over ten seconds if there are no cracks and the joint seals well.
"Toby""Toby"Here's another way used to test concert flutes, but which will work even better for a shakuhachi. Close the end by pressing on your bare thigh or calf. Cover all finger holes, put your mouth over the utaguchi end and suck to create a partial vacuum. If it holds enough of a vacuum to "pop" when you pull it off your leg after five seconds, it basically is not leaking enough to matter. It should hold a seal for over ten seconds if there are no cracks and the joint seals well.
Very good. I will do this with using my wifes belly to close the end.
"Toby""Toby"Here's another way used to test concert flutes, but which will work even better for a shakuhachi. Close the end by pressing on your bare thigh or calf. Cover all finger holes, put your mouth over the utaguchi end and suck to create a partial vacuum. If it holds enough of a vacuum to "pop" when you pull it off your leg after five seconds, it basically is not leaking enough to matter. It should hold a seal for over ten seconds if there are no cracks and the joint seals well.
Used this method. The flute is sealed.
I find a third method. Use an human leaking detector (aka teacher). Will use when i met him. I know his answer already "It is not the flute"
"LowBlow""LowBlow"
I find a third method. Use an human leaking detector (aka teacher). Will use when i met him. I know his answer already "It is not the flute"
I wouldn't be so quick to assume that it's not the flute. Previously cracked shakuhachi and shakuhachi with joints are prone to leakage. Additionally, the leaks can be elusive because as you (and the flute) warm up and condensation coats the bore the leaks can become less noticeable.
Are you storing the shakuhachi properly in a plastic bag? I've found that it can make a huge difference with previously cracked flutes.
My thoughts are that pouring water down the bore is a more reliable method of checking for leaks because with Toby's method there is a bit of a learning curve to determine how much of partial vacuum to create. What were the results of the water in the bore test?
"CharlesKoeppen""CharlesKoeppen""LowBlow""LowBlow"
I find a third method. Use an human leaking detector (aka teacher). Will use when i met him. I know his answer already "It is not the flute"
I wouldn't be so quick to assume that it's not the flute. Previously cracked shakuhachi and shakuhachi with joints are prone to leakage. Additionally, the leaks can be elusive because as you (and the flute) warm up and condensation coats the bore the leaks can become less noticeable.
Are you storing the shakuhachi properly in a plastic bag? I've found that it can make a huge difference with previously cracked flutes.
My thoughts are that pouring water down the bore is a more reliable method of checking for leaks because with Toby's method there is a bit of a learning curve to determine how much of partial vacuum to create. What were the results of the water in the bore test?
Yes it is stored properly. It is not yet my flute. I have this flute for audition. I don't want to do the water test.
I'd be hesitant about the water test in that case too. However, I wouldn't mind hearing what the thoughts of others are about that because it's an interesting situation. Is it OK to do a water test on an audition flute?
"CharlesKoeppen""CharlesKoeppen"Is it OK to do a water test on an audition flute?
Yes, bamboo is not a fragile thing.
I wouldn't hesitate doing the water test on an audition flute. Bamboo is nor fragile as Tairaku says and it would not crack or get damaged due to a water test... and after the test you wipe it off with your tsuyutoshi and that is it.
"Kiku Day""Kiku Day"I wouldn't hesitate doing the water test on an audition flute. Bamboo is nor fragile as Tairaku says and it would not crack or get damaged due to a water test... and after the test you wipe it off with your tsuyutoshi and that is it.
What about the rattan bindings? They are lacquered but the the lacquer is partly gone. Don't they soak and swell?
Should not be a problem if you don't leave the thing floating in the bathtub overnight. That being said, if it passes the vacuum "pop" test I really doubt it is a leak. A flute leaking enough to seriously affect the sound will not even pop, as it leaks in air as fast as you suck. Is the sound rough and weak over the compass of the instrument or only on certain notes, and if the latter which ones? Is it jinashi?
"LowBlow""LowBlow""Kiku Day""Kiku Day"I wouldn't hesitate doing the water test on an audition flute. Bamboo is nor fragile as Tairaku says and it would not crack or get damaged due to a water test... and after the test you wipe it off with your tsuyutoshi and that is it.
What about the rattan bindings? They are lacquered but the the lacquer is partly gone. Don't they soak and swell?
I've never had any problems with the water test, even when there were cracks in the urushi inside. It's done for 10 seconds or less. However, any exposed ji plaster, whether under urushi cracks or inlaid rattan, can be at risk if the moisture is not removed. As Kiku said, if you swab the bore after and dry the outside with the Tsuyutoshi, it should be fine.
(BTW some people like to leave the beads of breath moisture inside the bore as the extra humidity may prevent cracking. This may work, but it also eventually leads to a funky smelling flute.
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