The Clarinet BBoard
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Author: Ben Shaffer
Date: 2014-08-14 05:50
Well several months ago my Leblanc Normandy Horn developed a hairline crack on the LH Section from a top key up to the tenon.
My local repairman filled it with I believe crazy Glue and wood powder.
It looked quite nice and sounded as nice as it did prior to the crack.
Well about a week after that the hairline crack reappears.
I called him and he suggested a carbon graphite wrap, or something like that.
He is very busy with school work and it may be months before he can do the repair.
So I keep playing the Horn and the crack seems no worse and even at times almost disappears.
My question is ....maybe I don't even need the wrap, perhaps I can play it for years as is..
Or maybe wait a bit and just get it refilled again in a few months with crazy glue.
So should I just play it as is and forget about it?
The crack is certainly no worse
This Horn he tells me was made after the " Fire" at Leblanc and the wood may have not been seasoned very well.
Its got the logo with a Mountain and circle around it.
The Horn currently sounds quite nice
Are you playing a Horn in this situation?
If so what do you recommend?
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Author: Paul Aviles
Date: 2014-08-14 07:00
The problem with cracks is that they can grow. As you are experiencing, the crack varies with the amount the wood is expanding. The stress of this back and forth is just what might make it worse.
If this is a horn you want to keep (and the cost of the carbon fiber treatment is not prohibitive) I'd highly recommend waiting until the clarinet can be repaired before playing much more on it. Done right, you won't even know there was ANYTHING done to the horn once repaired this way other than the crack will NEVER open up again.
..............Paul Aviles
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Author: BobD
Date: 2014-08-14 16:42
"I'll never say never again" was one of Helen Ward's great songs. I don't know how you can make that statement Paul.
Bob Draznik
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Author: Chris P
Date: 2014-08-14 17:42
I've just had a Couesnon Monopole clarinet come in for a service with a crack in the top joint (top tenon to speaker tube) which I'll be carbon fibre banding soon.
Simply filling a crack in with glue won't always prevent it from reopening - sometimes it may, but usually it'll open up again later when the wood expands again.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: BartHx
Date: 2014-08-14 21:39
I have a Selmer Series 10 that I bought for an extremely good price on that auction site. It had been stored in an attic for several years and had developed two or three hairline cracks (I no longer remember how many it was). I control the humidity in my instrument cases and protect them from excess heat. Within a few weeks the cracks had closed and have never been a problem since. It has not been necessary to do anything else. On the other hand, I am not naive enough to believe that all hairline cracks will respond in the same way.
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Author: Steven Ocone
Date: 2014-08-15 00:07
This time of year you can probably play it without making it worse - unless your air conditioning is turned way down. Just keep an eye on it.
Steve Ocone
Post Edited (2014-08-15 00:08)
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Author: Ben Shaffer
Date: 2014-08-15 04:11
I filled up the hairline crack with super glue. I'll play it a bit and see if it opens again, if it does I fill it again. I'm thinking the crack with at some point stop. I think this is less invasive than a wrap
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Author: Paul Aviles
Date: 2014-08-15 04:55
I say that because the carbon fiber wrap is just that. You carve a groove around the joint at a key point along the crack. Once you've allowed the crack to dry closed, you start wrapping the carbon fiber around the joint, within that groove. There is NO WAY the wood will be able to expand at that point - NEVER. Once you have the fiber wrap in place, you make a super glue/african black wood powder paste and fill the groove (as if you were spackling a hole in a wall). Once that is dry, you sand it flush, stain and finish.
Invisible and permanent.
Of course I don't say you won't ever have another crack in another spot, only THAT spot is pretty much fixed.
As for FILLING the crack with super glue (I'm not a repair person, but....) it sounds to be the opposite of the wrap or pinning (as was once the only FIX for cracks). Filling is an acceptable approach for small surface checks (not all the way through to the bore), I would think filing a deep crack only makes it harder to stay closed and encourages it to go the only way it can which is more open. Someone else PLEASE correct if this is wrong.
..........Paul Aviles
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Author: jdbassplayer
Date: 2014-08-15 04:56
Oiling the the clarinet might keep the wood from changing too much. Just a thought.
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Author: tictactux ★2017
Date: 2014-08-15 11:32
when you fill a hairline crack when it is widest, then it only opens again if the wood is under even more stress than it was when you filled the crack.
If the crack appeared because the wood was too dry or the instrument was dropped, then chances are it'd remain stable as long as you don't go near these conditions again.
Filling a hairline with superglue is a rather quick process. If it holds, fine, else you haven't done anything that would prevent you from doing more invasive repairs.
--
Ben
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Author: John Peacock
Date: 2014-08-15 12:29
Carbon fibre banding seems to be the modern approach, and is probably more mechanically effective, since it clamps the wood uniformly round the circumference. But I don't find it cosmetically attractive, as a lot of wood has to be taken out. We've seen various pictures of such repairs on this BB: while I am impressed at how smoothly the filling can be made to match the surrounding wood, it is overstating things to say that the result is "invisible" - you can always see that something has been done. In comparison, traditional pinning can be really hard to spot if done well, mainly because the area of wood needing filled and matched is an order of magnitude smaller, and also not of such a regular shape.
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Author: Paul Aviles
Date: 2014-08-15 12:41
I agree that the area created by the pin CAN be harder to spot due to size, but the cosmetic end result is up to the ability of the repair person. I had a pinning (four in all across a long crack) where both ends of each pin actually had formed a bump on the surface of the joint (like a little hill). That clarinet looks like the neck of Frankenstein's Monster - not a well executed repair.
So, as with any repair involving cosmetics, the final appearance will be left up to the genius of the one who executes it. I've only seen a few examples of carbon fiber banding repair, but all of those were great.
..............Paul Aviles
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Author: BobD
Date: 2014-08-15 14:18
Wood is one of Nature's materials that expands and contracts with changes in temperature and/or humidity. If you restrict it stress builds up in it. Considering all the holes and machining done on the hunk of wood used for a clarinet section...and the conditions it is exposed to during playing... it's a wonder every wood clarinet doesn't crack sooner or later. Once a crack occurs due to one of those environmental changes it will tend to close up when the environment reverts to what it had been previously. And if you prevent it from closing it may just crack somewhere else.
Bob Draznik
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Author: Steven Ocone
Date: 2014-08-15 16:01
Please note that there is a great variety of super glues. The type that I use for cracks is not at your local Walmart or Home Depot. It is very very thin and will seep down into the crack and into the pores of the wood. Even with this glue I enlarge the crack at the surface to "help the glue find the crack". Later this is finished so that it is not noticeable.
Please note that I usually also pin and occasionally install a carbon fiber band. Most of the time for the repair spent on cosmetics - making all evidence of the crack disappear.
I was taught to let the crack close before pinning the crack by placing the clarinet in high humidity. Then I realized that the crack releases tension. I may let the clarinet rest for a few days, but my intension is not to get the crack to close. Sometimes it will close completely with just a little rest. I have learned to mark the crack so that I can find it. Then I glue and pin it in that position.
Please don't oil before the crack is repaired.
Steve Ocone
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Author: MichaelW
Date: 2014-08-15 18:38
Attachment: Skizze.jpg (46k)
Attachment: SAM_0229.jpg (190k)
My amateurish method: I drill .8 mm holes perpendicularly through the wall, if possible from the inside, at the visible ends of a crack, supposing that will stop the crack from further expanding lengthwise, and some more along the crack, and fill them with thin epoxy resin stained black. In addition I treat a hairline crack with low viscosity cyanoacrylate (superglue). See sketch and foto.
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Author: BobD
Date: 2014-08-15 22:36
Michael: your hole drilling method has been used on various brittle materials, most notably glass. I believe it does have merit.
Bob Draznik
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Author: MichaelW
Date: 2014-08-16 00:44
Exact. I once learned it with acrylic glass. The five or six cracks in clarinets I've treated that way since about three years haven't changed since then. And if you have to make such small holes from the outside, you can easily polish them almost invisible. I must say that these 70 to 100 years old clarinets had only hairline cracks, though mostly through the whole wall thickness. Michael
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