 The Clarinet BBoard
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Author: wayne
Date: 2001-05-22 04:46
How likely is it for a horn to sound differently after a crack has been properly pinned ? Does it matter much where (or, on which section) the repair was made ?
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Author: T. coleman
Date: 2001-05-22 06:25
Unfortunately, in my experience, unless it's halfway down the lower joint or lower, your clarinet will sound 'duller' than before. There are exceptions. But common sense will tell you, any change in the density of the wood will alter its sound.
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Author: Dee
Date: 2001-05-22 10:59
When correctly done, it should make no difference at all in the sound. It doesn't matter where the crack is.
The density of the wood does not affect the sound. You are succumbing to the material myth. If two clarinets were exactly identical except for the material, the sound would be exactly identical. However it is not possible to make two instruments exactly identical whether you use the same or different materials. No two R-13s or whatever horn you favor, sound or play the same. This is why you have to try more than one instrument to find the one you like.
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Author: Anji
Date: 2001-05-22 13:34
It's a common prejudice against crack repair, and bogus.
If the crack repair was not successful, it would be abandoned as a method.
With the lode of vintage horns floating around, you can certainly find good and bad examples of uncracked horns.
The only thing that suffered when my Master Model was pinned was my pride.
Obviously, if you have two horns that play equally well for the same price, chose the one that is uncracked.
It's something that happens to wooden instruments.
You wouldn't ditch a car because of repairs, would you?
anji
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Author: Bill
Date: 2001-05-22 13:50
I am very interested in crack repair. I've been reading everything I can find on the subject. The best article I've seen is in Issue 3 of the Woodwind Quarterly. It's a reprint of an article by Allied. Allied gave up flush banding, because it could constrict/distort the bore. Allied stated that they have done thousands of crack repairs using the pinning method, and the finished work was undectectable.
I wonder how many of us have purchased used instruments that have been (crack) repaired, and we don't know it?
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Author: ron b
Date: 2001-05-22 16:29
Wayne, Dee is right on the money.
The main concern to repair people is whether the crack goes through a tone hole. Those are a little harder to fix. But, a neat job will look great and have zero effect on the intonation - as it originally was for that instrument.
I bought a couple of badly cracked horns because they're good instruments. I can tell you where the crack(s) were since I fixed them myself (worst one was upper joint through three tone holes, by the way). You, however, would have to look intently with a very strong glass to find the repair on your own. Then, I'd still maybe have to give you a clue  I don't know what they sounded like before they cracked because when I got them they were unplayable. Now, they sound just like clarinets :]
I wouldn't hesitate to buy a crack-repaired clarinet because it's highly unlikely to crack again.
- ron b -
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Author: mw
Date: 2001-05-23 02:18
There are exceptions to every rule, so one has to operate carefully. Repaired properly a crack shouldn't rear its head again. However, I think that the type of crack (the manner in which the crack presents itself) has something to do with overall sucess. Unfortunately, lightning can strike the horn twice ... so a crack fixed in one area doesn't mean that the clarinet is less susceptible elsewhere. (not really sure what was being said, no doubt it was the former)
John Butler just got through looking at a nasty lower joint crack that went through the bore ... between top of lower joint & 1st tone hole. Lower joint had other questionable areas, too. ( ... such a beautiful piece of wood, too) This was a problem because the horn was not fixed (originally) properly. Lots of epoxy everywhere. No way to take it apart without (possibly) damaging the wood.
Had what appears to be a developing (?) crack in upper joint.
(( on a R-13 Jubilee (circa anyway) 158,xxx ))
Would someone want to play this horn 3-4 hours a day & risk some problems? I just don't know. I elected to pass on it; I think John was in agreement that the horn had many problems.
Ask John to elaborate on the method use to epoxy (not pin) the "original" problem area. Special method used. Not at all what I would have thought.
Best,
mw
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Author: ron b
Date: 2001-05-23 07:06
mw -
Definitely. Positively. Absolutely :|
There certainly are exceptions to every rule (almost). Some horns are just not worth the effort to repair. Extensive exposure to the elements, flood, etc. could render a piece of wood and metal beyond hope of restoration. I mean, it just wouldn't be cost effective to do it. It could add up, in time and material, to more than the price of a new one.
True story: Guy brings into shop a bashed in ukelele, wants it restored to original condition. Boss explains that the cost would exceed the price of a new one - of which there were a quite a few in stock. Ukes were very popular at the time and, in the early sixties, not terribly expensive. In fact they were pretty reasonable... uh, cheap. No, customer insists. I belongs to a friend and he must return it and doesn't want friend to know it got crunched at a wild party - friend will know if he returns a different uke : I fixed the uke - pried, clamped, glued, tweezed and sanded and finally re-lacquered the thing. Customer scuffed it a little here and there and was pleased as could be Happily paid the bill - about three times the price of a new one.
The repair persons' job, besides doing it well, is to save the customer money but, sometimes... whatta ya gonna do?
- ron b -
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Author: Gordon (NZ)
Date: 2001-05-23 12:10
If a clarinet is less reponsive after a pinning job I suspect that is because there are still leaks. It can be quite tricky to eliminate leaks associated with a crack, especially if it goes through tone holes, vent tubes, or posts, which it often does. I find the filling/sealing, and finishing is a bigger job than the pinning itself.
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Author: Bill
Date: 2001-05-23 12:18
Author: Gordon:
I find the filling/sealing, and finishing is a bigger job than the pinning itself.
-----------------------------------------
Gordon: Right on! This is what the Allied ariticle, I mentioned above, said about pinning.
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Author: Terry Horlick
Date: 2001-05-24 00:25
Pinning cracks seems to be the current approach. If you see an old horn with a flush band repair should you steer clear? <Ul><LI>Will it have a damped stuffy sound?<LI>Will it be likely to crack more?<LI>How much (ie. what percent) should the value be discounted from a non-cracked horn?</UL>
Thanks, Terry
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Author: mw
Date: 2001-05-24 02:15
Banded horns seems to have a very poor resale value. IMO, its one thing to know a horn has been pinned, its another to have to look at it daily & be reminded.
Cracked-but-repaired with-a-band horns that I have played have felt fine; no leaks. If banded properly I think it's a permanent fix.
The loss of value is a very subjective thing, as is the "look".
Best,
mw
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Author: jbutler
Date: 2001-05-24 03:25
Responding the the epoxy method mw brought up..it is called the Pilczuk method. I first heard of it in 1984 when NAPBIRT published a compendium of repair techniques. Basically it involves plugging tone holes and the bore of the instrument up to the area that has developed the crack. The joint is steamed to force the crack open. Using compressed air MEK (Methyl-ethyl-ketone) is forced through the crack using 25lbs of compressed air. This is done until the MEK comes out light colored. This process is used to remove any pith and oils in the crack. Next epoxy is applied to the inside of the bore along the crack line. Using 75lbs of compressed air the epoxy is forced from the bore to the outside of the clarinet. Excess epoxy is swabbed out of the bore and the clarinet is allowed to rest overnight while the epoxy cures. I've used this method twice. Once on an alto clarinet that had a rather long crack running through two tone holes, and once on a Bb that crack in an area where pinning was impossible. I feel like the compressed air puts stress on the wood, but sometimes you gotta' do what ya' gotta' do. If anyone is interested in the complete details of this process you may email me with your fax number and I'll fax it to you, or send a SASE to:
John Butler
Instrument Restoration
935 Eldridge Rd #337
Sugar Land, TX 77478
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Author: jbutler
Date: 2001-05-25 00:03
1) Haven't heard of graphite bands, but assume it is the same as flush banding with silver or nickel silver bands. It is probably less conspicuous. 2) I don't understand the comment about immobilizing one side of the tube. The pin is acutually a threaded rod and it brings the wood together by moving both sides toward each other...so I don't get the above comment. 3) I've never pinned an instrument and had it lead to "further cracking"....maybe it has happened to others, but not to me. Gordon...please give your reaction. You have a wonderful analytical mind and may bring up a point or two that I've overlooked.
I would be interested in seeing the graphite banding process.
John
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Author: Anji
Date: 2001-05-25 01:43
Would it be possible to perform the epoxy repair using a partial vacuum?
(Instead of pressurizing the bore?)
My inquiry is not purely academic, there's something I want to work on.
(Didn't the old-timers fill cracks with hot wax?)
Under a partial vacuum, I think MEK or similar solvents would boil off, before they passed by capillary action.
A vacuum would be an ideal mode for extruding epoxy, little extravization and the crack should be completely filled.
Any flush banding technique requires turning the section on a lathe and special dies to set the bands (doesn't Ferre's sell a kit?), this epoxy technique from JB should require very few tools.
anji
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Author: Gordon (NZ)
Date: 2001-05-25 04:45
jbutler I don't think pinning draws the timber together because unlike when using a scrrew or bolt, the timber on BOTH sides of the split get to be threaded. It just holds the split in the position it was in when the rod was screwed in.
What a can of worms this topic is. I was hiding but jbutler has naughtily asked my opinion. Books could be written on splits, both on what does happen and what theoretically could happen.
I believe there are three quite separate issues involved in dealing with splits.
One is the stabilization. This has two aspects... keeping the split from travelling further, and stabilizing the width of the split opening (especially when the split crosses tone holes). I think that in many cases the split relieves stresses inherent in the timber, and as long as the instrument is not subject to huge climate (humidity) changes movement is no longer a problem. Stabilization in these cases is not really an issue.
I have seen glued splits open with timber movement, resulting in difficult-to-trace, almost invisible leaks. I have very little confidence in adhesives (epoxy or cyanoacrylate) holding a split in the face of timber expansion, especially on this rather unabsorbent material which is likely to have traces of oil or moisture in the timber/glue interface. I imagine it only needs a layer of oil or water a few molecules thick between the timber and the adhesive to make the adhesive very weak indeed. Note that if the split is stable the adhesive is being used as a filler rather than an adhsesive.
The second issue is filling any leaks that the split may have caused. If the split is stable this is not a problem. Shellac, epoxy, cyanoacrylate can all be used. Shellac and CA are very inflexible so I avoid them, although CA with grenadilla 'chips', and the new cyanoacrylate-with-rubber-dust are probably more resilient. If there is any instability of a split then a flexible filler (e.g. silicon rubber)would be ideal, but cannot be finished well cosmetically, and in a tone hole split it will 'dip' as the split opens, compromising the seal of the pad.
If pinning or other stabilization is not involved then the following is worth considering, especially for tone hole splits: If the width of the split varies say from 0.1 to 0.15 mm then no fairly rigid filler like epoxy can accommodate the 50% change, but if that split is cut to a width of say 0.5 mm before filling then the variation would be form 0.5 to 0.55 (i.e. 10%) and the epoxy may accommodate this. (Figures are illustrative only) I have found this often successful. For relatively minor splits that are not likely to continue I sometimes cut the split wider, say 3 mm deep, (with a 6 or 8 mm diameter circular saw type of blade in a dental micromotor) and fill with black epoxy or CA+grenadilla.
The third issue is cosmetic. That speaks for itself, but a filler is easier to camouflage if it is a fairly rigid material like the timber.
Thoughts On The Pilczuk Method:
- As mentioned before, I am reluctant to trust epoxy as a split stabilizer.
- Clearly this is suitable only for major splits that go right through the body.
- Somebody (either this forum or the repairers' one reported using steam or water to open a split and the result was that the entire section split in two! Besides, if a technique is going to swell the bore-side timber enough to open the split more, then after the job is done and the timber shrinks again we are inviting shrinkage splits INSIDE the bore. You can't win!
- It sounds very messy indeed.
- I suspect that the solvent will 'carry' oil from the bore surface of the timber INTO the crack rather than effectively CLEAN the crack. We only need minute traces of oil to compromise the adhesive.
- Does the solvent dry out the steam-dampened surfaces of the split?
- I don't know how the pressure forces epoxy THROUGHOUT the split. I would expect it to blow out through the easiest route and then keep to this route, without penetrating any slightly more difficult areas of the split.
I believe that nothing forces epoxy into a crack better than repeated pressing and wiping with a epoxied finger! I have also found a needle-less hypodermic spring good for this purpose.
Regarding the website referred to:
1. What an enormous price!
2. I am assuming that a groove is cut (lathe job) around the body as for flush-banding, carbon fibre thread wound around in the groove in conjunction with the groove being filled with epoxy. Perhaps I am wrong though.
3. I have never come across an instrument that has "cracked on the other side" following pinning. That may be scare-mongering. However the claim that pinning could cause bore distortion/warpage may be valid, especially with low-quality, more easily distortable timber. But I think that if there is any stress-raising effect from pinning leading to further splits it would be in the vicinity of the ENDS of the pins. I have never encountered this either.
Who knows.. bore distortion may make the instrument sound better! The latest model of Selmer (Paris) soprano sax has deliberate corrugations in the bore of the neck.
4. Many cracks will not close. To close them would mean putting bore-side timber under enormous compression and very likely reducing the bore diameter in the process.
5. If it is as I described then carbon fibre would constrict the expansion ("flex with humidity") every bit as much as a brass or silver band.
6. If the split is indeed stabilized then the replacement tone hole will produce a nice new edge for pad sealing. If the split is not toally stabilized than this cap could have problems with air leaking around it. I have had no problems filling stabilized splits in tone holes with black epoxy. For any chips I drill and fill the same way a dentist does a tooth cavity. (Note that when "joint expansion" is mentioned he no doubt means expansion of the timber of the entire clarinet section (joint) rather than a split expansion.)
7. The stresses established while screwing in a pin mean that it is risky close to a tone hole. A bound fibre method would be safer here.
If a fibre binding is not the method, referred to then perhaps it is a method that could be considered.
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