 The Clarinet BBoard
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Author: Kalashnikirby
Date: 2017-11-18 23:23
Attachment: IMG_20171118_195414.jpg (1229k)
Attachment: IMG_20171118_195338.jpg (470k)
2 hours ago, I discovered that almost every post on a older (~1985) Buffet "Professional" bass clarinet I overhaul could be turned by hand...
Researching for ways to fix this, I came across this video:
https://www.youtube.com/watch?v=5F_EvFmnFL8
J.L. Smith proposes putting a little amount of baking soda into the threaded post hole and then to simply screw it tight again. However, at 3:20 you can see how the baking soda doesn't actually remain on the threads, but is most likely blown into the very bottom of the post hole, so I my guess is the effect here is that the post, when tightened, compresses the powder, so it's pushed upwards against the thread, which of course makes it tighter again.
Which is why I imagine that teflon tape for plumping, which is supposed to go on threads anyways, might be the better solution. In fact, I'm pretty excited about the friction and feel when I reinstalled 3 posts using the tape, almost felt like new. As you can see in the first photo, when screwing the post back in, the teflon tape doesn't slip upwards, but stays on the threads.
CA is probably not the best solution, I'd almost ruined one hole using it, plus it might not be easy to do this a second time, should it become necessary. Epoxy seems like an overkill in this situation...
What are your thoughts? I'm sure some pro repairmen on this board have even better tricks up their sleeves, though I'll need them to be quick, since there's at least 20 more posts to go...
Thanks in advance,
Christian
PS: Could oiling have prevented the wood shrinkage?
PPS: Was the Buffet "Professional" a good instrument? Is it worth selling? My once-Teacher doesn't need it anymore, perhaps I could use a bass clarinet
Post Edited (2017-11-18 23:36)
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Author: jdbassplayer
Date: 2017-11-19 00:13
Teflon has one of the lowest coefficients of friction of any material. While it works great for plumbing I would be hesitant to use it to lock threads.
What I do in this situation is wrap the threads a few times with a thin piece of thread or string and reinstall the posts. After this I simply cut the excess off with a sharp razor blade.
PS: It would certainly help, but even well oiled wood changes slightly. If it hasn't been oiled in a while do it now before it gets really cold and dry (assuming you live in the northern hemisphere).
PPS: Yeah they are pretty good instruments. Personally I like Selmer basses better but that's me.
-Jdbassplayer
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Author: Matt74
Date: 2017-11-19 00:54
The standard is dental floss.
Superglue or epoxy is always a bad idea. If it needs either, it needs a pro.
- Matthew Simington
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Author: Kalashnikirby
Date: 2017-11-19 02:36
Thanks for the input.
I tried dental floss, but found the teflon tape to work better! Despite the friction coefficient being lower, it seems that the material compresses more, compensating for the former.
There's also a kind of "reversible" Thread locker (Vibra-tite VC3), that doesn't create a solid bond, but remains flexible. Perhaps worth looking into. Other than that, I'm fine with the teflon tape.
Jdbassplayer, I do live in the northern Hemisphere and IRC, the instrument has been stored in a relatively cold room over years.
Post Edited (2017-11-19 02:37)
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Author: Matt74
Date: 2017-11-19 03:05
Be careful about putting too much material in. It will cause strain on the wood, especially as the instrument regains humidity.
I wouldn't use any adhesive. Even if it's reversible in the short term
If it's been cold a long time it is dried out. Having it oiled properly might be a good idea. It will humidify just being in a warm room, or by being played. As it humidifies the post may snug back up. Wood moves.
- Matthew Simington
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Author: Chris P
Date: 2017-11-19 04:06
I've never had any problem using superglue to secure loose pillars. Others use shellac, or powdered pumice in the pillar hole and others cut shims from paper or abrasive to fit the diameter of the pillar base.
Another way to secure pillars is to drill into the joint and cut into the pillar base, then fit a wood screw in there to prevent the pillar rotating. You can easily remove the pillar by removing the wood screw, then unscrewing the pillar. This is best for pillars that are sprung where the bias of the spring is pushing the pillar anticlockwise (springs should ideally be biased to push the pillar clockwise).
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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Author: Wes
Date: 2017-11-19 04:12
Since I have nylon FF thread handy, I just stick it into the hole, replace the pillar and cut the nylon thread off at the pillar base.
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Author: Kalashnikirby
Date: 2017-11-19 04:52
Chris, this is a good idea for the worse cases!
In the meantime, I've secured a few more pillars. I had to use CA on one where both the thread of the hole and the pillar where severly damaged, it worked just fine, as I was quick enough. Maybe a more gel-like consistency is in order here.
Both superfloss and regular unwaxed floss somehow weren't convinient to handle compared to teflon tape.
Post Edited (2017-11-19 04:54)
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Author: clarnibass
Date: 2017-11-19 10:07
Many methods can improve loose posts but I prefer epoxy and disagree with whoever said it is always a bad idea.
The thing with loose posts is that almost always they can be easily rotated to both directions from their correct position (usually just slightly to close more). Making the threads a tighter fit without glue means the post is still not stopped by the end of the rotation, but just friction in the threads. Teflon tape is often used to reduce friction for the tighter fit it creates, but also mainly to help seal. IME in these types of situations it compresses significantly over time (or maybe a better description is that it is pushed to the "sides") so less likely to remain secure. There are constant forces the spring pushing or pulling the posts slightly.
Epoxy is easily reversible if necessary, though I'm not sure if I ever even needed to remove a post I glued.
I prefer epoxy over super glue because, first, it is much better at filling gaps and, second, super glue sometimes dries really fast when it becomes so thin, making exact adjustment of the post orientations while it dries tricky sometimes.
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Author: Johan H Nilsson
Date: 2017-11-20 23:14
I've used epoxy the few times I've needed to correct the angle of a post. What's the trouble (can harden in 5 minutes depending on kind) and what's the downside?
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Author: Matt74
Date: 2017-11-21 03:54
Epoxy and superglue have their uses, but are not easily reversable. Traditional materials are not always the best, but they can usually be easily undone.
Imagine you are the guy fixing that horn in 2 or 10 years. You want to remove the post for some reason. It won’t budge and you are afraid of damaging the post or body. It may be stuck in with boogers, but you don’t know. You can try heating it to a point, or tapping on it, but you just don’t know what’s in there.
Epoxy can be anything from poorly hardened JB Weld, to NASA quality marine epoxy that lasts 10,000 years under saltwater. It might let go with a little twist, or never come out.
E.G. Right now I have a post with a stuck pivot screw. All the screws had locktite on them (apparently), and not a little dab. They were stiff. With care I managed not to impale myself or strip the heads. Except for one. I tried everything. Oil, alchohol, acetone, heat, freezing, tapping with a hammer. It could be locktite, some other kind of adhesive, cross threaded, dirt, or it might just be “old”, but I assume there’s something on it. One could try a whole variety of solvents, but it’s stuck. It’s in there so bad that when I turn the screwdriver, without slipping, the metal simply deforms without unscrewing. I don’t have the tools to make another screw, etc. Fortunately I got the key off. The screw is in there for good.
When I was a picture frame restorer the absolute worst thing was when someone had put epoxy on the frame. Nothing dissolved it, and it was hard to cut. There were probably different kinds, but it was all extremely difficult to cut or remove. I mentioned the caulking in my other post. There is this kind of outdoor caulking that dries hard as rock. You have to use a hammer and a 5 in 1. If it’s stuck on there good, the wood will actually come off off with it. That’s the way modern materials are. If you know what it is and have the correct solvent you are ok, but you usually don’t know what it is.
Modern materials often seem more convenient than they are. Epoxy is always messy. Thread, tape, or baking soda seem a lot easier to me.
- Matthew Simington
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Author: Tony F
Date: 2017-11-21 10:56
I generally use a dab of the same shellac adhesive I use for seating pads. Works well and easily reversed.
Tony F.
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Author: Kalashnikirby
Date: 2017-11-21 15:36
"Modern materials seem more convenient than they are"
That's a broad generalisation, there are many great materials regularly used by pros and they can't be substituted by anything more "natural". What about CA? When filling tone holes, why not use Epoxy? It will, course, require some researching and testing to determine which adhesive is the most suitable for glueing posts, but I'm sure there is one that fits the requirements. Why should a reversible thread locker not work?
I'm not going to try epoxy on this clarinet, because I'm afraid it'll make a too strong bond, but it's probably ideal for posts with destroyed threads.
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Author: Chris P
Date: 2017-11-21 16:29
Superglue (CA) is ideal for tonehole work as it's instantly workable whereas epoxy takes ages before it becomes workable.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
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