 The Clarinet BBoard
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Author: jim lande@ erols.com
Date: 1999-10-10 05:34
I just finished repadding a metal Selmar Bb from
around 1930. Two of the pivot screws bind, slightly.
Obviously, I can leave some slack in the screw (and then hope that I can find them when they shake out in the case.)
The pivot screws are the point type, rather than the rod type.
Should I get a reamer or should I sand the points (not to flaten, but to take some metal from the whole 'cone')?
Just curious, any preferences point types vs rod types?
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Author: ron
Date: 1999-10-10 07:06
Jim -
Could be several reasons for a pivot screw to bind and many ways to correct the problem. The hinge could be bent ever so slightly, ends worn (that would be my first suspicion with a horn that old) or worn screws (maybe). Is it a ring key hinge and, if so, does it bind at the chimney? Have you tried new screws?
If you have a repair manual you'll find there are several approaches to this including, with a metal horn, bending the posts a tiny bit, probably NOT the best solution. The WORST remedy is to loosen the screws. If you can drill into the end and silver solder a piece of solid nickle silver tube into the hinge end, then a reamer (broach type) and tube shortener would probably best solve your problem -- a lot of work. It's up to you whether you feel the instrument is worth spending that much time on (well, after all, it's a Selmer).
I certainly don't pretend to have all the answers but I'd try the simplest things first - did you oil it?
Ron
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Author: Kimberly Nisius
Date: 1999-10-10 13:33
As for a fix to a screw backing itself out when you don't have it tight in the post, try some lock-tight on the threads of the screw. The seal of this is breakable if you need to later adjust the screw or fix pads again. Or the other fix-it is to place the screw where you want it and then dab just a little clear nail pollish over the end of the screw and post. This, too, will hold it solid, and can be easily broken if you need to do some fix, either by just turning the screw, or using just a little nail pollish remover before turning the screw.
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Author: jim lande@ erols.com
Date: 1999-10-10 22:43
While the Selmar is about 70 years old, I don't think that
it has all that much wear on it. The pads were the leather type that were punched out of relatively thick leather and then glued onto cardboard backing. You can see the grain of the leather from the side. There is no felt in the pads. They are floated on more than 1/16" of shallac. I don't think these pads have been available since the 1940s. It would not surprise me if these were the original pads. I have heard that they wore very well.
There is no wear on any of the touch points and the case, though not original, looks mint. In fact, the pads looked almost new and my first thought was that the horn was going to play as is. Ah, but while the horn does not have an articulated C#/G#, it does have that chimney over (and the corresponding hole through)the tenon. This placement makes it easy to mash the pad with the bridge mechanism when you put the horn together or take it apart. The one leather pad had been mashed. I thought I could replace the one pad and the horn would play. Nope, the horn was out of adjustment. I needed to fool with the bridge mech. Still no luck, the old pads lacked enough resiliance to make a good seal. Still, there is no real indication that the horn ever was used.
I took the horn apart, polished everything, replaced several springs and a few of the bumper corks, and all of the pads. I thoroughly cleaned all of the rods, using new oil to cut the old oil, working the hinge screws through, and then cleaning. I didn't notice the keywork being much gummed up.
There is no bend in the keywork -- the keys fit very nicely between the posts. I don't see how pivot screws could wear in a way that would let them push in too deap.
My concern with either locktight (which I understand can work too good) or clear nail polish is that there will be a little gap inside the screw post that should be filled with the pivot and won't be and that extra gap will promote corrosion. But this concern may be unfounded.
Any more advice?
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Author: Doug P.
Date: 1999-10-11 13:23
The old fashioned solution to this often common problem, used long before locktite, was to insert the pivot screw, but not all the way to the binding point. Wind a bit of ordinary thread (cotton is better than other types)once or twice around the screw just below the head. Snip it off cleanly so there isn't something hanging off the clarinet when finished and then screw the pivot screw into the post. You may have to do this a few times to find the exact amount of winding you will need. This technique keeps the screw from reaching the binding point, yet fills the gap at the screw head. If the screw is removed, of course the thread is lost and this needs to be done all over again. Doug P.
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