 The Clarinet BBoard
|
Author: perryg114
Date: 2007-10-02 01:21
Attachment: tenon crack.jpg (248k)
This is a pic of a tenon crack on a Martin Freres Lamont Clarinet I bought off Ebay. It is in real good shape other than this crack (actually two). It looks like someone dropped it on the floor and the impact chipped the tenon and caused these internal stress cracks. The joint seems stable at the moment but without intervention I doubt it will be that way for long. I was thinking of epoxie to glue it back together and stabilize the crack. I know some recommend super glue but my experience with super glue is that it breaks down in about a year from moisture. Can this be fixed without a major pain or should I make a lamp out of it?
Perry
Post Edited (2007-10-28 15:02)
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-02 07:23
Attachment: tenoncap.jpg (12k)
Have the tenon capped, ie have a metal cap/sleeve fitted over it.
Superglue might fill the crack, but it won't protect the tenon from new stress.
--
Ben
|
|
Reply To Message
|
|
Author: bwilber
Date: 2007-10-02 11:37
Is there anyone that sells tenon caps? If not, how much does it cost to get a tenon capped, generally? Thanks
Bonnie Wilber
|
|
Reply To Message
|
|
Author: BobD
Date: 2007-10-02 12:35
You don't say how the horn plays or the value you place on it. My initial thought is "Now you know why it was offered for sale.". Personally I doubt there is much point in putting much more money in this horn thefore the superglue or epoxy is worth trying. First you should
try to clean the crack adequately using some solvent and this could be an extended procedure. If it were mine I'd try a thin epoxy and then wind string around the outside circumference and leave for at least 24 hours. I am not a clarinet lamp fan. That is "some" closeup!
Bob Draznik
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2007-10-02 13:54
One thing good about a low viscosity superglue is that it wicks right to the bottom of the cracks. I've found gluing tenon splits remarkably successful. However because of the nature of the damage on this one, a crushing in rather than simple splits, I would recommend following up the gluing with the further stability that a cap offers.
For what it is worth, one method I developed for making a tenon ring/cap is described in http://test.woodwind.org/clarinet/BBoard/read.html?f=1&i=244124&t=244124
See my 2 posts on 2007-04-25
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-02 16:14
I don't have any Sterling Silver Sheet Lying around. I wish I had several 1000 lbs of it to tell you the truth. If I could find some caps that are already stamped out of metal I could probably do the lathe work since I have access to a lathe here at work. It is hard to make a cap out of thin metal like that from scratch although I guess you could leave alot of extra meat on the cap then machine it off after it is glued to the tenon and the whole assembly is chucked up in a lathe. Yes a cap would be best for protecting this. I was also thinking of an internal sleeve but that is probably going to change the accoustics a little even if it is flush with the bore. Since the joint is being loaded in compression an internal sleeve would strengthen that area.
Funny thing is this Martin Freres (wood) is almost an exact copy of a hard rubber Robert Thibaud that I have. The Thibaud is the better sounding of the two in my opinion eventhough it is rubber. Both are French Made Horns.
Perry
|
|
Reply To Message
|
|
Author: DAVE
Date: 2007-10-02 16:27
i know this is off topic, but what kind of camera did you use for that pic? The detail is amazing.
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-02 17:47
The camera is a Canon A620 which is out of production but I think the A640 is the same with 3M pixel better resolution. It is like a little microscope. I use one at work as well and it comes in handy. You have to have it in macro mode with the lens at full wide angle. There is some distortion but it is not that bad. You can almost touch the lens with an object and have it be in focus.
http://www.newegg.com/Product/Product.aspx?Item=N82E16830120068
Perry
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-02 17:54
I don't plan on putting much money into it. I got the seller to come off the price $20 because of the undisclosed damage so I paid like $35 for it before shipping and it had a decent B45 mouthpiece on it so I am not out too much on it. It is a pity it was not taken better care of because the condition is good for something that old. I am guessing it was made in the 50's. I am buying stuff to fix up and either play, sell, or make lamps out of.
You don't say how the horn plays or the value you place on it. My initial thought is "Now you know why it was offered for sale.". Personally I doubt there is much point in putting much more money in this horn thefore the superglue or epoxy is worth trying. First you should
try to clean the crack adequately using some solvent and this could be an extended procedure. If it were mine I'd try a thin epoxy and then wind string around the outside circumference and leave for at least 24 hours. I am not a clarinet lamp fan. That is "some" closeup!
Bob Draznik
|
|
Reply To Message
|
|
Author: BobD
Date: 2007-10-02 20:11
"I am buying stuff to fix up and either play, sell...."
Sounds familiar!
Bob Draznik
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-02 20:31
>> "I am buying stuff to fix up and either play, sell...."
>
> Sounds familiar!
<raises hand>
Newest project is a Mazzeo triplet. One for me, two for ... ![[wink]](http://test.woodwind.org/clarinet/BBoard/smileys/smilie3.gif)
--
Ben
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-02 21:15
Attachment: tenoncap.jpg (30k)
bwilber wrote:
> Is there anyone that sells tenon caps? If not, how much does it cost to get
> a tenon capped, generally? Thanks
Bonnie,
Amati has tenon rings (see attachment - they're not simple caps but rather sleeves) as replacement parts. A good dealer should be able to order them.
(check this .pdf for part numbers)
--
Ben
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-03 12:05
Those look like they would do the trick for my repair as well. That internal lip will really strengthen a tenon crack that originates at the tip. What materials would be considered acceptable to make a tenon ring out of? Stainless would be the best but is a pain to machine. Aluminum or brass would be a much better choice from the standpoint of being machinable. I figure brass would turn green.
Perry
"Bonnie,
Amati has tenon rings (see attachment - they're not simple caps but rather sleeves) as replacement parts. A good dealer should be able to order them.
(check this .pdf for part numbers)
--
Ben"
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-03 12:24
> Aluminum or brass would be a much better choice from the standpoint of
> being machinable. I figure brass would turn green.
I think it's some kind of brass or bronze. And it is lacquered, probably to prevent the patina. The metal reminds me very much of what's used in rifle shell casings.
--
Ben
|
|
Reply To Message
|
|
Author: Chris P
Date: 2007-10-03 13:50
They're normally made from nickel silver and left unlacquered or unplated, though brass or solid silver can also be used, either turned from a solid bar, stamped from sheet metal (and turned to size) or made from sheet metal parts that are cut to size, hard soldered and then turned to the finished size. Nickel silver, as well as brass and solid silver will tarnish but that's normal and can be cleaned up with 1200 grit to a bright finish (usually when replacing the tenon cork).
Tha Amati one is like the older Selmer one which enter the top part of the bore and these are more costly to make and fit. The normal tenon caps will cover the end of the tenon without going into the bore and are much easier to fit (and replace if need be).
With the knd of damage this tenon has had, it's probably best to make a mandrel to fit inside to push the broken section outwards and glue with the mandrel in situ, then remove the mandrel and clean up the inside of the bore so it's all smooth, and then fit a tenon cap to not only strengthen the tenon, but also hide the repair.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: EuGeneSee
Date: 2007-10-03 14:02
<. . . and glue with the mandrel in situ.>
Chris:
Is there something that should be smeared on the mandrel so that your famous superglue doesn't make the mandrel a permanent fixture in the bore when the SG wicks through the crack?
Eu
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-03 14:20
EuGeneSee wrote:
> Is there something that should be smeared on the mandrel so
> that your famous superglue doesn't make the mandrel a permanent
> fixture in the bore when the SG wicks through the crack?
wrap the mandrel with wax paper (at least on the glue side).
--
Ben
|
|
Reply To Message
|
|
Author: BobD
Date: 2007-10-03 14:35
Chris' metholodogy sounds good to me since the crack is actually two cracks and the in between section has been displaced inwards. Personally I would not try to use aluminum as it will pit. Tenon fitting may sound easy but I don't believe it is. Beeswax or paraffin on the mandrel maybe.
Bob Draznik
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-03 15:16
I could machine a mandrel out of polyethylene nothing sticks to that. Yeah I was thinking something would have to go in the bore to push the crack shut before glueing and then capping. Brass is doable for a cap. Probabably the outside diameter and maybe the inside would be left fat and the final machining would occur when the cap is glued to the body and then the assembly would be turned to complete the machining. This will be a fun test just to see if it works. I figure I can't hurt it worse than it is. I can still make a lamp out of it.
Perry
|
|
Reply To Message
|
|
Author: clarnibass
Date: 2007-10-03 15:40
You can put cork grease (I recommend the one from Doctor's Products which I think it is made of beeswax).
Gordon, I read your method and couldn't understand some of it. It sounds like you are making a ring that is longer than needed, and then you press the extra over the end of the tenon? I'm probably not understanding this right. Also do you not remove any material from the tenon, and is this ring supposed to take the extra space already existing?
I also have questions (Chris, Gordon, anyone?). I think if I made a cap it would be easier to turn from rod (probably brass). Is it better to have the cap right to the end of the cork groove, or leave some of the thicker wood and align the cap with it? In Ben's second photo it looks all the way to the groove but in the first picture I'm not sure, might have some wood between the cork and the cap.
Also if I turn from rod, is it better to leave thicker walls and then turn accurately after gluing it (in that case, how would you hold the clarinet on the lathe?) or maybe it is possible to bore a thicker rod, then turn the outside with something like machinist wax to make the thin walls?
Thanks!
|
|
Reply To Message
|
|
Author: Chris P
Date: 2007-10-03 15:58
A plastic mandrel will work well as it will come away easily if it gets superglue on it, then the glue in the bore can be removed with fine abrasive paper (1200 grit) glued round a piece of dowel.
To fit an existing tenon cap to a tenon (either bought from a manufacturer or made yourself), mount the joint in a lathe and turn the end down in both diameter and length to fit the internal dimensions of the tenon cap (so it's a tight fit).
Glue the tenon cap on and then turn it down to the right size (but only just slightly narrower than the socket into which it fits) and the right length so the end of the tenon is touching the base of the socket, but not leaving a gap between the shoulder and socket ring when the joints are together, and neither leaving a gap between the end of the tenon and the base of the socket.
Round off the end so it doesn't chew up the socket and paper it all up smooth with 500, 800 and 1200 grit, then a final polish with buffing compound so it shines (with the joint mounted between lathe centres and spun at high speed to get a good finish). Fit the tenon cork and you're done.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-03 16:00
Clarnibass,
the first picture is from my Marigaux, it has a "simple" cap that goes not inside the bore.
The second one is from the Amati, and the cap goes right to the cork groove, in fact it has a shoulder/bevel there (so the outer flank of the cork groove is metal from the cap). The tenon end has to be turned down according to the ring's wall thickness - inside and outside.
--
Ben
|
|
Reply To Message
|
|
Author: clarnibass
Date: 2007-10-03 19:20
Perry, I assume that picture was to help me. Thank you, but I can visualize how each part need to be and what to turn, etc. Since I'm a beginner with machining what I can't really understand is how to actually do some of it - the technical details. For example holding and turning such a thin piece of brass seems impossible. Also I can only think of a way to hold the joint with sort of a mandrel that will squeeze on it from the sides, so prevent working on the end of the tenon. How should I hold the clarinet to work on the end of the tenon or the bore? How to shape the cap on the lathe? etc.
By the way, on the Buffet Prestige (and probably other Buffet models with metal caps) the caps are not even on the entire end of the tenon. If you look at the tenon end it looks like a wood ring with a metal ring around it. Just another possibility.
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-03 19:58
I have not tried chucking up a wooden clarinet in a lathe as of yet. I have never tried to machine wood, especially damaged wood. As for the cap, I would machine it plenty fat so it won't collapse from being too thin when chucked up in the lathe. So you would start with a cap that has the correct internal dimensions to fit over your modified tenon. You will have a metal disk that is maybe 1/4" thick and 1.5" in diameter with what amounts to an O-ring groove in it that matches your modified tenon. Now you epoxie that ring on with the best epoxie you can find. JB weld is pretty good stuff although there might be something better out there. Now you have a way to hold the disk to cut the ID and OD and thickness down to the proper dimensions. This is the approach I would take but I can't say if it would work or not.
This article that someone already posted should help.
http://www.voicemovement.com/lathe_in_the_woodwind_shopbianchi.pdf
Perry
|
|
Reply To Message
|
|
Author: tictactux ★2017
Date: 2007-10-03 20:56
Attachment: capmilling.png (2k)
Perry,
yes, you mount an oversised cap and then turn it down to dimensions. Upon closer inspection on the Amati front, one can still see (or rather feel under the finger nail) the ever so tiny grooves from machining.
The tricky part is to have a relatively easy machineable metal so that it allows for slow speed cutting which results in less heat.
When I had my internship in a metal-working company, we could cut down to half a millimeter thickness without bending the material. The trick is to cut the "cap" to rough dimensions (the "o-ring groove"), then cut it halfway away from the rod, and in the last step mill the center hole which would free the cap.
--
Ben
|
|
Reply To Message
|
|
Author: Chris P
Date: 2007-10-03 23:32
I replaced the tenon caps on an old Buffet (from 1938, as part of a full overhaul) with solid nickel silver rings instead of sheet metal ones as it was easier to turn them from solid nickel silver bar than to fashion them out of sheet metal. The top tenon ring was turned down and the metal ring fitted in it's place. The top tenon didn't have a ring originally, only the centre one (which was very loose) as this clarinet has an articulated C#/G# with the tonehole going through the tenon.
The upper tenon top ring (without a metal tenon cap) had been rounded off over time by either being badly fitted to the barrel socket or subsequent numerous tenon cork replacements and poor control when sanding the cork to shape (but this clarinet had been overhauled several times and the keys buffed heavily wearing through the Ab/Eb key cup at it's apex). The middle tenon ring was also removed in the same manner, but as it has an articulated C#/G# I had to clamp the tenon with a ring clamp so it wouldn't split when mounted between centres.
The outward appearance when finished looked like the original sheet metal ones with a ring of wood at the end of the tenon showing between the bore and the tenon cap, and I fitted them as socket rings in that they're an interference fit (using a press to put them on with) rather than being glued or burnished on - and all that was around 10 years ago and they're still very much secure on the tenons and haven't caused any noticeable constriction to the bore.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
|
|
Reply To Message
|
|
Author: perryg114
Date: 2007-10-04 13:57
For what is it worth Chris, if this was a clarinet worth saving I would ask you to fix it. It sounds like you know what you are doing.
Perry
|
|
Reply To Message
|
|
Author: rmr25
Date: 2007-10-06 14:39
Ferree's Tools (ferreestools@aol.com) sells tenon caps. Beyond that, here's a workaround I used on my grandchildren's broken tenons. First, find a discarded joint. with a good tenon that fits your instrument. Then, with a fine jeweler's saw, cut the tenon off flush with the joint body. Do the same with the cracked tenon on your Martin Freres. Next, make a round circular template out of thick paper that covers the tenon face you cut from the old joint. Mark three holes for the points of an equal-sided triangle centered on the surface of the template. Using a fine, 1 mm drill (can be found in Ferree's or hobby shops) drill down about 4 mm into the tenon surface. These three holes will be used for alignment pins made from ordinary stick pins. Next, use the template to drill three matching holes in the MF joint . These holes will receive the pins you placed in the tenon holes. Bond the tenon to the joint with high-strength epoxy. Hold things in place with a long threaded rod with wing nuts and washers. I used epoxy for bonding shafts to golf club heads; it withstands high levels of stress. The results in my grandkids' clarinets have been rock-solid.
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2007-10-07 04:27
I gave up buying off-the-shelf tenon caps a long time ago, because the ID or OD were almost always too large or too small.
Chris, where do you buy that nickel silver bar?
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2007-10-07 04:41
Clarnibass wrote:
Gordon, I read your method and couldn't understand some of it. It sounds like you are making a ring that is longer than needed, and then you press the extra over the end of the tenon? "
True. I 'press' the extra over BOTH ends of the lip, so it does not have a show of coming off. This is often also done for a the cork end of a machined cap, but the metal that is going to be 'pushed'; over has to be machined quite thin, and has to be annealed. (This is my answer to what I think you mean by " Is it better to have the cap right to the end of the cork groove, or leave some of the thicker wood and align the cap with it?")
" Also do you not remove any material from the tenon, and is this ring supposed to take the extra space already existing?"
I usually use this method when the tenon fit in its socket is too loose. Often I don't turn the tenon down. I do turn a 'lip' down if it is conical, oval, or otherwise distorted, or after building up chipped areas. I choose a thickness of silver to suit the gap between the socket and the tenon.
"Also if I turn from rod, is it better to leave thicker walls and then turn accurately after gluing it (in that case, how would you hold the clarinet on the lathe?) or maybe it is possible to bore a thicker rod, then turn the outside with something like machinist wax to make the thin walls?"
I use a steel cylinder, with one slit lengthwise, and walls about 3 mm, over the tenon, and inserted in the jaws of the lathe, to hold the clarinet in the lathe. (Much the same as a collet for shrinking sax necks.) Use a rotating centre at the other end. If I want the entire tenon free to work on, I use a contraption I made which allows the non-chucked end of the clarinet to be held in a fixed steady without damage to the timber, with the tenon projecting beyond.
|
|
Reply To Message
|
|
Author: clarnibass
Date: 2007-10-07 10:07
Thanks Gordon.
I was a bit scared of holding the clarinet between centers in case it puts too much pressure on the tenon (might break) but I guess as long as it's not too tight (and not too loose!) it should be ok.
For holding the joint to be able to work on the entire tenon, you use the same idea that I planned to use, which I learned from a local machinist. What contraption did you make? The method the local machinist showed me is to connect bearings to the bars of the steady rest.
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2007-10-07 14:14
For some reason, I have not had to use my contraption for the centre tenon yet. It was made for the bell tenon, where the outside of the timber is non-cylindrical. For the centre tenon I would make a different size of sleeve, or perhpas use sleeve only, machined to measure. I have simply wrapped robust (fibreglass?) tape around the body for the centre tenon, but this was only for skimming timber, not taking the strain of machining metal. Rollers on the fixed steady would be fine (but quite a mission to make) here, where the timber is cylindrical.
Not so easy to describe. I'll email a photo if you like:
It is based on a tapered roller wheel bearing from a motor vehicle.
I machined a groove in the outside of the outer race. The three contact points of the fixed steady tighten firmly into this groove, securing the alignment of the outer race. The outer race does not rotate within the fixed steady.
I made a brass sleeve to fit snug inside the bearing unit's inner race. The inside of the sleeve has a slight taper which jams nicely around the body timber just above the bell tenon. The sleeve has a small lip, increasing the OD at one end of the sleeve.
The fixed steady is set up to hold the outer race of the bearing concentric with the lathe axis, and to slightly press it towards the chuck. The bearing in turn centres the sleeve and presses its lip towards the chuck. The taper inside the sleeve, in turn, centres the timber of the clarinet body as it jams against the body, pressing it towards the chuck. The bearing turns freely, and there is no motion against the timber.
Such a contraption may not fit inside the fixed steady of a Sherline lathe, which I believe you have or are getting.
Post Edited (2007-10-07 14:20)
|
|
Reply To Message
|
|
The Clarinet Pages
|
 |
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
