tárogató Remanufactured 2C Tenons and Rings

jbtsax

jbtsax

Distinguished Member
Distinguished Member
I am starting a new thread that will address work on the tenons and rings so that the other threads on body modifications will not become too cumbersome.

Because the black paint-like substance was removed and the wood has experienced some shrinkage from drying out, the rings ended up being extremely loose. After a few failed attempts to put some type of shim material under the rings, it was decided that cutting and resizing them would make them look better and be more secure.

The first photo shows the gap beneath the bell ring which was originally held in place by four small nails.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Fitofbellring-1.jpg

The second photo shows the ring after being cut down in size and braised back together.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Bellringcuttosizeandbrazed-1.jpg

The next photo shows the small top ring before being cut and braised.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Smallringbeforecuttingbrazingandpolishing.jpg

The last photo in this series shows all of the rings in place after being cut, braised, filed, sanded, polished and nickle plated.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Allringssizedandplated-1.jpg

One area of the project that took more time than I anticipated was the fitting and reinforcement of the tenon joints. The standard is to have the joint fit snugly with little or no wobble before the tenon cork is installed. The procedure used required carbon fiber threads shown below, 15 minute epoxy, and lots of patience.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Carbonfiber2.jpg

The best method I found was to pull the carbon fiber thread through a puddle of epoxy to coat it thoroughly and then wrap it around the area needing to be reinforced or built up. The first photo in this series shows the preparation of the top joint tenon by wrapping the areas to protect with teflon tape and adding a delrin cap covered with teflon tape at the end.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Toptenonprepedtowrapwithcarbonfiberf.jpg

The second photo shows the epoxy coated carbon fiber thread being wrapped around the tenon in the channels created by the layers of teflon tape and the delrin cap. It is extremely important to use rubber gloves when handling the carbon fiber thread and not to get any near your face or clothing.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Wrappingtoptenonwithcarbonfiber.jpg

Here is the tenon after the wrapping is completed.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Toptenonafterwrapping.jpg

Once the epoxy has set at least 24 hours, the tape and cap are removed and the carbon fiber is filed, sanded, and scraped down to the required diameter. This step is where having a lathe would have saved a huge amount of time and provided a more accurate job. The next photo shows the finished top tenon after the tenon cork has been installed.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Finishedtoptenon.jpg

The next series of photos show the identical process used to size and reinforce the male middle tenon joint.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Teflontapeontenon.jpg
http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Tenonafterapplicationofcarbonfiberandepoxy.jpg
http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Finishedmiddletenon.jpg

There were many cracks in the lower joint female tenon under the ring. This area too was reinforced with carbon fiber and epoxy to add strength and to close the cracks.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Femaletenonreinforcedwithcarbonfiberunderring.jpg

Another problem that needed addressing at the middle tenon joint was the gap between the end of the upper joint male tenon and the bottom of the female socket in the lower joint. That gap is shown in the following illustration which I also posted in another thread on this general topic.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20tenons%20and%20miscellaneous/Tarogatomiddletenon.jpg

To make an insert, a Forstner bit was used to hollow out a circle in a tapered table leg the approximate inside diameter needed at the location on the leg having close to the correct outer diameter.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20tenons%20and%20miscellaneous/Taperedtablelegusedtomakedisk.jpg

The "ring" shown below was cut off using a miter saw to slightly thicker dimension than needed.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20tenons%20and%20miscellaneous/Spacerdisk.jpg

It was then carefully filed and sanded to fit snugly inside the bottom of the female tenon. The next photo shows the "spacer ring" after being stained inserted into place. It will eventually be held in place with epoxy.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20tenons%20and%20miscellaneous/Diskinstalled.jpg

To reduce friction and keep the tárogató's new flat springs in their "tracks", stainless steel inserts were made to fit into the body along the path of the spring's motion. To make the inserts, the grip portion of a single edge razor blade is opened with a small screwdriver and removed. Along the exposed portion of the blade a line is etched using a scribing tool at the width needed for the insert. The portion to be used is then put in a vise with the etched line just showing and the portion exposed is hit sharply with a steel hammer. If done correctly, the steel razor blade snaps off at a perfect straight edge right at the line etched into the metal. Cutting the piece to length can be done with a good pair of wire cutters. If needed the corners can be rounded using safety glasses and a sanding disk holding the steel with a pair of vice grips. Below is a photo of how they turned out. The inserts can also be seen in some of the photo's above. They are glued into place using gap filling CA.

http://i162.photobucket.com/albums/t251/jbtsax/tárogató%20rings%20and%20steel%20inserts/Stainlesssteelinsertsforflatsprings1.jpg

This basically ends the visual presentation of the extensive work that has been required to re-manufacture a crudely made Romanian tárogató to bring it closer the the standards of modern instruments. There are still a host of imperfections, but it is a lot closer to being a playable woodwind than it was when the project began. All that is left to do is the installation of pads, key corks, and other linking and silencing materials. Once the pads arrive, they will be installed and the keys adjusted so that the instrument can be played for the very first time in its new state. At that point I will post a few pictures of the completed instrument and hopefully be able to learn to play well enough to provide a recording of how it sounds.

I have purposely left doing anything with the rough cut bore of the instrument other than oiling until after I have had a chance to play it and assess the tone and intonation. That could be the fruit of an entirely new topic under acoustics. ;) We will cross that bridge when we get to it.
 
Really impressive work John! One thing worth noting is that even my Stowasser is crudely made compared to modern instruments, or even good instruments of the period. Much better than that Romanian tárogató, but with somewhat uneven tonehole seats, etc. Since it does seal well, I am leaving it alone, but comparing to even a student clarinet, one can see the difference.

One thing that is interesting about the Stowasser is the extreme thinness of the wood. It is barely thick enough (in the lower joint) to accomodate the screw-in posts: in fact you can see a bump in the wood on the inside at the position of every post, where the wood has been pushed out by the insertion of the post. No wonder so many of these instruments suffer severe cracking!

Another interesting point is the fact that the ring keys (on any tárogató AFAIK) actually have flat tops to the holes, as is standard with clarinet and oboe ring keys. All are simply drilled directly in the wood, with a collar cut out for the ring key clearance.

I hope that the effort has been worth it for you. It certainly looks like you gained some valuable knowledge and skills. I hope at the end you enjoy playing it.

On the Stowasser I found several notes to be sharp. The top ring key hole and the third ring key hole were too large, so that forked C and A were 10-20 cents sharp. Also the side Bb was very very sharp compared to using the inline Bb key: it looks like that hole was enlarged for some reason by a previous owner. I had very good luck making crescents from epoxy putty, colored to match the wood. I suggest that if you find tuning problems, which would not be surprising, you consider this method for tuning sharp notes. This is a technique that is standard in tuning shakuhachi flutes.
 
kymarto said:
One thing that is interesting about the Stowasser is the extreme thinness of the wood. It is barely thick enough (in the lower joint) to accomodate the screw-in posts: in fact you can see a bump in the wood on the inside at the position of every post, where the wood has been pushed out by the insertion of the post. No wonder so many of these instruments suffer severe cracking!
Click to expand...

Ditto on mine (the Hungarian one). Bumps all over the place. Interestingly, not so on the Timis - they left more wood there. On my Hungarian, the thumb rest screws are loose and the whole thumbrest wiggles. Would filling the holes with CA and re-drilling be considered a hack, or a solid fix? I'm even considering moving the thumbrest a bit closer to the Bb thumb key - for reasons already discussed. And again, surprisingly, they were more clever with the Timis - the thumbrest screw positions are perpendicular to the length of the instrument, not in line with it like on my Hungarian model. And the thumbrest has a wider plate that wraps the body more. It's just more stable.

George
 
It appears from the photos I've seen that the Romanian tárogató I have been working on is a copy of the Stowasser instruments, albeit a rather poor copy to say the least.

The thinness of the body made pinning the crack at the upper portion of the lower joint next to impossible, so wrapping the tenon with carbon fiber under the ring after filling the crack with thin CA seemed the way to go.

Once the bottom joint was finished I plugged the toneholes with rubber stoppers checked the body for leaks with the magnehelic set at 8 inches of water pressure. It leaked like a sieve. Upon immersing the body in a tub of water it was found that the main leaks were coming under the thumbrest. It turns out that the nails originally holding the thumbrest in place had gone all the way through to the bore, and the much shorter screws used to replace the nails did not seal the leaks at all.

Once those leaks were sealed using gap filling CA, I found smaller leaks in area of the crack. Those leaks were fixed by applying ultra thin CA to the area and creating a vacuum inside to "suck" the glue into the cracks.

That is when the now nearly airtight body revealed tiny bubbles of air coming to the surface of the wood through the body itself by way of its obvious porosity. This bubbling effect virtually went away when the input air pressure was lowered to the more realistic 4 inches of water. I believe it was John Coltman who wrote in a study of the porosity of bassoon pads, that the sound pressure inside a woodwind approximates the air pressure of 1 inch of water.

Even though this leakage through the porosity of the wood itself probably will not affect the playability of the instrument, it does suggest an answer to the question of why the much denser grenadilla is chosen over the more beautiful rosewoods in the manufacture of woodwind instruments. It is probably more stable and easier to cut to exacting specifications using sharp tools, as well as being more "airtight".
 
jbtsax said:
It appears from the photos I've seen that the Romanian tárogató I have been working on is a copy of the Stowasser instruments, albeit a rather poor copy to say the least.

The thinness of the body made pinning the crack at the upper portion of the lower joint next to impossible, so wrapping the tenon with carbon fiber under the ring after filling the crack with thin CA seemed the way to go.

Once the bottom joint was finished I plugged the toneholes with rubber stoppers checked the body for leaks with the magnehelic set at 8 inches of water pressure. It leaked like a sieve. Upon immersing the body in a tub of water it was found that the main leaks were coming under the thumbrest. It turns out that the nails originally holding the thumbrest in place had gone all the way through to the bore, and the much shorter screws used to replace the nails did not seal the leaks at all.

Once those leaks were sealed using gap filling CA, I found smaller leaks in area of the crack. Those leaks were fixed by applying ultra thin CA to the area and creating a vacuum inside to "suck" the glue into the cracks.

That is when the now nearly airtight body revealed tiny bubbles of air coming to the surface of the wood through the body itself by way of its obvious porosity. This bubbling effect virtually went away when the input air pressure was lowered to the more realistic 4 inches of water. I believe it was John Coltman who wrote in a study of the porosity of bassoon pads, that the sound pressure inside a woodwind approximates the air pressure of 1 inch of water.

Even though this leakage through the porosity of the wood itself probably will not affect the playability of the instrument, it does suggest an answer to the question of why the much denser grenadilla is chosen over the more beautiful rosewoods in the manufacture of woodwind instruments. It is probably more stable and easier to cut to exacting specifications using sharp tools, as well as being more "airtight".
Click to expand...

Wasn't there a thread recently about curing leaks through the wood by oiling the bore? Or was that on the musical instrument technicians yahoo group?

Yours, confused, from Bavaria.
 
Believe it or not, the Stowasser is much thinner than your instrument, John. Scarier than hell. The Reményi is about twice as thick at the lower tenon. It does seem to me that oiling the bore would help seal it.

George: I might suggest epoxy putty instead of CA to fill and retap those holes. It seems to me (tho I'm not sure) that it is less brittle. I would definitely do it if I were you. Before you move it--if you do--make sure the position would not be uncomfortable in the long term. If not, seems like a good idea.
 
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