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Clavette repair for broken button


catnip

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I am about to do a clavette repair on a student violin following the method posted a few years ago on Triangle Strings by Jerry Pasewicz. 

https://indd.adobe.com/view/b2d11313-d418-496b-8e01-c8a6b11e9a02

The article is well written and well illustrated.

This violin has a very thin back edge ~2.8 mm which does not leave much room for the traditional button graft.  I will be post images of the repair as it progresses. 

IMG_2868a.thumb.jpg.c6297388f4c5e7f54030df0b9b0da3a6.jpg

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So what would be advisable method for fixing button on student violin of no great value then? Throwing to dustbin?

I assume back removal plus patch plus new neck set and setup would cost more than a new student violin so this would be only worth doing on expensive instruments (or if insurance company pays).

I often fix cheaper instruments for beginners and finding optimal way that will make the instrument playable again and will not cost too much is crucial and it will give the instrument second life. In such cases thinking abut the "next guy" is not in place as next time someone breaks it the same way it will go to dustbin anyway but that chance is low as there are many dfferent ways the student can destroy instrument. :)

My quick fix of cheap instrument would be instead of doing "full" clavette, I'd just drill two parallel holes 4mm or so through the block where the clavette would go and insert clavette that is shaped with two matching projecting "pins" rounded to fit the holes. That would cut the cost to bare minimum and make the instrument playable again.

Just musing here, I've never done clavette myslef, just regular neck sets.

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35 minutes ago, HoGo said:

So what would be advisable method for fixing button on student violin of no great value then? Throwing to dustbin?

I assume back removal plus patch plus new neck set and setup would cost more than a new student violin so this would be only worth doing on expensive instruments (or if insurance company pays).

I often fix cheaper instruments for beginners and finding optimal way that will make the instrument playable again and will not cost too much is crucial and it will give the instrument second life. In such cases thinking abut the "next guy" is not in place as next time someone breaks it the same way it will go to dustbin anyway but that chance is low as there are many dfferent ways the student can destroy instrument. :)

My quick fix of cheap instrument would be instead of doing "full" clavette, I'd just drill two parallel holes 4mm or so through the block where the clavette would go and insert clavette that is shaped with two matching projecting "pins" rounded to fit the holes. That would cut the cost to bare minimum and make the instrument playable again.

Just musing here, I've never done clavette myslef, just regular neck sets.

Having done this x times, I dispute that doing a button patch takes any longer than a “clavette” due to the fact that one has no varnish retouching to do. Also should said violin come for re-repair in future years, it is easier to repair a violin that hasn’t been butchered already

https://maestronet.com/forum/index.php?/topic/351392-button-patch/&do=findComment&comment=964327

Banks button patch.gif

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11 hours ago, Michael Darnton said:

What Jacob says. Your "clavette" is only going to last until the next person saws through it taking the neck out for a set. One of the poorest "restoration" ideas of all time. Fix it right.

Please.

When sawing to remove the neck, one can make the saw cut above the clavette, leaving it intact. However, the clavette reinforcement is so much stronger than a button with a "bathtub patch" repair, that the joint between the neck and the clavette can likely be separated with a very thin opening knife, rather than by sawing.

A couple of other possible advantages:
1. No original wood is removed from the back or button, only from the upper block.
2. The clavette leaves a much stronger and more substantial piece of reinforcing wood, than a "bathtub patch" does.

There can be more ways of doing something "right", than the method one was initially taught. And sometimes, choosing between the various methods will come down to what seems best for the particular situation at hand, taking into account the many variables which can be present.

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48 minutes ago, jacobsaunders said:

The aim is to restore it's original strength, not  "strengthen it"

A "bathtub patch" will not restore a button to its original strength, unless the excavation has nearly vertical sides (which introduces problems of its own) or is deep enough to cut away some of the original purfling.

Question: If you reset a neck which was poorly fitted, with the resulting gaps bridged with glue, will you preserve or re-create those gaps to avoid making the neck joint stronger than original?

Repair and restoration choices are not always simple and one-dimensional. Giving them some thought can be advantageous. Even re-gluing an open seam is not always the same, if one wants to do an exceptional job.

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56 minutes ago, David Burgess said:

When sawing to remove the neck, one can make the saw cut above the clavette, leaving it intact. 

If we can come to some universal convention so that we know that it's a clavette instead of a piece added to the heel, which is FAR more common and normal, what most people will expect. Painting it red, perhaps? 

Otherwise it's similar to storing your paint thinner in a juice bottle in the fridge without changing the label.

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31 minutes ago, David Burgess said:

A "bathtub patch" will not restore a button to its original strength, unless the excavation has nearly vertical sides (which introduces problems of its own) or is deep enough to cut away some of the original purfling.

Question: If you reset a neck which was poorly fitted, with the resulting gaps bridged with glue, will you preserve or re-create those gaps to avoid making the neck joint stronger than original?

Repair and restoration choices are not always simple and one-dimensional. Giving them some thought can be advantageous.

Yes it will if you excavate you're bath tub down to the purfling. I do not subscribe to the urge to “strengthen” violins, I just repair them. If you filled you're Burgess violins out with epoxy foam, they would be stronger too. Perhaps a good idea

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I always thought that a modern neck heel fitted and glued properly into the mortise (what’s not the same as dovetailing ;)) is strong enough to hold the neck under the usual circumstances and the button just adds some more stability. This should make any attempt to improve or strengthen an original bottom thickness superfluous.

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29 minutes ago, Michael Darnton said:

Otherwise it's similar to storing your paint thinner in a juice bottle in the fridge without changing the label.

 If one does that, I would recommend giving it a sniff before taking a swig. ;)
What Pasewisz does (which is specified in the online instructions) is to deliberately mismatch the grain direction of the clavette with that of the heel, to provide a strong clue that this is not a conventional heel extension.

I also think it's a nice idea to furnish the owner of an instrument with a summary of past repairs, which can be used to assist repair people in the future.

23 minutes ago, jacobsaunders said:

Yes it will if you excavate you're bath tub down to the purfling. I do not subscribe to the urge to “strengthen” violins, I just repair them.

Uh, no. If you only go down to the purfling, the patch you have illustrated will not be as strong as the original unbroken wood, since it has much less area that the original un-broken wood.  Perhaps it would be as strong if you used carbon fiber for the patch, rather than wood? ;)

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26 minutes ago, Michael Darnton said:

If we can come to some universal convention so that we know that it's a clavette instead of a piece added to the heel, which is FAR more common and normal, what most people will expect. Painting it red, perhaps? 

Otherwise it's similar to storing your paint thinner in a juice bottle in the fridge without changing the label.

What about using a different wood for the clavette? Cherry for example. That should be a clear indication that something is going on there, and if it ends up as searchable, it could become “standard” for less valuable instruments.

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6 minutes ago, David Burgess said:

 

Uh, no. If you only go down to the purfling, the patch you have illustrated will not be as strong as the original unbroken wood, since it has much less area that the original un-broken wood.  Perhaps it would be as strong if you used carbon fiber for the patch, rather than wood? ;)

Yes! The cross section (and strength) of a bathtub patch is probably less than half of an unbroken button.

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9 minutes ago, Blank face said:

I always thought that a modern neck heel fitted and glued properly into the mortise (what’s not the same as dovetailing ;)) is strong enough to hold the neck under the usual circumstances and the button just adds some more stability. This should make any attempt to improve or strengthen an original bottom thickness superfluous.

Then why reinforce the button at all after gluing it back on? Not reinforcing it is another option to consider, which in some scenarios, might be a viable choice.

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2 hours ago, jacobsaunders said:

Having done this x times, I dispute that doing a button patch takes any longer than a “clavette” due to the fact that one has no varnish retouching to do. Also should said violin come for re-repair in future years, it is easier to repair a violin that hasn’t been butchered already

With cheap student violins, retouching is sometimes superfluous, just a swipe of appropriately colored spirit varnish will often be good enough. Violin that is worth the retouch is likely worth of doing patch as well. For such violins any time-consuming re-repair is not considered. Just simple quick glue-back-together methods are applicable.

If not certain, then simple reglue-all-together is not going to do any harm, if it fails prematurely, one can decide to do a patch or whatever reinforcement.

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29 minutes ago, David Burgess said:

Then why reinforce the button at all after gluing it back on? Not reinforcing it is another option to consider, which in some scenarios, might be a viable choice.

We had this argument some years ago, and I’m afraid that I’m not motivated enough to have it again. The main point is that it is not necessary to scar a violin for life, just because a part got broken, and it is easily possible to repair it invisibly, so that it is good as new. People who have the urge to “strengthen” old violins, should have their fingers chopped off

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52 minutes ago, David Burgess said:

Then why reinforce the button at all after gluing it back on? Not reinforcing it is another option to consider, which in some scenarios, might be a viable choice.

You might need a certain stability of the button for both fitting the heel and glueing/clamping it.

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1 hour ago, jacobsaunders said:

People who have the urge to “strengthen” old violins, should have their fingers chopped off

Maybe. But you still haven't responded to the question I asked you earlier:

"If you reset a neck which was poorly fitted, with the resulting gaps bridged with glue, will you preserve or re-create those gaps to avoid making the neck joint stronger than original?"

What I'm trying to illustrate is that a rote, "paint-by-the-numbers" single approach to a repair or restoration  situation is not always optimal. There are some stunningly innovative and creative high-level repairers and restorers running around these days. I like to continue to learn from them. That's one of the reasons I've been involved in the Oberlin Restoration Workshops for about 20 years straight. :)

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31 minutes ago, David Burgess said:

Maybe. But you still haven't responded to the question I asked you earlier:

"If you reset a neck which was poorly fitted, with the resulting gaps bridged with glue, will you preserve or re-create those gaps to avoid making the neck joint stronger than original?"

What I'm trying to illustrate is that a rote, "paint-by-the-numbers" approach to repair or restoration is not always ideal.

There is no need to answer stupid questions, just because someone is taking the piss

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2 hours ago, jacobsaunders said:

There is no need to answer stupid questions, just because someone is taking the piss

Do you sit or stand when taking a piss in your home toilet? I have seen good arguments for both methods, but perhaps you have some dogmatic decree about how pissing must be done? ;)

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