cleats! we don't need no stinkin' cleats


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My apology to a great movie line but a violin came in today with a crack in the upper bout and when i took the top off it seems to have been an old crack that someone else had repaired poorly, the photos will show a nicely cleated repair that failed , the cleats did nothing to keep the crack closed of course they all popped off by just looking cross eyed at them, both these and the ones located on a repair in the lower bout, they looked good but in this case no cleats would have been better than these pathetic things.

 

instead of a simple crack repair i now have to undo the mess

 

 

post-28876-0-28905500-1412974218_thumb.jpgpost-28876-0-32522900-1412974236_thumb.jpgpost-28876-0-15690900-1412974253_thumb.jpg

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I find it hard to see why this repair would have failed. The cleats look like they have been extremely well fitted. I firmly believe that leaving large amounts of air space bewteen the plate and the cleat allows the plate to breathe and saves huge amounts of energy and time normally wasted by fitting a "proper" cleat.  I suspect in this case that the crack itself decided to work against the restorer in a desperate attempt to be taken seriously. After all it must be hard to be a crack. Everyone just wants you to disappear. Often cracks don't even have a choice when they are born into this world and then only to be scorned and reviled. Does gravity or shrinkage ever take the rap ? Sure they get a slap on the wrist but the crack is the real bad guy.

 

Enough already ! Next time you encounter a crack just leave it alone or make only minor non-invasive repairs like you see above so as not to disrupt the life of the crack. When you think about it isn't an F hole is just an artfully disguised crack.

 

All I am saying is give cracks a chance.

 

Peace out.

 

r.

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Rick

 

I may have to needle point that to hang in my shop, it brought tears to my eyes and a memory trip back to my Woodstock days.

 

And Jacob, it is my opinion that the large cross grain cleats do more damage in the long run, I can't count the times I have been faced with the new cracks running up the edge of the old cleats - or find buzzes from loose ones

 

if I feel the need to reinforce I opt for a diamond shape with the grain on the bias and the long axis aligned with the crack.

 

Reese

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Well, it is rather obvious that cracks can simply be cleated well, or not well. They can be repaired by someone that knows about wood and glue, or by an (excuse the term) idiot being paid minimum wage at Thrifty's Drug Store.

 

Well done (meaning well cleaned, well glued, and properly cleated ) cracks do not do this... well for some hundreds of years at least. A seam that runs down the center of a plate that, consists of two half plates glued together, well, think about it. Isn't it a well joined crack? In essence it is really a straight long crack that runs directly through the center of the plate.

 

So, what are we actually talking about with regard to cracks? How well they are glued? Why they're not going to work?

And why don't we talk about seams just like cracks?

All of these questions have obvious answers when you think about them. And the idea of cleats opening up a crack? Well if the seam has been properly repaired and the cleats are properly fitted and glued. There simply isn't a problem.

 

Now - cracks due to non seasoned, or perhaps 'green' wood being used - that's another kettle of fish all together. 

And to confuse the subject, is simply to make the answers (the proper answers) appear that they are tenuous or not workable.

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The force of a cross grained cleat is not NEAR strong enough to push open a well repaired crack.

It's expansion is so minuscule (and the expansion rate of the plate itself must be considered as well) and its resistance to the hide glue layer, and etc., etc.

The glue layer alone could as easily be SAID to force open a crack.

So, where do you go? What is the truth of the matter?

 

 - reality isn't quite like this.

If the plate is (was made of) seasoned wood, and the cleat is properly aged wood, and is well fitted, and well glued, and properly sized, and all the rest, this is the proper repair, and will last as long as is possible for a repair to last. 

 

There is no other way for anyone to repair a crack, than to either glue it, or to glue and cleat it.

Well made cleats are, and/or can be, very useful. Then again a well repaired crack may not require them. The choice is up to the repairman and his or her experience.

 

Much of the arguments coming up are utterly useless proclamations, Why? I don't know - it just seems like argumentation for the sake of chewing the bone beyond the marrow. (hah! I like that one - I'll have to remember it!)

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But it's the other way round - the cleat doesn't expand/contract, while the plate beneath it does.

If you scale up the pieces involved until you have something like a door, it's quite clear that glueing face grain together at 90 degrees will result in major problems, since the non-shrinkage of one piece in long grain inhibits the natural expansion and contraction of the other. This is after all why panels sit free in grooves.

This must also be true at the scale of a cleat .... either the glue fails or the cleat inhibits normal moisture-related movement.

And yet we need them.

So it makes sense to me to orient them off 90 degrees, and to make them as small as possible.

Mostly I believe that cleats are misused in crack repairs as a kind of flat platform that you can pull the sides of a crack down onto ....

If the crack is very finely aligned by other means, then the cleat should be pretty much superfluous, and I would think of it as a kind of bandage. 

 

ps. Craig, properly seasoned wood still exhibits contraction and expansion of up to 10% depending on atmospheric moisture content, exact wood species, whether it's fully on the quarter etc.

So the cleat doesn't expand and contract while the wood beneath it does. This really isn't deniable (!), so cleats have to be seen as a strange and generally workable compromise.

If you can point to an utterly useless proclamation I will withdraw it!

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If you can point to an utterly useless proclamation I will withdraw it!

 

Ok, I'll admit to argumentation for it's own sake then, myself.

 

I am arguing my own point of view and experience. Many years, and many repairs, and much looking and doing. I will not admit to being infallible and all knowing (though, I do often fool myself that I am a demi-god, all knowing and all powerful...ok, sorry...)  I may often argue a specific point to it's extreme edge of work-ability and practicality.

Often - like with this (the first)  photo - the utter amateurish nature of the repair and the probability of unseasoned wood and/or all the rest, make a sound and reliable answer impractical or impossible...

 

When there are, in fact, correct answers.

Answers that work reliably in the world today, that have to do specifically with violins, and wood in general.

So, there you go.

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And please Martin, take no offence.

 

I will argue anything with anybody, if it is about something that I think I know a little about.

I admire and respect your opinions, and your agreements and disagreements both. In my opinion, that's why we're here - to find and clear up things like this ...if possible.

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IMHO:

-Cleats are mainly meant to keep the crack from "flexing", thereby compromisingthe glued crack. NOT to hold the crack together, this is why I won't sometimes use cleats-no need to.

-Cleats are thinned out appropriately to reduce the problem of exp/cont (and dampening effect on the top due to lack of flexing)on cleats whose grain is 90 degrees.

-Dif between a center seam and a crack: infection(old glue or dirt), and lack of well fit surface as a crack is "torn" apart in relation to a well joined plate seam.  This is why it is so important to have a crack clean, and get it right the first time.

-I think rarely the plate will shrink to the point of the cleats opening up an old crack (though I have pics of one recently, but don't if this was because of a lously glued crack to begin with), but the problem is more of the edges of the cross grained cleats all lining up on a grain line that creates a new crack.   jeff

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And please Martin, take no offence.

 

I will argue anything with anybody, if it is about something that I think I know a little about.

I admire and respect your opinions, and your agreements and disagreements both. In my opinion, that's why we're here - to find and clear up things like this ...if possible.

Of course not.

I very much enjoy pushing ideas around with you, and I like the way you question things.

I got a bit pissed off with some other guy on the thread about back seam cleats, but that was because he blamed my apparent stupidity on my nationality (or on the fact that I wasn't American).

I think Jeff's post above is a great summation.

 

Many fine repairs on great old instruments have cleats which are extremely thin. Of course to do this you need a wood which is easy to split (to be sure there's no runout) and which is fibrous (to be sure the cleats are strong enough to serve their purpose).

Hence spruce and willow ...

:)

But I also like little parchment circles! As Jeffrey remarked elsewhere, big pieces seem to be able to ruin arching without necessarily inducing additional cracks.

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Nicely put Jeff.  I'm with you on the vast majority of your post.

 

But it's the other way round - the cleat doesn't expand/contract, while the plate beneath it does.

 

ps. Craig, properly seasoned wood still exhibits contraction and expansion of up to 10% depending on atmospheric moisture content, exact wood species, whether it's fully on the quarter etc.

So the cleat doesn't expand and contract while the wood beneath it does. This really isn't deniable (!), so cleats have to be seen as a strange and generally workable compromise.

If you can point to an utterly useless proclamation I will withdraw it!

 

Martin, with respect, I know that you've included the disclaimer of "wood species" and direction of the cut, but 10% movement is a pretty severe case, in my experience.  Maybe floating a violin in the river might get close to that, but my experience indicates the expectation of around 3% max. on a well seasoned quartered piece of spruce... and I've seen charts that seem to back that up.  Still significant enough to ensure that patches we must install at times run with, instead of against, the grain.

 

Yes, I think any "restoration" is a compromise.  I'd rather have a magic wand that returned the instrument to it's original condition.  

 

One advantage to cleat reinforcement is that it's reversible... another is that, correctly installed, they are effective.  I honestly don't think of many restorations as "permanent", but I regularly work on instruments that were restored 50-100 years ago that still have cleat reinforcements that are doing the job quite well.

 

It may well be that an appropriate line of cleats inhibit the expansion/contraction of the plate to which they are installed some small amount... directly at the location they are installed, but I don't think that if that occurs, it's much of a factor.  It is true, however, that a cleat installed just past the end of a running crack before cleaning, manipulating, and gluing the crack will prevent it from running further (during and after the repair).

 

I have had experiences with a few newer instruments in which spruce that was not well-enough seasoned was used.  In one case, a flank crack continued to open after repair and modest cleating (in the first year after repair).. but it wasn't the cleats that forced the crack open... it was drastic shrinkage of the top.  After re-repair which minimized the stress in the crack area, the top stabilized and has been fine or more than a decade since.

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Yes, 10% is severe ... :huh:

3% would be about right for quarter-sawn spruce not exposed to extremes, but an overheated house in the winter or an open air gig in Kuala Lumpur would represent extremes outside of that. Maple would be about double.

I suppose all that expansion and contraction turns into variations in the arching, so we don't perceive it as increases or decreases in width. On the belly this is perceived as changes in elevation - on the back where it's more extreme, it wouldn't be noticed except when it causes soundpost issues.

I think a 10% variation in the nominal width of a back is possible without actually flinging the thing in the river.

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Just to put this all in perspective... and not taking arching distortion into account, 10% would cause a 3.6" variation in in a 36" inch table top.  In fact, a good cabinet maker "might" allow for a 1" variation across the grain for a NEW top depending on wood species, direction of the split and the drying method (open air/kiln), and a nominal amount in length.  I worked for a conservator while attending violin making school.. and we used to pay quite a bit of attention to this sort of thing.  I'm back to floating the fiddle in the river.   :)

 

Returning to fiddles, the possible variation under the full length of a 1 cm cleat would be around .3 mm, max.  Isolate that to .5 mm on each side of the crack itself, that figure drops to .003 mm.

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I used to be a good cabinet maker - worked a lot with air-dried hardwoods, elm being particularly problematic. 

But mainly I was processing and drying wood, and making buildings out of green oak, where issues of shrinkage are immense.

I am probably unduly obsessed with wood movement and dimensional change.

 

Most climates don't experience relative humidity changes of 0 to 80%, and tables (and houses) don't move around the planet on a regular basis. But violins can, and some do ...

 

However, I agree, my perspective is unduly alarmist - just trying to point out that there are PRINCIPLES AT WORK HERE!

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Returning to fiddles, the possible variation under the full length of a 1 cm cleat would be around .3 mm, max.  Isolate that to .5 mm on each side of the crack itself, that figure drops to .003 mm.

Jeffrey, lets just say I'm a little confused here.  Would you please explain those figures a bit more?

 

Because of the daily RH cycling in my area, I'm seriously concerned with the subject.  I get to deal with the effects frequently.

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If a cleat is needed, then it is needed. The alternative of doing nothing is clearly worse. Therefore it is simply a matter of doing the best possible job under the circumstance. I believe that many an excellent restorer has illustrated their cleating concepts many times before here on Mnet if one takes the time to read older posts.

 

So perhaps the answers already exist here somewhere.

 

Search away and amaze your friends.

 

r.

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Quite often I have violins with a crack developing from the edge of the saddle upwards. i.e. heading towards the sound post area. I am in the habit of applying a cleat to make sure the crack does not extend. Any thoughts?

Saddle cracks, IMHO, usually start from a saddle with insufficient end gaps, so you have to fix that problem first.  Cleating the crack afterwards strikes me as good insurance.

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