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Bass bar crack repair


FiddleDoug
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First: I recognize that a bass bar crack is a serious crack, and will devalue an instrument. I'm also well aware, and have done, the standard repair for a bass bar crack. The usual repair consists of removing the old bass bar, gluing the crack, fitting a new bass bar, cleating the crack, fitting the new bass bar over the cleats, gluing the new bass bar. All in all, a time consuming, and expensive repair.

Now let's get to the circumstances: This is a decent German instrument, imported and labeled by Gemunder, in NY. The instrument was owned by my client's father, and was found in the house after my client's parents passing. My clients are not well off, and don't play the violin, although her brother might want to learn.

The instrument is in nice shape except for this bass bar crack. The crack appears to have started as a shrinkage crack (like a saddle crack), and extends right along the outside edge if the bass bar for about 4 inches.

I brought this up quite a while ago, and a couple of readers suggested "just glue it, it might hold". I decided to go a little further. My repair consists of, with the top removed, gluing the crack, placing a cleat just below the end of the bass bar, gluing a linen strip, 1/2" wide and about 3" long, along the plate/bass bar joint (half on the bass bar and half on the plate). Much less expensive for my clients.

My logic on this: The stress on this crack is much less than a soundpost crack. It doesn't have the single point hinging action that soundpost pressure gives. The bass bar acts as a support beam under the bridge foot. The linen strip along the full length of the crack should give very good support. The thin strip of linen along part of the bass bar shouldn't change the mass or action of the bass bar much. The repair is totally reversible!

Your thoughts please.

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Hmmm. The main possible problem I can see is you don't have a solid join between the two sides of the split. If you think of the number of vibrations coming from the bridge foot onto the bass bar, you have an awfully large number of shear stresses being applied continuously. What you are proposing if I read it correctly is to put an angle-bracket under the split a bit like a shelf-support? It the glue-soaked linen is strong enough and doesn't shake to bits over time it might work. However if there are tiny gaps between the bar and the table you might also get buzzing or other odd effects.

My own preference would be to join the two halves with wood as usual. But if money is a consideration then IMHO there's no harm experimenting as long as you explain to the client why you've done what you have, and that you'll put it right (but at cost) if it fails in the near future. They have the choice of how they want the job done that way.

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I thought about these concerns.

Mayo, The bar remained solidly glued, with no gaps. Linen/canvas is well known historically, but not in this particular context . Stradivari used it to reinforce cello ribs.

Andrew, I thought about cutting notches into the bass bar for cleats, but the time involved, and the continuous support of the linen strip sent me in this direction.

Thanks for your input.

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I thought about these concerns.

Mayo, The bar remained solidly glued, with no gaps. Linen/canvas is well known historically, but not in this particular context . Stradivari used it to reinforce cello ribs.

Andrew, I thought about cutting notches into the bass bar for cleats, but the time involved, and the continuous support of the linen strip sent me in this direction.

Thanks for your input.

Yep, sure I know it was used historically on ribs but perhaps I'm misunderstanding the damage. I thought it was a crack in the top that would act in a similar way to a shelf of earth rising higher than another when an earthquake occurs (albeit on a microscopic scale). Being right next to the epicentre of the quake if you like, it would have to take a good vertical hammering from the bridge foot. Whereas the ribs would not have such extreme forces being further away and with the crack at 90 degrees to the table (yes, they would vibrate in a plane to the cracks as well but not so badly).

That was my thinking, I'm probably wrong but you did ask for thoughts :-)

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Mr. Wall,

I would think some "L" patches or cleats (whatever your preferred terminology is) would be the safe way to go. I've seen these on some rather old repairs with few problems.

--Chris

Chris

adjoining the bass bar?

I have never seen this done. Could you describe them further please? I wonder if I am thinking the right thing.

Thanks

Craig T

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Mr. Wall,

I would think some "L" patches or cleats (whatever your preferred terminology is) would be the safe way to go. I've seen these on some rather old repairs with few problems.

--Chris

I have recently seen major problems with just the kind of "L" cleats you described. A cello had a nasty buzz that would come and go for the past 30 years of it's life. When we removed the "L" cleats we found that the bassbar was loose from the top right under these cleats.

I think a better alternative re-enforcement would be to inlay cleats into the existing bar. Chisel away the bar about 1.5mm to 2.0mm high to fit the cleat stock. Glue the cleat into the excavation in the bar and shape as normal. This will work as long as there is no tension in the bar.

Jerry

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An “L” patch... I think they’re talking about using a ‘90’ degree triangle that would rest on the bass bar and the top... eh.

Even if the customer doesn’t have a lot of money, can they afford to have the repair done a second time? I know that it’s best to do the least intrusive repair first, and while it might be worth a shot here (hard to tell without photos), I would just remove the bar, cleat the crack, and then fit the bar over the cleats.

I did a similar procedure on a cheap German violin, was one of my first repairs two years ago. The time spent really wasn’t that much longer than fitting a normal bar. It’s persnickety work, but what’s new? In retrospect, keep the cleats simple (so that they're easy to fit over), and cut them down later. This would have been a much neater repair if the violin hadn't been played for years with an open bass crack.

resume_04.gif

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Iburkard,

Just curious, what would you charge for a bass bar replacement? Anyone else, your usual charge for a bass bar replacement? Remember that I'm trying to keep the cost reasonable for the client. I've already removed the top, and will be fitting new pegs, strings, bridge, tailgut, etc.

Jerry,

I considered excavating for a couple of cleats, and may still do it.

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The material required is inexpensive; your time is the expense. If you feel that it will take you and an unreasonable amount of time to replace the bar, don’t. If you can wrangle the fix without going Weisshaar, you should be fine.

I can’t tell you what to charge someone, but it sounds like you want to be nice and give these people a deal. If you want to be kind, just do it for the experience of the repair, record how long it takes, and charge accordingly in the future. Some people will say that this is no way to run a business. Luckily, I don’t run one.

The idea of excavating is interesting, and you can probably pillar around the bar, and pull the crack closed, but working around the bar (and into the bar) might be more time consuming than just taking it out… and you probably won’t get as clean of a fit, unless you’re Jeffery.

If it’s your lucky day, you may even be able to remove the bar cleanly… do your work… and put it back.

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Yes, you've hit the nail on the head! Time is expensive, and limited! If you look up the cost of replacing a bass bar, you'll find it at about $250 or so in many shops.

I've done bass bar replacements, and it probably takes me 3 hours or so, with everything included. Even at my low overhead rates, I'd have to charge $100 just for the bass bar. Opening and closing the instrument, crack repair, varnish touch up, and set-up are on top of that.

The crack was a clean one, immediately adjacent to the outside edge of the bass bar. It closed cleanly, glued almost invisibly with hide glue, and looks solid. I may still excavate a couple of slots for cleats, but the linen should be fine.

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An “L” patch... I think they’re talking about using a ‘90’ degree triangle that would rest on the bass bar and the top... eh.

Even if the customer doesn’t have a lot of money, can they afford to have the repair done a second time? I know that it’s best to do the least intrusive repair first, and while it might be worth a shot here (hard to tell without photos), I would just remove the bar, cleat the crack, and then fit the bar over the cleats.

I did a similar procedure on a cheap German violin, was one of my first repairs two years ago. The time spent really wasn’t that much longer than fitting a normal bar. It’s persnickety work, but what’s new? In retrospect, keep the cleats simple (so that they're easy to fit over), and cut them down later. This would have been a much neater repair if the violin hadn't been played for years with an open bass crack.

resume_04.gif

+++++++++++++++

Nice job.

I think the subsequent owners for generations whom you would never know, would appreciate too.

If someone open the violin 100 years later and the person would say " Wow, what a good work, forever thankful"

(as some commercial says" Priceless")

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An “L” patch... I think they’re talking about using a ‘90’ degree triangle that would rest on the bass bar and the top... eh.

Even if the customer doesn’t have a lot of money, can they afford to have the repair done a second time? I know that it’s best to do the least intrusive repair first, and while it might be worth a shot here (hard to tell without photos), I would just remove the bar, cleat the crack, and then fit the bar over the cleats.

I did a similar procedure on a cheap German violin, was one of my first repairs two years ago. The time spent really wasn’t that much longer than fitting a normal bar. It’s persnickety work, but what’s new? In retrospect, keep the cleats simple (so that they're easy to fit over), and cut them down later. This would have been a much neater repair if the violin hadn't been played for years with an open bass crack.

Hi iburkard,

Very nice repair work considering how long it had been open. I see that you install your cleats on the diagonal. Is there a reason for this or is it just personal choice? The only cleats that I have seen so far, have been on the square with the grain of the cleat running at 90 degrees to the top grain.

Also in your 2nd pic you have what appears to be a box like frame with clamps. Is this what you used to pull the crack together?

Tony

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I was wondering that myself what an "L" patch looks like?

Just a daft idea but I'm wondering if it would be possible to bend a thin piece of spruce at a sharp enough angle to make a cleat or is that what an L patch is?

Are you also trying to imagine what the grain orientation would be, if the patch was cut in an L shape, joining the bass abr and plate?

The idea of a bend, or even a triangular notch with a bend, might work...

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keep the cleats simple (so that they're easy to fit over), and cut them down later. This would have been a much neater repair if the violin hadn't been played for years with an open bass crack.

Nice repair iburkard - thank you for the documentation.

I too like to put the cleats on tall, glue them in, and then trim them down after they are dry.

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I thought at the time that the cleats might expand and sheer the top grain, and that going completely against the grain might make the repair too rigid (like plywood, and prevent the plate from flexing/vibrating... not that this VSO will ever responsively vibrate). I now understand that the amount of expanding (down the grain of a cleat) is very very minimal. I still like to think that tilting the cleat allows a little more flex, but I am not experienced enough to say. I wish that I had placed the cleats, underneath the bar, at a perfect 90 to make fitting the bar easier.

the cleats were staggered down centerline... ////-----\\\\-----////-----\\\\

The box behind the second image is actually just a padded stool. If you look closer, there is a heavy clamp on the floor holding up another medium sized clamp. There were two pillars on each side of the top crack, pulling it together. The larger clamp is doing a hack job, holding the top plate surface level. If you wanted to do this correctly, there should be a form/cradle assisting.

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Are you also trying to imagine what the grain orientation would be, if the patch was cut in an L shape, joining the bass abr and plate?

The idea of a bend, or even a triangular notch with a bend, might work...

Grain direction is the thing really. I imagined you would have end grain glued to the bar which doesn't sound good. Maybe it would work rotating it to 45 degrees. A variation on the bent spruce could be a couple of layers of shavings if you were feeling lazy.

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Concerning the original post:

The idea it's not an instrument that's worth the effort and cost of a " time consuming, and expensive repair" is completely understandable... but, I have an alternate logic thread for consideration.

If a repairer/restorer's reputation is built on the existing body of work, then it might be wise to base the cost/benefit by determining if the instrument is "worth" the effort to repair it properly. While the argument might be made that a repair on the cheap "at least it keeps the instrument in circulation", the stuggle lies in determining if this is something you really want to be known for.... In other words, is it worth your reputation to keep the instrument "in circulation" and be the hero for the day ('cause when the repair fails, you're probably going to get the "credit" for it)?

As far as linen, L cleats, and other shortcuts goes, my experience is that they fail eventually. In the case of linen, the shrinking of the material may also have the potential to cause some distortion in the flatter areas of the arch. The two methods I've seen last best (that are least invasive) are new bar with cleats installed under it, and insetting cleats into an existing bar. Some care should be taken to make sure the ends of the cleats don't terminate on the same grain line...

Some photos from an older post on the subject (cleats under new bar; the other repair work was pre-existing):

cleating.jpg

one.jpg

single.jpg

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