Warped student cello bridge -- repair or replace?

[Carrion]

My 5th grader's Eastman cello -- bought last year on Craigslist for $350 -- has a bridge that's warping.  I've read some threads here about how to straighten it out and planned to try one of those methods, but it seems like there's a good chance it will warp again at some point.  That might be fine, but I'd like to fix it as best I can.  It looks like I can buy a replacement bridge -- like from Despiau, which the original is, from resellers -- but I think that is a blank that needs shaping.  Pre-shaped ones are also available on eBay and elsewhere. 

Any advice on which avenue I should take?  I'm torn on wanting to do the reshaping as a wood project (at which I have little experience but plenty of patience) and wanting to just get it done.  Open to taking to luthier but I'm not sure it's worth it.  Thanks. 

[Michael Darnton]

Contrary to what other advice will be, I ALWAYS straighten cello bridges and have never had a problem with them rewarping, BUT I alway figures out why it happened and correct that. If you don't it will happen again. Usually it is because of neglect, but often the problem is that the bridge naturally wants to stand at one angle and the player wants to pull it to another. So the cure is to refit the feet, or correct the player. Then it will never happen again, in my experience. I have done this many, many times successfully.

Often the problem is that cellos absolutely invariably tend to collapse a little right away when they are strung up, then a little more over time, always tilting the bridge north. I have never seen a cello that did not do this. Set up people often don't realize this so the result is a bridge that wants to lean north a bit from where they set it, if they set it right at all. Then the player will pull it back where it should be and the result is what you have. You may not see it right away, so that's why setup people miss that. The feet do what they need to do to stay flat and then the top of the bridge bends to accommodate where the player wants it. In your case I think that's what happened and I am going to guess that you need to recut the feet so that it is leaning "back" more.

Straightening: fold a paper towel to about 2.5x2.5 inches, soak it wet, put it on the plate in your microwave, put the bridge concave down on the towel, and nuke it in 15 second increments. You can correct local warpages by where you place the towel/water. Go for an over straightening, then stand the bridge up and nuke it in 10 sec increments until it is dry.  Nearly dry--if you go too far you will burn the bridge, and that starts on the inside where you can't see it and it's too late.

If the bridge can't be fixed by steaming, you will have to bring in dry heat, like the bottom of an iron skillet, and bend/set it with dry heat. That's harder.

Straightening is easy, but correcting the cut of the feet is hard. You probably realize that you may not have the chops for that and if so should rely on a professional.

[Bill Merkel]

51 minutes ago, Carrion said:

I think that is a blank that needs shaping.  Pre-shaped ones are also available on eBay and elsewhere. 

It would probably be better as-is than fitting (actually 'making') one yourself from a blank, or using self-fitting ones.  Could actually be better or worse than a new one fitted by a professional.  String instruments are funny like that.  MD above knows what he's doing, is a genuine big deal in violin world, if you have no way of knowing.  I would definitely try his advice, following exactly

[Woodland]

I second Michael's advice as far as steaming vs. replacing, it's totally worth straightening. I'm guessing that's an Eastman Model 80 cello (looks like one), they're usually fitted with Despiau D-grade bridges at Eastman which are ok rental-grade bridges, but weaker wood. Combining that with rough handling by students we see that problem in our shop weekly. If you have a string shop in your neighborhood I'd recommend letting them handle it. It will be more economical than having someone cut a new one when it really isn't necessary.

[Brad Dorsey]

4 hours ago, Michael Darnton said:

…Often the problem is that cellos absolutely invariably tend to collapse a little right away when they are strung up, then a little more over time, always tilting the bridge north. I have never seen a cello that did not do this. Set up people often don't realize this so the result is a bridge that wants to lean north a bit from where they set it, if they set it right at all. Then the player will pull it back where it should be and the result is what you have. You may not see it right away, so that's why setup people miss that…

When I set up a cello (or a violin), I fit the bridge feet so than the bridge sits on the top with the face towards the tailpiece making a right angle with the top, which means that the angle towards the fingerboard is somewhat larger.  Does this sound right?

[donbarzino]

I agree with Michael about bridges tending to warp up north towards the scroll and I believe this is from

a player tuning again and again over time as the strings stretch and never stopping to look and straighten their bridge.

When a bridge warps the opposite way, as in the OP's instrument, I believe this is caused by putting the instrument away for a long while with the strings fully tuned. Since it is many times longer than the lower portion of the strings between the bridge and tailpiece, the playing portion of the strings stretches proportionally more over time and the bridge,

being anchored to the strings, tilts backward. It would be interesting to know how, if at all, this instrument was used

leading up to this situation.

[Carrion]

41 minutes ago, donbarzino said:

I agree with Michael about bridges tending to warp up north towards the scroll and I believe this is from

a player tuning again and again over time as the strings stretch and never stopping to look and straighten their bridge.

When a bridge warps the opposite way, as in the OP's instrument, I believe this is caused by putting the instrument away for a long while with the strings fully tuned. Since it is many times longer than the lower portion of the strings between the bridge and tailpiece,  the the playing portion of the strings stretches proportionally more and the bridge,

being anchored to the strings, tilts backward. It would be interesting to know how, if at all, this instrument was used

leading up to this situation.

I've only had it since the summer, bought from someone who said their child used it from elementary school through middle school orchestra.   Quite possible they'd had it sit for a few years after their daughter hung up her bow.  I think Woodland above is probably right, it's not been abused but I think my son may think the soft case is more protective than it is, and it probably gets bumped around.  I don't have a photo from when we first got it to know if it has changed much in the last five months. 

I'm really appreciating the input from everyone. 

[chiaroscuro_violins]

/

[Jeffrey Holmes]

3 hours ago, donbarzino said:

When a bridge warps the opposite way, as in the OP's instrument, I believe this is caused by putting the instrument away for a long while with the strings fully tuned. Since it is many times longer than the lower portion of the strings between the bridge and tailpiece,  the the playing portion of the strings stretches proportionally more and the bridge, being anchored to the strings, tilts backward. It would be interesting to know how, if at all, this instrument was used leading up to this situation.

Besides other things, the player relying too much on fine tuners on the tailpiece (not using the pegs often enough; I notice chiaroscuro beat me to this while I was writing) and string grooves that have worn too deeply (or were cut too deeply originally) are often a culprit.

I honestly don't have a problem with attempting to straighten most any warped bridge (for clients and the occasional neighbor's kid), especially if the cause for it deforming can be mitigated. Results can still vary in terms of re-warping (many student bridges are pretty terrible wood and some bridges do seem to have a "memory" of their past misbehavior, so I can't say I've never had a problem), but certainly in most cases the life of the bridge can be significantly extended.

I do tend (not always) to steam the bridge straight.  If they were cut with a small relief on the top of the backside I shim them appropriately and leave them clamped to a piece of granite so they can't deform while they dry (slowly and completely). 

[baroquecello]

I'm a cello teacher, not a maker. I have straightened bridges like these by floating them on water, with the (originally) flat side on the water surface, and just leaving them for a night or so, then clamping them flat on a glass plate. However, as others have said, more often than not, the cause of the problem lies in how the bridge was fit and this needs to be rectified, otherwise all of it is a waste of time. Mostly, the legs don't fit well, and/or the angle of the bridge to the top is wrong. Sunken in strings and badly lubricated string grooves make the situation worse. This particular bridge looks rather crudely made. I can see on this blurry pic that the feet don't fit properly, and the bridge was left very thick, particularly in the upper half. While straightening the bridge can be done by a handy person like myself, improving the fit and angle needs someone with experience, skill and knowledge, and therefore the best thing to do is to leave it to a lutier. In the case of this bridge, because it is so clunky and likely doesn't sound very good even when straightened, I'd seriously consider just ditching it and get a proper one made. Even student cellos sound and work much better with a good quality bridge. As a cello teacher I can say that I prefer a cheaper instrument with a good setup to something more valueable with a crappy setup. 400 Euros on a new bridge and fitting sound post and a set of proper strings (what is on there doesn't spring much hope in me) is, depending on the state of the rest of the cello, not ridiculous at all, even for cheap student instruments, if the resulting instrument is one which plays well and which will bring fun and ease to practising the cello. 

[reg]

I appreciate what MD has written and will myself take that lesson

...but in this case the OP would be better getting a new bridge setup correctly and new strings - rejuvenate the Cello!

[Andreas Preuss]

Replace. All re-bending methods I ve tried didnt hold long.

[nathan slobodkin]

This thread begs the question which I have asked before about what causes bridge warping in the first case. I have seen some bridges from excellent shops which are still straight after 50 years and some which have warped in a few months. I have definitely noticed that instruments kept in my show room seldom have warped bridges but often the bridge warps fairly quickly when they are in the hands of their new owners. I generally use Aubert bridge blanks and don't use any until they have been dried in my shop for a minimum of five years. Some of my deluxe bridges are 25 years old before use. I carefully select all the blanks looking for the closest grain hardest wood I can find and cut them as I was taught at Francais'. None the less I do not see the same warp resistance as  bridges from the Hill and Wurlitzer shops before 1980. Were they sealing or hardening their bridges in some way? I have been told that smearing a little shellac on the inside of cello bridge legs might help but can't say that I have seen much difference also have tried toasting the bridges until they darken slightly and have tried what some bowmakers do which is to heat and reheat the wood letting it cool partially but not completely between heatings which is reputed to "harden" the wood and set the camber. I would be happy if my bridges could be allowed to tilt 10 -15 degrees and still not bend which I have seen in some of the old bridges I mentioned but most of them just don't seem to be up to it.

[donbarzino]

I think "warping' is not the correct term. What we are talking about is bridge bending.

Warping hints at some defect in the bridge wood. I believe most of the bending we are discussing

has been caused by the string not being able to slide freely over the bridge but rather sinking into

and gripping the bridge and then pulling the bridge top out of alignment as the strings are tuned.

Perhaps us luthiers should be working on hardening the string notches on our bridges and teaching

our customers to check their bridge alignment as part of tuning. I'll bet the reason many old bridges

never warped is because their players were more diligent in keeping them upright.

[nathan slobodkin]

23 hours ago, donbarzino said:

I think "warping' is not the correct term. What we are talking about is bridge bending.

Warping hints at some defect in the bridge wood. I believe most of the bending we are discussing

has been caused by the string not being able to slide freely over the bridge but rather sinking into

and gripping the bridge and then pulling the bridge top out of alignment as the strings are tuned.

Perhaps us luthiers should be working on hardening the string notches on our bridges and teaching

our customers to check their bridge alignment as part of tuning. I'll bet the reason many old bridges

never warped is because their players were more diligent in keeping them upright.

For sure keeping the bridge in correct alignment solves most of the problem but despite my instructions to clients most don't pay enough attention. I have however seen bridges that have been left at a fairly steep angle for years without bending. These are the ones I would like to emulate but as I said most of my bridges don't seem up to that kind of treatment.

[David Burgess]

1 hour ago, nathan slobodkin said:

For sure keeping the bridge in correct alignment solves most of the problem but despite my instructions to clients most don't pay enough attention.

Have you tried beating them?

[Jeffrey Holmes]

43 minutes ago, David Burgess said:

Have you tried beating them?

Doesn't work and the bail outlay is prohibitive.

 

[Brad Dorsey]

6 hours ago, nathan slobodkin said:

…despite my instructions to clients most don't pay enough attention…

Maybe some of them would pay more attention if you made them bridge angle gauges.  These could be easily made from thin plywood to show the proper angle between the top and one side of the bridge.

[nathan slobodkin]

1 hour ago, Brad Dorsey said:

Maybe some of them would pay more attention if you made them bridge angle gauges.  These could be easily made from thin plywood to show the proper angle between the top and one side of the bridge.

This still doesn't answer the question of how so many of the really old bridges remain straight. It may just be that there were some bridges which were superior to others and those are the ones which remain on instruments today but how they were superior and whether that is due to the wood, the cut, or some kind of treatment would be very nice to know.

I see that some one has just started a thread about Greiner instruments. I saw one a while back which had an extremely thin bridge which the owner said was original to the instrument and I was surprised that it was still reasonably straight. I estimated the thickness of the bridge at less than 4 mm. and suspect something unusual such as permeating the bridge with glue was done to stiffen it.  

[donbarzino]

Thinking about those great old bridges that never warped.

Even if a bridge is kept perfectly aligned relative to the body by the player, another factor that could

bend or warp  the bridge  is its alignment with the string forces  transferred through it.

To maintain stasis it seems the bridge should perfectly bisect the string break angle over it.

This could be adjusted at the nut via the neck projection angle and with saddle height at the bottom.

I understand that standard practice is pretty close to correct but does anyone measure and adjust the

nut /neck position and saddle height to perfect the bisection?

It appears as though the nut, being farther away from the bridge would be set lower than the saddle to achieve the

same break angle at the bridge.

 

 

[nathan slobodkin]

I agree that it is logical to assume that bisecting the string angle would optimize bridge longevity although since the bridge is usually not symetrically shaped there may be more to it.  I also wonder if direct downward pressure perpendicular to the line of the ribs is necessary to optimize bridge function tonally. I suspect some one with a better grasp of engineering might be able to shed light on those questions. (Hi , Don ).

[Jeff White]

Like Brad D., I make new bridges with the  back perpendicular to the rib line with the belly. I also so a slight back cut (top of backside of the bridge, 1/2mm on cello). I would like to hear how others angle their new bridge work.  I've never really seen a bending problem that wasn't caused by player neglect.  I think this is the whole deal, not in any treatment of the bridges.  Daily, I"m correcting players on keeping their bridges straight.  I also have had great luck in straightening bridges the same way that MIcheal does it, with educating the client, and sometimes refitting of the feet.  

[David Burgess]

On 1/29/2022 at 9:56 PM, donbarzino said:

Thinking about those great old bridges that never warped.

Even if a bridge is kept perfectly aligned relative to the body by the player, another factor that could

bend or warp  the bridge  is its alignment with the string forces  transferred through it.

To maintain stasis it seems the bridge should perfectly bisect the string break angle over it.

Not necessary or even advantageous, since the interface between the strings and the bridge is not a "frictionless" rolling-element bearing.

However, I do like to cut a bridge to put forces through the center, to minimize distortion. If the client doesn't maintain the bridge at the intended angle, all can be lost. That's why some here furnish a client with something we sometimes call "an idiot stick", so that even a violinist with no engineering background or acumen can sorta get it right. 

[Jeffrey Holmes]

48 minutes ago, David Burgess said:

Not necessary or even advantageous, since the interface between the strings and the bridge is not a "frictionless" rolling-element bearing.

However, I do like to cut a bridge to put forces through the center, to minimize distortion. If the client doesn't maintain the bridge at the intended angle, all can be lost. That's why some here furnish a client with something we sometimes call "an idiot stick", so that even a violinist with no engineering background or acumen can sorta get it right. 

I have one client that calls it the "dip stick", and another that calls it the "stupid stick", but whatever one calls it, they have proven themselves handy.

[donbarzino]

I assume these bridge positioning sticks fit between the bridge and the end of the fingerboard?

What about keeping that stick in place during tuning so the bridge top stays in place?