Sign in to follow this  
richardz

Straightening a warped violin bridge?

Recommended Posts

richardz   

I have a violin with a bridge that is warping. The top is tilting backwards. I'm guessing a new set up is in order, but this bridge (from a previous owner) was made in one of the best NYC shops. Is it possible to straighten this bridge? How?

Thank you for any suggestions/input.

Share this post


Link to post
Share on other sites

Yes. Steam it, then clamp to a flat surface and let dry (completely).

It may not be as reliable as it once was (once a bridge warps, it may do so again), but if it was made correctly, you can get significant life out of it yet.

Share this post


Link to post
Share on other sites

Richardz,

Jeffrey may cringe, but I'll tell you what worked for me with a

warping, wafer-thin bridge:

Boil it (better than steaming) for a few minutes, then clamp it

straight and let it fully dry.

next, fill the bottom of a large paper cup with Minwax Wood

Hardener.  Soak the bridge in this for 5-10 minutes.

Wipe it off and let dry.  Good idea to clamp it again while it

dries.

When dry, give it a very light sanding to remove the residue.

THis not only saved a badly flexing bridge, it actually improved

the tone of that particular violin.

YMMV.

A lot.

---------

FWIW,  I was recently at the shop of one of NYC's best

repairmen.  I had brought that particular violin for a neck

lift and full set-up, so I mentioned in to him,  passing, my

little experiment.  He just smiled and pointed to the shelf:

 Yup, several cans of Minwax wood hardener.

When I picked up my violin the next week, sure enough the new (also

very thin) bridge was soaked in the stuff.  Sounds amazing.

 

Share this post


Link to post
Share on other sites
richardz   

Thank you Jeffrey. Because of who made it, I have always thought of this bridge as a sculpture and memento as well as being a beautiful bridge. I'm very happy to hear it is salvageable.

Allan, thank you also for some more excellent advice and additional details. This gives me a lot to play with.

Would either of you venture an estimate of drying-out time after steaming/boiling? I've never done this type of thing before. My guess would be overnight, say 8 hours? Would that be correct?

Share this post


Link to post
Share on other sites
Guest   
Guest

Having never tried the Minwax method, a couple of questions:

Does it do anything to the feet to encourage any kind of slippage ?

Or given a light sanding, is this a non-issue ?

A helpful tip though!

E.

Share this post


Link to post
Share on other sites
Bacon   

As we do a large amount of school repair on a limited budget one way we have resolved this problem is with a microwave. We set the concave section of the bridge face down on a damp rag and microwave from 3o seconds to one minute on high. It differs with different machines. Too much microwave too long will burn the bridge from the inside-out. This usually does the trick for violin and cello bridges , bass bridges take a few times.

Share this post


Link to post
Share on other sites
GMM22   

For those who pay attention to such things, it is worth noting that Minwax Wood Hardener is quite hazardous. The MSDS health rating is 3, which stands for "Serious". Use with caution. Personally, if I needed a stiffer bridge that badly, I would make one of ebony.

Share this post


Link to post
Share on other sites
Collin   

If we're going to go into bridge hardening, I might as well
mention my method - borax. It may not be considered traditional,
although it was allegedly used in violins as an insect
repellent in 18th century Cremona.



Anyway, here's how I do it:



1. Boil the wood in plain water until it sinks

2. Add borax until it is saturated (or almost)

3. Let it simmer for 20 minutes or so. don't boil it for too long,
though. the borax will then become saturated in the wood (if you
are concerned about this, use a more conservative mixture)



The borax works by cross-linking the polymers in the wood, so there
is a happy medium between having too much and too little borax.



I don't want to sidetrack the discussion, but this has worked very
well for me.

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
richardz

Thank you Jeffrey. Because of who made it, I have always thought of this bridge as a sculpture and memento as well as being a beautiful bridge. I'm very happy to hear it is salvageable.

Allan, thank you also for some more excellent advice and additional details. This gives me a lot to play with.

Would either of you venture an estimate of drying-out time after steaming/boiling? I've never done this type of thing before. My guess would be overnight, say 8 hours? Would that be correct?


My advice is simply; if you like the bridge, try steaming or boiling (as long as the water is already boiling when you put the bridge in. it's about the same thing.

If the bridge is so weak you need to add stuff to make it stiff, maybe it's time to have another bridge installed.

I let bridges dry for about 8 to 10 hours after steaming.

Good luck!

Share this post


Link to post
Share on other sites

A quickie way of straightening is to moisten the concave side and warm the other side, like over a hot plate or bending iron. The moisture differential will warp the bridge in the other direction, and the heat will let it bend more easily and help it take a set.

quote:


Originally posted by:
Collin

If we're going to go into bridge hardening, I might as well

mention my method - borax. It may not be considered traditional,

although it was allegedly used in violins as an insect

repellent in 18th century Cremona.

Anyway, here's how I do it:

1. Boil the wood in plain water until it sinks

2. Add borax until it is saturated (or almost)

3. Let it simmer for 20 minutes or so. don't boil it for too long,

though. the borax will then become saturated in the wood (if you

are concerned about this, use a more conservative mixture)

The borax works by cross-linking the polymers in the wood, so there

is a happy medium between having too much and too little borax.

I don't want to sidetrack the discussion, but this has worked very

well for me.</p>

Could you share your evidence that

(a) borax hardens the wood

(:) that it cross-links the polymenrs

© that hardening a bridge is advantageous

Thanks.

Share this post


Link to post
Share on other sites
Collin   

quote:


Originally posted by:
David Burgess
[/iCould you share

your evidence that

(a) borax hardens the wood

(
:)
that it cross-links the polymenrs

© that hardening a bridge is advantageous

Thanks.

Sure.

(a) the drop tone goes way up, and it becomes very apparent when

carving

(:) In one of Nagyvary's interviews, he mentioned using borax in

varnishes, saying that "[borax] is commonly used as an

insecticide, but in this mixture it acts as a cross-linker, weaving

the chains of sugar molecules into a sort of web."

© For an overly warm/dark/muffled instrument, one would generaly

want a very light bridge so that very little of the upper spectrum

(as in an FFT) is lost - with a hardened bridge, one can go

thinner without structural problems. Even with an instrument that

does not require the bridge to be treated thus, one will get a much

clearer, more open sound - whether the bridge is left thick or thin

(within reason).

If the powers that be want me to move this to a new thread, let me

know.

Share this post


Link to post
Share on other sites

I sometimes strengthen a warped bridge, after I've straightened it, by soaking it in a glue solution.(usually yellow glue & water) Or by applying extra thin CA Glue to the end grain, especially on cello bridges. But Minwax hardener is a good choice because it does not add much mass. I don't know if a stiffer bridge in necessarily better, but I do know that a warped bridge is bad, so if the straightened, hardened bridge doesn't work out, not much is lost.

~OK

Share this post


Link to post
Share on other sites
Collin   

Minwax hardener (or glue) works by putting the solution in between

the fibers, whereas borax strengthens the fibers themselves. I

could measure the mass difference sometime - but for the time being

I don't have time for that. I would assume that borax adds less

mass then Minwax or glue. I was taught that the harder the blank

the better(within reason, of course) - measured primarily by drop

tone.

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
David Burgess

A quickie way of straightening is to moisten the concave side and warm the other side, like over a hot plate or bending iron. The moisture differential will warp the bridge in the other direction, and the heat will let it bend more easily and help it take a set.


Yup... Works pretty well. I did find that the brdge tends to stay straight better (for me) when I really do the steam/dry thing though. Don't know why. Maybe I wasn't waiting long enough when wetting one side and heating the other (still damp)?? Don't know.

Anyway, concerning Borax, hardners, and all... I think I've had the best luck with untreated bridges... although I have some treated ones I like as well. I do heat the outside (temper) them... and like the results in terms of wood color as much as tone (in other words, if there was no noticable tonal change I'd do it anyway). Not sure how much of the tonal change remains anyway... but if some does, I'm happy.

If there was a treatment that actually "improves" a bridge tonally and structurally... I'd imagine it's something to consider using when cutting a new one, right? Doesn't make sense to me to treat a warped bridge that's simply too weak or badly cut (or bother straightening it for that matter). Seems like all you'd end up with is a stronger, but just as poor, bridge? Why not cut a new one?

Share this post


Link to post
Share on other sites
Collin   

quote:


Originally posted by:
Jeffrey Holmes
[/iIf there was a

treatment that actually "improves" a bridge tonally and

structurally... I'd imagine it's something to consider using when

cutting a new one, right? Doesn't make sense to me to treat a

warped bridge that's simply too weak or badly cut (or bother

straightening it for that matter). Seems like all you'd end up with

is a stronger, but just as poor, bridge? Why not cut a new one?

I agree completely. Personally, ever since I have discovered the

effects of borax, there has not been one bridge that I have cut

that I end up treating immediately thereafter. The tone quality

always improves. Always. (I try them out fully strung before and

after treatment). FWIW, I tend to use untreated bridges, as well,

and then treat them with borax. The treatment that is usually used

on treated blanks interferes with the borax treatment.

Share this post


Link to post
Share on other sites
richardz   

Thank you all for the input....Now results:

I ended up steaming the bridge for about 10 minutes in a vegetable steamer. I was amazed to see it straightened out after about 3 minutes. I clamped and dried it for about 10 hours overnight and put it back on the violin. It sounded better than the warped bridge obviously. I checked it later in the day and noticed a very minute warping happening again so I figured there was nothing to lose by doing the Minwax hardener treatment. I treated it, clamped and dried it and reinstalled it yesterday. I played it for a couple of hours after work today and it has maintained its shape with no further warping so i think it works in a structural sense. It's possible it is now a little louder. In that way the steaming and hardening is a great success.

The next part is interesting but a little bit anticlimactic. I think the violin might be louder now and have more punch. The anticlimactic part is the violin had tonal issues before and that hasn't cleared up. It may in fact be more noticeable (which I don't necessarily think is a bad thing). It might be projecting more vibration through the violin accentuating whatever problems it had before. Basically it has a very bright loud clear e string but the ADG strings are loud and woofy(?) without a clear core sound to them so they don't cut or project much, but they do seem louder. As Jeffrey said, if the bridge has a weakness you probably need a new one anyway. It is probably true in this case. It probably needs a whole new set-up. I'm experimenting with different string combinations with some interesting but not excellent results. I think it probably needs some expert attention in the end.

An interesting side note: as I was examining the bridge before treament I noticed a gloss on the lower portion which gave way to bare wood above the waist height, leading me to think the bridge was perhaps initially treated by the excellent NYC shop and then possibly the top half carved down by someone else (for whatever purpose) and this led to the weakness in the top portion of the bridge and possibly not the fault of the original maker.

This was an enjoyable interesting process which also brought up for me, the concept of string tension and how it effects the violin. If the bridge is warped you are lowering the bridge height/string tension/distance of the strings above the fingerboard/and distorting the pathways the sound/energy passes through the bridge. When you straighten the bridge you are effecting all these variables....very interesting.

Thank you all again for all the input.

Share this post


Link to post
Share on other sites

quote:


Originally posted by:
Jeffrey Holmes

Yup... Works pretty well. I did find that the brdge tends to stay straight better (for me) when I really do the steam/dry thing though. Don't know why. Maybe I wasn't waiting long enough when wetting one side and heating the other (still damp)?? Don't know.


Not saying it works as well as steaming. You need to over-bend a bit......it's a judgment call and doesn't always come out right the first time.

It's just one more thing to have in ones arsenal in case the customer is picking up the instrument in a half hour.

Share this post


Link to post
Share on other sites
GMM22   

It is helpful to overbend slightly to allow for some inevitable recovery. I use a three point clamping system with shims (one at the waist and the other two on the other side at the peripheries). I have found that much better reliability is attained if the bridge stays in the clamp for at least a few days. A solid piece of wood that has been wetted will not give up all excessive moisture overnight.

Share this post


Link to post
Share on other sites

I appreciate the tips on bridge straightening. The hardening idea is interesting. Early on, I tried using linseed oil on the bridge -- read it somewhere -- but didn't really like the results. Seemed to muddle the sound a bit, but I didn't try it on too many instruments. I guess that's part of the science that's hard for me -- how many times do you try something before you can claim you know what that certain method does to a violin in general?

And on the panic repair -- I ran across this story some time ago. You could replace 'cobbler' with 'luthier' I suppose.

One weekend, a couple are cleaning house, when they run across a pick-up ticket from a shoe-repair store.

The husband looks at the ticket, dated 10 years prior, and says: "I forgot all about these shoes. You know, I pass by that shop on the way from work. I'll stop in on Monday and maybe the old guy will get a kick out of it."

So on Monday, the fellow walks into the shoe store, and sure enough, the old cobbler is still there, a bit older. The fellow hands the cobbler the ticket. The cobbler squints his eyes at it, then, without a word, walks into the back room.

A few minutes later, he comes back and says: "They'll be ready Thursday."

Share this post


Link to post
Share on other sites

Here is an earlier discussion on heat treating (microwaving) bridges which I found useful when I reread it--I had contributed to it but had forgotten most of what was covered:

">http://www.maestronet.com/foru...RUMVIEWTMP=Linear

Perhaps a shop technique for the customer that returns in 30 minutes is to (1) flatten the bridge with water and the iron, (2) followed by a short soak in the Minwax Hardener, (3) followed by a short bake in the microwave to set the Minwax hardener. Anyone tried this?

Mike D

Edit--I just tried this (I used Minwax penetrating oil finish rather than hardening stuff) and the microwaving caused the flattened bridge to rewarp. Maybe it would have to be clamped flat during the microwaving or maybe this technique will not work at all to speed up the process.

Share this post


Link to post
Share on other sites
COB3   

Do remember not to use metal clamps (!)

Nasty things happen to microwave ovens if you forget that--or so I am told.

Share this post


Link to post
Share on other sites
GMM22   

It is worth noting that wood strength is comprimised with excessive heat. If the exposure time and temperature is low, the negative impact is minimal, but I think microwaving is a very uncontrollable process. It seems quite possible to overheat a bridge (and unevenly too) thus compromising wood strength and stability.

While slower, an oven would offer much better temperature control. Personally, I just apply a soaked Qtip to the waist area and allow sufficient water to wick into the endgrain. I then clamp incrementally three or four times in small steps over a few hours and let dry for a few days. Tedious? Maybe, but it nets flawless results.

Share this post


Link to post
Share on other sites
quote:


Originally posted by: Mike_Danielson Perhaps a

shop technique for the customer that returns in 30 minutes is to

(1) flatten the bridge with water and the iron, (2) followed by a

short soak in the Minwax Hardener, (3) followed by a short bake in

the microwave to set the Minwax hardener. Anyone tried this?

Been there, done that, NEVER AGAIN.

the Minwax heats up to the point that it burns the Maple.

Perhaps a gentle warming in a convection oven would

work, but definitely NOT a microwave.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.