Bridge treatment - what is the purpose?

[David Burgess]

re: subject bridge

2 days down and still rings at A natural

 

This is a drop test which is a little tricky.. the bridge has a taper which will render more that one ring (as will a tapered bow) but is easy to do and is in keeping with kyproset's posting of 30 May

 

Obviously my interest is up.... so at the end of two weeks I will fit it on a violin, along with a companion bridge (not baked), which I am using as a control

 

The "drop test" excites resonances which probably aren't very significant to the sound of the violin.

 

You might do better by setting up to measure "rocking" frequency or stiffness, alterations of which are quite well validated for producing significant sound and playability changes.

[jim mcavoy]

Stamm bridges

these are most likely made from wood subjected to long term soaking (submerged) in water and then slowly and carefully dried 

for what it is worth (wood treatment) see

http://www.milostamm.com/e_tipps.htmhttp://www.milostamm.com/e_tipps.htm (go to makers secrets)

 

Jim

 

 PS this is at least a 3 or 4 year project (and you have to catch the right bugs)

[jim mcavoy]

The "drop test" excites resonances which probably aren't very significant to the sound of the violin.

 

 

David,

I quite agree

 

I am just using it to see if there is a change over time  I don't think the actual ring is all that important (other than to compare something to something)

 

the ring that I hear is in the third octave above middle C ....much higher that most people play and that ring will change in the fitting process

Jim

Edited June 11, 2015 by seammc

[David Burgess]

Somewhat regrettably, I think that a darkened bridge is just a bit of presentation that counts for much and gives the instrument a look of being attended to in every possible way. It goes along with polishing the shanks of the pegs, and those other tiny elements of presentation. It contrasts against the rushed bridge, which normally has no colour, and as others have said earlier - can - look cheap. 

 

I wish I had a clever and less mysterious answer!

Hah, being somewhat the colonial rebellious type, I neither color nor stamp my bridges.

 

I'll confess to polishing my shank(s) though.

[martin swan]

The "drop test" excites resonances which probably aren't very significant to the sound of the violin.

 

You might do better by setting up to measure "rocking" frequency or stiffness, alterations of which are quite well validated for producing significant sound and playability changes.

I've been doing the drop test for fun (who can say whether a high or a low note will suit a particular violin), but I notice that the note tends to be different depending on which side of the bridge hits first.

Should we take an average?

I prefer to think that the stiffness of the finished bridge is the main thing to control, and that there are many ways of arriving at a similar result. Thickness, carving away wood, ankle width etc

[jim mcavoy]

I've been doing the drop test for fun (who can say whether a high or a low note will suit a particular violin), but I notice that the note tends to be different depending on which side of the bridge hits first.

Should we take an average?

I prefer to think that the stiffness of the finished bridge is the main thing to control, and that there are many ways of arriving at a similar result. Thickness, carving away wood, ankle width etc

 

Martin,

Re: A variation on the drop test

If you tap the bridge face at the crotch (close to the edge and centered between the legs) with a small hammer ( 10- 20 grams) you should hear the upper ring tone, it starts low and goes high  I hold the bridge by one foot

 

Jim

Edited June 5, 2015 by seammc

[mrbadger]

On the ammonia treatment issue. Yes, ammonia has been used to darken wood (especially popular for white oak in Stickley and Craftsman furniture). It's a fuming process.

 

However, ammonia is also used for industrial wood bending. Fuming wood with ammonia soften the lignin and allows wood bending without the heat and/or moisture. Since this is anhydrous ammonia, however, it's not a small shop kind of technology.

 

Since it softens the lignin, however, it likely has a de-damping effect on the wood, relieving and inner stresses left over from milling and drying. The soaking and careful drying likely does the much the same. Although the ammonia fuming would be kind of like taking a sledge hammer to a finish nail.

 

Careful drying an a bit of age does the work much more gracefully. 

[Ben Hebbert]

Hah, being somewhat the colonial rebellious type, I neither color nor stamp my bridges.

 

I'll confess to polishing my shank(s) though.

 

Being somewhat the colonial rebellions type, I was expecting you'd be dunking them in tea to get a stain (or maybe just in Boston harbour). 

 

Polishing your shanks is one thing, but giving your endpin the same attention is quite another. 

[jack london]

I just tried the drop test on my bridge and broke the violin right over the sound post.   Next time i will take out the post before trying this.    Oh, and the sound was not pretty.   

[Craig Tucker]

I just tried the drop test on my bridge and broke the violin right over the sound post.   Next time i will take out the post before trying this.    Oh, and the sound was not pretty.   

 

Yeah, but...

 

 You apparently, simply weren't listening for the right sound...

 - did the violin "snap", "crackle", or "pop" when it cracked in half?

[jack london]

I just tried it on my second fiddle.   It is definitly a pop, but I can't tell the tone.    Not wanting to change too many variables, I left the post in and got the same crack in the top and another directly beneath it on the back.    Later today  I will try it again on my wife's violin, but this time I will take out the post.   

[Craig Tucker]

I just tried it on my second fiddle.   It is definitly a pop, but I can't tell the tone.    Not wanting to change too many variables, I left the post in and got the same crack in the top and another directly beneath it on the back.    Later today  I will try it again on my wife's violin, but this time I will take out the post.   

 

Well, they say that;

"practice makes perfect"

 

 - so, good luck with your wife's violin...

here's hoping that her dang bridge will be a bit more compliant! 

[jim mcavoy]

Re: oven bake @ 190F ~ 1 hour

I have come to the conclusion the what has happened to my test piece is a very low grade of case hardening(runing deeper than expected). If there is any advantage to be taken remains to be seen, I expect any change to be subtle and subjective, as with all things violin oriented

 

the current design of  the sandard bridge is truely a marvel  The are three resonators (pendulums) found on the bridge, a low fequency at the heart and two higher at the kidneys (generally, not to be messed with unless changing the resonances of the bridge, and then in the direction of the resonance change....good trick)

 

Jim

Edited June 8, 2015 by seammc

[jim mcavoy]

I have fitted a baked bridge and it sounds Great!    I feel like kyproset and his Stamm experience

the bridge has been finished 2.5 mm at the top, mid way down 3.7 and 4mm at the feet which is thicker than my normal bridges

 

The kidneys have been opened up  2mm+/- (O E Rodgers style) to reduce the bridge resonances and there is a modest arch at the crotch .... no other Fancy Dan scraping was done.....A first for me

 

The sound bold, and is mid way between coarse and sweet and not at all wimpy (big voice) and is neither tuby nor edgey

 

The curious thing is that all of my bows work well on the violin (my 3rd violin)

 

The strings are set a little high (bridge and nut) as, mostly, I don't descend to the finger board when  playing

 

I did have to slide the little tube onto the bridge at the 4th string location  because playing the G on the 3rd string caused the 4th string to resonate ...all fixed.

 

Is this typical for a baked bridge... I have no idea, as this is only the first one and eventually will do more to find out

 

This is, at long last, my answer to the topic question (and to get a better bridge ~ out of a large number of choices)

 

cheers

Jim

Edited June 8, 2015 by seammc

[jim mcavoy]

Re: oven bake @ 190F ~ 1 hour

farther testing on a vso that was just a flyer  that is strad like as far as the mold goes (origin China)

 

From a trotting horse it looks like a build done with loving care

 

When I got it the pegs were a two taper fit and it was unplayable (( a stone mason would have done better) ...Fixed those and and fixed the finger board (it curled up like a banana) And it then it played, 'kind of'. ..bridge was a disaster~but it did hold the strings off the fingerboard ..then put it up for a couple of years     I like my above long pattern a lot better

 

Today, got it out and I tryed an unbaked bridge ...it sounded much better..... then baked the bridge

 

It was then a little louder and brighter and doesn't wimp out in the fifth position and this violin low G string also resonated (probably the bridge cut) when playind 3rd string G (a little G string muteing fixed that) ..all bows seem to work on it

 

conclusion is ~ works but won't knock your socks off ~ better baked then not baked Acually I tryed two bridges ,(O E rogers style) one was ok the other sounded a little edgey ????? ~ well they are 50 cent bridges

 

also

O E Rogers style =

http://www.oosterhofonline.net/pdf/Bridge_wood_removal_Rodgers.pdf

I made all 4 cuts, but used a top to bottom graduation of 2.5 to 4 mm (Above link fixed)

 

Jim

Edited June 10, 2015 by seammc

[jim mcavoy]

I pray that there is no transgression here ...this is taken from the Milo Stamm bridge site  No copywrites were indicated....

 

This is wordy and deals with water treatment (read the comment at the end) It deals with violn tops and backs ~ wood is wood and bridges are wood

 

(These is a letter taken from Mr. Stamenkovic and Mr.Folland correspondence. They have discussed the wood preparation issue.)

 

Dear Mr. Folland,

I would like to share a story about the experience of Mr. Gaspar Borchardt of Cremona: I discussed with him the problems of wood treatment a lot of times.

During the better part of fifteen years we have been acquainted, first mistake he made was his lack of patience which resulted in the wood he was working with being taken out of the water too early ( after about 6 months ), second mistake he made was using the same wood to make a violin a few months later. His third mistake was that the next batch of wood he attempted to treat was submerged with a too low a ratio of water to wood (too little water too much wood), 102 mistake he made was ....., 403 mistake he made was...

 

It took a few years for him to completely unintentionally go back to the first batch of wood he attempted to treat and unhappy with the results dismissed the value of the wood treatment. He made a violin which he did not consider important but when completed turned out to sound incredible, his lack of patience was compensated for by time, and the bacteria in the wood completed the process by themselves in the course of the few years they were left on their own.

I hope you understand that the treatment does consist of submerging the wood in water; active processes start at the point of wood being taken out of the water.

 

The important thing is to understand that after the wood is taken out of the water the real

treatment begins; and that the wood instead of being immediately dried should be kept moist as long as possible.

 

The story about Paolo Vetorri: ten years ago, he made the trip from Bologna in order to share his short story with me: “I was very young, at the beginning of my career, my grandfather talked me into submerging a great quantity of wood (Into which I had sunk my life savings) under water. I did so and after a while the wood turned very dark and practically unusable. I was very angry at my grandfather and did not speak to him for a long time believing that he ruined the beginning of my career. Only now, after 50 years do I realize my mistake; I had not submerged the wood properly so it was, after absorbing a great quantity of water, partly exposed to air. This caused it to darken and be unusable. Now I know that you and my grandfather are right"

.

What I am trying to say, is that making mistakes in this process is inevitable, but large mistakes can be avoided if: you allow app. 10 liters of water per one piece of violin wood; put it all into a container that does not have acidic reactivity ( plastic container ), under no circumstances into a metal one; this wood should be kept under water at all times with a glass or a plastic weight , stone and metal both cause acidic reactions, wait until the wood stays at the bottom by itself after the weight is removed and then leave it for another few months under water until the wood is completely permeated with water to its core.

 

Allow me to digress a little regarding your comment that it is necessary for the wood to be fresh in order to be treated. If we assume that average air humidity of our environment is 77 % we can then conclude that the wood stored in your workshop is NEVER dry, however much you hoped for it and that this wood, as any other organic matter, contains bacteria within. This bacteria may not be completely active and able to proliferate. But they are not, by any means dead. They can lay dormant for years until necessary conditions of humidity and temperature are met. Therefore it is absolutely possible to treat the wood which has been stored for extensive periods of time.

 

Let us go back to our previous theme. So; you have taken the wood out of the water; now the real process starts and also the possibility of making mistakes raises dramatically.

 

Example:

a. you have stored the wood in a place that dries it too fast, the bacteria get lazy again before they have disintegrated enough sugars within the wood;

 

b. you have stored the wood in a place too humid (a cellar for example ), on the surface a fine cobweb has formed, yeast has developed which enter the structure of wood, eat the basic protein structure of wood and your wood is now unusable;

 

c. you have done everything correctly, but have stored the wood on a shelf and are patiently waiting for months only to discover that yeast has formed again on the surface of the wood touching the shelf it was stored on. Oh no! You have forgotten to elevate the wood from the surface so that the air can circulate freely.

 

d. you have done this previous point correctly but have forgotten to leave the necessary distance of min. 3 centimeters between two pieces of wood, in this space excess humidity allowed the yeast to form and again you have a problem.

 

e. you have done the previous correctly as well, but have allowed the back of the wood to be too close to the wall and again yeast has attacked.

 

f. Very important question is if the wood has been stored on the shelf ( strip of wood separating it from the shelf ) with the bottom surface being the wider part of the wood or if you have laid it down on its side ?

 

My visit to Guiccardi 1999: he showed me 150 pieces of violin maple wood in his workshop of which he considered 147 to be inferior and only 3 usable for making a high quality violin; when split, only the 3 pieces had the same tone on the left and the right side when knocked on. He was desperate because all of the wood was of high quality to start with and he could not fathom why this was happening. “Only these three pieces can be used to make high quality violins the rest also have to be used for violins, and this leaves me with an existential and moral problem, because I cannot make a living from just three violins ".

I tried to explain to him that in wood stored in this manner (on top of each other), humidity in warm months moves upwards just as vapors do and that in the more humid parts of the wood, being permeated with more active bacteria, less sugar remains therefore making the difference in tone inevitable. Generally his problem contained in his less than careful storage of wood.

 

g. You have done everything right, but somewhere between 12.00 and 1.30 on a summer day sun enters your workshop and lingers on the wood for a while, your wood starts drying too rapidly and cracking, micro air pockets have formed within the wood, your hair has risen and at this point you responsibly decided to change your profession...

 

My advice: find 3 pieces of maple wood cut from the same tree and also 3 pieces of spruce wood also cut from the same tree, mark each of them with a date. First set a maple and a spruce store exactly as you have been doing so far in your workshop. Second set a maple and a spruce throw into the water as I previously elaborated.

 

THIRD SET A MAPLE AND A SPRUCE, AS THE OLD MASTERS PROBABLY DID, LEAVE SOMEWHERE IN YOUR YARD WHERE THEY ARE NOT EXPOSED TO TOO MUCH HUMIDITY, NOT EXACTLY ON THE GROUND, WHERE THEY ARE SOMETIMES TOUCHED BY THE SUN AND SOMETIMES RAINED ON.

 

The second set of wood you should take out of the water after approximately 18 months and follow my previous instructions perfectly, and please avoid any mistakes!

 

DO NOT BE CONCERNED IF THE WOOD FROM YOUR THIRD SET TURNED GRAY, IT IS ONLY ON THE SURFACE, INSIDE IT HAS BEAUTIFUL GOLDEN BROWN COLOR, THE CRACKS FORMED BY THE SUN ARE NOT DEEPER THAN 6 MILLIMETERS, And SO YOU CAN CUT THEM OFF WITHOUT A PROBLEM. SOMETIMES ROTATE THE WOOD, MOVE IT TO ANOTHER CORNER IN YOUR YARD... IN OTHER WORDS TREAT IT AS ANY WOODWORKER EVEN TODAY TREATS HIS WOOD; WITH EASE AND NO TREPIDATION.

 

Few years later make violins out of the three sets of wood, one after the other. Compare them.

 

My comment: If you allowed me I would advise you to skip the first two experiments altogether you are wasting your time!

 

Don't think it is easy for me while my wife (whose English is much better than mine) is translating this letter to you. I would just be very happy if I managed to save you 30 years of unnecessary and painful experiments.

 

Milo Stamenkovich

[uncle duke]

I wonder if violin wedge wood still converts co2 to oxygen after processing.

[jim mcavoy]

Re: water treatment

 

Yup, I have some  ($ ~ 50 cent) bridges in water (to see what happens) with no great expectation of sucess.

 

Jim

[jim mcavoy]

I wonder if violin wedge wood still converts co2 to oxygen after processing.

can't say....  but there is a lot of 'air' in a bridge .. my soak produced  air bubbles at the outset resulting in an air space in the jar

 

after 24 hrs I have 2 sinkers and 2 getting there

 

Jim

[DGV]

 

My advice: find 3 pieces of maple wood cut from the same tree and also 3 pieces of spruce wood also cut from the same tree, mark each of them with a date. First set a maple and a spruce store exactly as you have been doing so far in your workshop. Second set a maple and a spruce throw into the water as I previously elaborated.

 

THIRD SET A MAPLE AND A SPRUCE, AS THE OLD MASTERS PROBABLY DID, LEAVE SOMEWHERE IN YOUR YARD WHERE THEY ARE NOT EXPOSED TO TOO MUCH HUMIDITY, NOT EXACTLY ON THE GROUND, WHERE THEY ARE SOMETIMES TOUCHED BY THE SUN AND SOMETIMES RAINED ON.

 

The second set of wood you should take out of the water after approximately 18 months and follow my previous instructions perfectly, and please avoid any mistakes!

 

DO NOT BE CONCERNED IF THE WOOD FROM YOUR THIRD SET TURNED GRAY, IT IS ONLY ON THE SURFACE, INSIDE IT HAS BEAUTIFUL GOLDEN BROWN COLOR, THE CRACKS FORMED BY THE SUN ARE NOT DEEPER THAN 6 MILLIMETERS, And SO YOU CAN CUT THEM OFF WITHOUT A PROBLEM. SOMETIMES ROTATE THE WOOD, MOVE IT TO ANOTHER CORNER IN YOUR YARD... IN OTHER WORDS TREAT IT AS ANY WOODWORKER EVEN TODAY TREATS HIS WOOD; WITH EASE AND NO TREPIDATION.

 

Few years later make violins out of the three sets of wood, one after the other. Compare them.

 

My comment: If you allowed me I would advise you to skip the first two experiments altogether you are wasting your time!

 

The third option sounds to me that treating wood like dirt is the best approach.  How does one reconcile this with the practice of baking wood that some MNers have been doing?

[DGV]

Re: water treatment

 

Yup, I have some  ($ ~ 50 cent) bridges in water (to see what happens) with no great expectation of sucess.

 

Jim

 

Do you soak the bridges and then bake them?

[jim mcavoy]

Do you soak the bridges and then bake them?

Right now, I am treating them as two separate approaches

 

No ritual chants or auspicious omens. ~ Just want to see if there is anything to it

 

I do think that the time spent would be better served by introducing the bugs in the soak water (they work great at turning wine, skipping the wine stage, into vinegar) If you catch a slime in all of this,all is for nought (I don't want to mulch the bridge)

 

Jim

 

PS The bridge on the vso was treated, by the maker, with linseed oil . I don't live in the rain forest (or the high Andes) so I don't see much value there

Edited June 12, 2015 by seammc

[DGV]

I think I'll stick to baking for now.

[jim mcavoy]

I think I'll stick to baking for now.

Good luck ~ If you have any success, and are willing, please post them

 

Jim

[captainhook]

That Stamm letter does not mention bridge wood, only plate wood. Not sure why you would assume the same for bridge wood.