Official Luthiers Forum!

Why can't a bridge be laminated, top to bottom, to reduce the possibility of cracking
along the line of bridge pin holes?

Will that affect the transmission of sound to the topas long as the
overall mass of the thing is equal to the traditional?

Jim McCarthy

Never tried that, but here is my take ...

The majority of bridges i have seen with cracks down the pin holes are for one main reason .. the holes follow a grain line. Since I make my bridges with the pin holes parallel to the saddle slot, thats usually not an issue. I also like to have the grain lines opposite to that of the pin holes line as well.

Not so sure that a "plywood" bridge would transmit as well either, as you state .. but then again, I have no intension of ever trying - I simply dont see the need.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Thanks for your reply, Tony.

I'm confused. You say that you run your holes parallel to the slot so as to avoid following the grain lines, I think.

But does the grain in your bridges runs more or less from front to back or parallel to the grain of the top?

If so, I've never seen that before.

Jim

Grain of the bridge should run perpendicular to the grain of the top. And the material should be riff sawn by a bit to aid in its long grain strength. I have never seen a bridge with the grain running parallel to the tops grain.

The grain runs the length of the bridge .... if its perfectly straight, then I am OK as my pin holes are at an angle to the grain, as they parallel the saddle slot, which is angled. If the grain runs at a bit of an angle, I make/orient the bridge such that the grain angle opposes the pin hole angle .. even better.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Think bridge cracks can be started or helped by folks forceing pins especially in times of rising RH. Having the pin holes follow parallel to the bridge slot is a good way to go as Tony has pointed out,it also gives down pressure angles that are somewhat equal to each other.And as a certain lady would say "thats a good thing".

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A person who has never made a mistake has never made anything!!!

There appears to be no real reason why you can't make a "plywood" bridge. I know of at least one very prominent maker that does this - his guitars are very well respected and command exceptionally high prices. Having heard his guitars side by side with other peoples first hand on a couple of occasions, I can attest to the fact that the "plywood" bridge has no discernable detrimental effect on the sound.

Regards,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Thank you, Dave. You have a nice website and I loved your rosettes.

Jim

Can you, sure folks can do a lot of things. Question is why. Just because things can be done, doesn't mean they should be, this is just one of them

OK. But why? The reason I've asked the question is because I'm not crazy about the aesthetics of a tradional bridge so I've been working on an alternate design that would be alot easier to make if I could laminate it instead of carve it out of something thicker.

What I take your response to mean is, 'stop asking questions and do it the traditional way'.

Or maybe I've misunderstood you. I'm sorry if I have.

Jim

Design of guitars and anything for that matter tends to be selective to the best design for the task. Few bridges do crack. Making a laminated bridge is something you can do , but if it was something that was beneficial it would have been carried on my more builders.
The best advice is I can give is that if you don't find the information you like , build it and see what you get and if it gives a result that pleases you continue. A guitar is a synergy of it parts. From all your questions , I can see you are trying to educate yourself. It is hard to teach yourself when you are both the student and teacher.
Find a few books and start a serious study. You will soon find that often there is different opinions among some experts. There is more than one way to build a guitar so you will have to learn what methods work best for the different designs. good luck and have fun

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Jim,
The bridge is glued to the top which is in turned glued to a bridge plate. In other words, you already have "plywood". A quality glue joint should not be an issue in sound transmission. I don't think it will be beneficial but I see no reason why it could hurt. The reason more builder's don't do this is because it is just an extra step with no real practical gain. Also, on most non-ebony bridges, a glue-line would look unattractive. If a laminate process makes the bridge easier to build, then I would encourage you to use two-piece construction.

Kind Regards,
Simon

There's a very simple reason "why" Stan. It's because the luthier in question makes a bolt-on bridge and needs to construct it with threaded inserts inside. However, I have been asked to keep the exact details of his design quiet, so I will respect his wishes and shut up about it. I tried a bolt-on bridge on the last guitar I built (using a derivative of my friend's method) and I must say that I was extremely happy with the result.

I'm with Jim on the general question as to "Why?" though. It does sound like you're trying to stifle experimentation and shove the traditional method down his throat a bit.

I, for one, love to challenge the status quo, in all walks of life, from my work (where it's my job to find new/better/cheaper techniques and ideas in the field of data communications) to my hobbies (lutherie, marquetry, fine furniture, music composition and recording, etc.). I have found that the most noise raised against new techniques/methods/tools comes from those who are threatened by them financially (where the new "thing" makes thier old methods uneconomical and threatens their livelihood, and/or they don't have the capital to invest in it). There usually is no physcial, mechanical, structural, or even artistic reason why the new "thing" shouldn't work, yet the noise-makers generally use these avenues as excuses to denegrate it. It does appear to me that the "old guard", in all walks of life, are not nearly as flexible and open to new ideas as they think they are!

Wo be the day that I become one of the "old guard"!!

Regards,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Thank you Simon. That's helpful.

Jim

I've got a laminated bridge on one guitar. I wanted the head plate, fretboard and bridge to match. The piece I had was just over a 1/4", so I added a piece to the bottom. I made it thin enough that the added piece is below any shaping so there is no glue line visible. No it isn't Ebony either, it's Jatoba. The guitar sounds fabulous according to everyone who has played it. Would it sound better with a 1 piece bridge? I doubt it. I'm not pulling this one off to find out.
I think that a laminated bridge using some contrasting woods could be visually pleasing. Just look at Mr. Klepper's dovetail madness guitar. Some shapes would lend themselves to this better than others. Perhaps one of the really good builders could adjust the tone of the insturment by adding some lower damping material to a piece of Ebony and still have that cool jet black look to the bridge.