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Classical Bridge Material
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=22829		 Page 1 of 2
Author:  RaymundH [ Mon Jun 22, 2009 2:30 pm ]
Post subject:  Classical Bridge Material
Good Afternoon,

What, in your opinions, is the best tonewood material for a high end classical guitar bridges.

Thank you,

Ray
Author:  WaddyThomson [ Mon Jun 22, 2009 2:35 pm ]
Post subject:  Re: Classical Bridge Material
Most would say Brazilian Rosewood, without hesitation. I used it on my first, and it was very good. I used Cocobolo on my second, and it was good too. With Coco, though, you have to watch the weight. There are other good woods too, but some of the other rosewoods are the best. Some use Ebony, but others say it has too much damping for a classical. I don't know, but I figure I come out with a better chance of a good guitar if I stay away from anything with a question mark by it. Madegascar Rosewood also gets high marks for classical bridges.
Author:  Colin S [ Mon Jun 22, 2009 4:23 pm ]
Post subject:  Re: Classical Bridge Material
As Waddy said BRW is the wood of choice 99 times out of a hundred, I'm tempted to say that the other 1 would be Rio rosewood, but if I'm honest it would be Madagascan rosewood. EIR can be used, and some have used Padauk, but you did say high end giutar so yes that would be BRW. (Made two today, bridges that is not high end guitars))

Colin
Author:  Mike Collins [ Mon Jun 22, 2009 4:43 pm ]
Post subject:  Re: Classical Bridge Material
I love Braz.wood for bridges.
BUT there are less weight woods that will make a great bridge & maybe a better sounding guitar.
Walnut ,Indian R.W.,Maple,Imbuia,Myrtle,-weight is important.

The ability to resist string pull is only important if the bridge design is optimum in this area.

Mc
Author:  patmguitars [ Mon Jun 22, 2009 7:28 pm ]
Post subject:  Re: Classical Bridge Material
Hey Guys

I beg to differ a bit, but of the many high end classical guitars that I have either tried, looked at or worked on in my shop, I would say that it is a fairly even split between Brazilian and East Indian Rosewood. I have seen a of case where the builder stated that he uses Brazilian, but after a bit of prodding he admited that "oh, I may have used East Indian on that one..." Both can be finished to look very much alike but the fact is that simply stating that you use only Brazilian for your bridges has a definite impact on the mind of the buyer. In reality, I would be a bit surprised if 10% (or even 5%) of all guitar players could tell the sound differences between the 2 in a well conducted blind test.

In a recent recent GAL Convention (see GAL Magazine of Spring 2009), this question was put on a panel of experts: Brazilian and East Indian came out pretty much even. Most agreed that weight and design are the more important concerns.

I use East Indian for a reason: consistency. I buy large pieces of EIR and cut all my bridge blanks from it, so the density is always very much the same (meaning with my usual bridge design, they always come out at the same weight and stiffness). I guess if I could buy a large piece of Brazilian, it would do just the same, but these suckers are pretty expensive and hard to find.

Cheers

Pat
Author:  Carey [ Mon Jun 22, 2009 8:23 pm ]
Post subject:  Re: Classical Bridge Material
-fwiw, Segovia's 1937 Hauser ("the guitar of the epoch"- Segovia) has an
East Indian Rosewood bridge, according to Richard Brune. Good enough for me.
Author:  Carey [ Mon Jun 22, 2009 11:26 pm ]
Post subject:  Re: Classical Bridge Material
Filippo Morelli wrote:
Carey wrote:
-fwiw, Segovia's 1937 Hauser ("the guitar of the epoch"- Segovia) has an
East Indian Rosewood bridge, according to Richard Brune. Good enough for me.


For that matter, many of that period guitar were B&S of EIR.

Barring any other information, the standard answer to a high end classical guitar is BRW
for the bridge.

Filippo



-The guitar mentioned above was made with Brazilian back and sides, as
were most top quality classical guitars until at least the late 60s, Fleta being the notable exception- and he used Brazilian on occasion also.

Not sure what 'barring any other information' signifies. :)
Author:  Alan Carruth [ Tue Jun 23, 2009 1:30 pm ]
Post subject:  Re: Classical Bridge Material
Size, weight, and stiffness of the completed bridge are most likely the primary considerations, with damping of the bridge material possibly being a factor as well. Given the CITES issues with carrying things across the border, I've pretty well given up on BRW for bridges. Any of the rosewoods will work about the same, IMO, if you're careful in selecting the piece.

African and Indian ebony are quite dense, and have relatively high damping. It's difficult to keep the weight down in the 16-24 gram range with them. Macassar is a bit better.

Walnut and like are usually much less dense, and tend to make a bridge that is on the light side. This will certainly bring out the trebles on the guitar, if that's what you want.

There's a lot of debate abut what the properties of a good bridge 'should' be. I suspect it depends a lot on the top it's glued to, and the box that it's closing up. It's hard to do good science on this sort of stuff: sorting out variables is a trick. I think we're making progress, but it's slow.
Author:  Dave Fifield [ Wed Dec 30, 2009 11:11 pm ]
Post subject:  Re: Classical Bridge Material
If I may, I'd like to piggyback on this question with some more classical bridge questions of my own.

If using BRW for a classical bridge, what weight should I aim for (in grams)? And is this measured with the bone strips in place on the tie block or not? With the saddle or without?

I'm nearly done making the bridge for my first classical guitar (yeah, it's taken way longer than I thought it would to make!). It just needs tidying up and sanding a little more, then shaping to the guitar body. It's BRW with cow bone tie block strips. Right now it weighs 23.04g and has nice tap tone (like a marimba bar!).

Image

Is this about in the right ballpark? Should I try to shave some more off (from areas where strength isn't a big issue?)?

All input welcome.

Thanks,
Dave F.
Author:  patmguitars [ Thu Dec 31, 2009 12:13 am ]
Post subject:  Re: Classical Bridge Material
Hi Dave

The weight includes anything you add to it, as is this case with the decorating bone strips.

Standard bridge weight for a classical is between 18 and 25 grams. With lattice and double top designs, some luthiers bring it down to 13-14 grams.

The weight of the bridge must be considered in relation to the overall design of your guitar. A heavier bridge will in theory improve sustain, but may have a negative impact on volume. A lighter bridge will in theory allow more volume, but decrease sustain. Again, this is all in relation to how you built your guitar, and there are dozens of factors to be considered.

My recommendation is to go for a compromise at first. 20 to 22 grams is a fairly safe way to go. I have learned that it's better to start an experiment at the middle of the road, then slowly stretch the envelop rather than the other way around. If you sand you bridge a little more and it comes down to 21 or 22 grams, you should be OK.

My 2 cents.

Pat
Author:  fric [ Thu Dec 31, 2009 2:27 am ]
Post subject:  Re: Classical Bridge Material
hi,
till last three I always use IR , now I use Paduk.
becouse of my brace patern this bridge have 13gr.
Fric
Author:  Alexandru Marian [ Thu Dec 31, 2009 3:35 am ]
Post subject:  Re: Classical Bridge Material
Dave, it will end up down to 22 with some clean-up and it will probably be just fine since it is the middle of the interval more or less. You could round the saddle block ridges more, and try to flatten the tieblock more with a file. Also file the slopes of the wings (not the top) near the bevel to bring the bevel shape closer to a real, bigger circle. You can also file a rounded trench at the exit string holes. This will save some weight and relieve some of the tension off the back seam.
Author:  Alain Moisan [ Fri Jan 01, 2010 10:49 am ]
Post subject:  Re: Classical Bridge Material
I use almost exclusively honduran rosewood for bridges. Very low damping, looks good, and I've had the best result (sound wise) with it.
Author:  Ray Pepalis [ Sat Jan 02, 2010 9:17 am ]
Post subject:  Re: Classical Bridge Material
I'm recovering from a Mini Stroke, or a TIA episode, and am anxious to get back to building.
I'm starting a Classical with African Blackwood, and P.O. Cedar top.
I have an AFB bridge blank, but heard that it is too heavy, and not advisable.
If the AFB bridge is not recommended, where can I find a Braz. Rosewood in a very dark color that would look right with the AFB B&S.

Thanks and Happy New Year,

Ray
Author:  Christian Schmid [ Sat Jan 02, 2010 11:09 am ]
Post subject:  Re: Classical Bridge Material
Filippo Morelli wrote:
And how do border folks distinguish a BRW bridge from an EIR, coco, et cetera bridge?


Here's the CITES wood identification guide (BRW is on page 128)
http://www.cws-scf.ec.gc.ca/enforce/pdf/wood/Cites_Wood_Guide.pdf

From the guide (Message to customs officers and other inspectors responsible for enforcing CITES):

Quote:
The CITES Identification Guide – Tropical Woods was specifically designed to enable you to identify tropical woods protected by CITES (see ). The use of the guide requires no prior knowledge of wood identification. By following the steps described in the guide and using your powers of observation, you will learn simple identification techniques that will help you to identify CITES-protected tropical woods.
As you will see, you will not be able to identify all woods to the same degree of precision. While you will often be able to identify the genus, you will sometimes require the help of an expert to identify the species. In most cases, the guide will enable you to confirm the identification of woods accompanied by CITES permits and to ensure that woods that are not accompanied by CITES permits are not protected by CITES.
You should also be aware that the identification technique can be used to identify logs and lumber but not veneer, plywood and most products (e.g., guitars) or derivatives.


Christian
Author:  Dave Fifield [ Sat Jan 02, 2010 8:56 pm ]
Post subject:  Re: Classical Bridge Material
Thanks for the tips Pat/Alexandru - most helpful!!

I spent some time earlier today fitting the bridge to the guitar body. I had to take quite a bit of material off. It was hard holding onto the bridge while trying to apply even pressure to the sandpaper on top of the guitar, so I made a small holding tool. I had to finesse the block sizes on it so that the sanding pressure would be even across the whole bridge, but it didn't take long to make. With this tool, the bridge shaping went much quicker and smoother. Here are a few pictures of the bridge sanding holder (click them to see the hi-res versions):

Image

Image

Image

After clean up and finish sanding, the bridge now weighs 18.38g and is a perfect fit on the soundboard. I'm happy with that.

Image

Now on to finishing this guitar!

Cheers,
Dave F.
Author:  Alan Carruth [ Sat Jan 02, 2010 9:51 pm ]
Post subject:  Re: Classical Bridge Material
My problem with using BRW for bridges is that I exhibit at the Montreal festival, and have to carry guitars into Canada. Some of my customers are Canadian, and some others tour into Canada. Perhaps the chances of getting caught are 'small', but there's still the chance.

My understanding is that the chances of getting caught are about to rise significantly. There is currently a simple chemical swab test that can differentiate some types of rosewood. I'm told that they expect to improve that within this year to the point where border guards will be able to reliably and simply distinguish BRW from others. At tha point BS about 'Madagascar' or 'Cocobolo' will be moot.

I did read an interesting article in a compilation the other day. It concerned using Carbon 14 testing to date recent objects. There was a large spike in C14 in the late 40s, and 50s, which has been dropping off since due to the fact that atmospheric nuclear tests have stopped, and burning of fossil fuels has released a lot of C12. It turns out the the ratio of C12 to C14 in living tissue reflects the relative concentrations that prevailed at the time it was formed. Thus, wood from 1945 will have a much lower proportion of C14 than wood from 1948, and so on. The characteristic ratios prevailing at specific times are known, and have been used to date tissue samples to within a few _months_.

The drawback is that this sort of test is expensive. However, it brings up the possibility of other tests that could, perhaps be less costly. Do other widespread chemicals leave behind signatures? DDT was practically ubiquitous, at one time: does it leave traces? Dating by tree rings is, I believe, nearly useless on tropical woods, since they lack pronounced annual rings. Might this sort of test be a reasonable proxy? If you can prove that the wood in your guitar was cut before June of 1992, it's legal. The issue, for many of us, is that we cannot prove that legal wood is legal, which renders it illegal.

It's just a thought. The original article "The Mushroom Cloud's Silver Lining", by David Grimm, appeared in 'Science', Sept. 12, 2008.
Author:  Jim Kirby [ Sat Jan 02, 2010 9:57 pm ]
Post subject:  Re: Classical Bridge Material
The news about a reliable swab tests grieves me, as I'm just getting ready to ship my latest guitar (with BRW bridge and headplate) to Spain for my own personal use over the next six months. eek eek wow7-eyes wow7-eyes
Author:  Ti-Roux [ Sun Jan 03, 2010 12:58 am ]
Post subject:  Re: Classical Bridge Material
Nobody spoke about Snakewood...
It is one of the hardest wood you could find...
I never tried on bridge, but i could say, by having try some taptone on some pieces of snakewood... it rings like a bell!

Image
Image
Author:  Alexandru Marian [ Sun Jan 03, 2010 5:06 am ]
Post subject:  Re: Classical Bridge Material
My best guitar yet has a Brazilian bridge weighting more than 1000Kg/m3, as in very heavy. It ended up at 24 grams. I'm sure even the heaviest ABW or coco can be brought under 25 grams if the shape is refined enough.
Author:  David LaPlante [ Sun Jan 03, 2010 8:40 am ]
Post subject:  Re: Classical Bridge Material
In my most recent commission, sent to Japan last month, I used E.I. rosewood throughout in order to clear Japanese customs without problems.
I like E.I. for bridges as it is rather lighter than Brazilian and I have made a point to secure appropriate dark, well quartered, straight grained stock for them.
I don't weigh my bridges, but I'm sure they are quite light as I make them a bit narrower (26mm) than most and the wings rather thin and flexible which compliments the internal structure of the top.
Attachment:
#98Stookeybridge.jpg
Author:  Ti-Roux [ Sun Jan 03, 2010 10:18 am ]
Post subject:  Re: Classical Bridge Material
Snakewood is just a bit heavier than cocobolo or some other rosewood. On a size of a bridge, I don't think the extra weight is so important... For the sound, maybe my arms would take 1 or 2 extra grams...
Author:  WaddyThomson [ Sun Jan 03, 2010 11:56 am ]
Post subject:  Re: Classical Bridge Material
Here are my three.

Brazilian RW
Attachment:
BRW.jpg


Cocobolo
Attachment:
Cocobolo.jpg


Madagascan RW
Attachment:
Madegascan Rosewood.jpg


The differences in the look of the finished bridges is much different than when unfinished. They looked very differenb before finishing, Now, they look similar.
Author:  jeff [ Sun Jan 03, 2010 10:50 pm ]
Post subject:  Re: Classical Bridge Material
Here is another way to deal with the weight of snake wood. I used epoxy to glue the snake wood saddle and tie block to the canary wood bridge. Total weight 17 gms. I have had the guitar strung to tension with high tension strings for about eight months. So far so good. I cut the slots for the strings like a nut block before i glued the tie block to the bridge.
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