Bridge wood

[patdewar]

I've done some archive digging and can't find this exact topic (please direct me there if it exists).

I want to get the group's view of various bridge materials, but specifically softer woods.  I have some American holly that I use for bindings and some other things.  I just saw that Dana Bourgeois makes 00 guitars using holly as a bridge.  Not sure I love the aesthetics but I was intrigued and made a few blanks.  Anyway, just finished a "0" body all mahogany guitar and used a mahogany bridge.  It looked fine but split within a week.   So,...

Thoughts on less than hard woods for bridges?  Anyone else use holly?  Taking a non-tradition approach (vs. ebony and RW) seemed like a good idea but it sucks to pull a new bridge off a new guitar within a month.  Thanks

[Paul McEvoy]

there's a lot about this in the Gore book.

Notably I made a classical bridge for a guitar about 2 years ago out of Padauk and it just exploded but I think that might be from a glue starved joint.

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Paul McEvoy
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[Paul Slingerland]

I used holly on one guitar. It was an OM.  It looked great. After a year the saddle slot had deformed and needed a wedge to hold it vertical.  The customer brought it back and I removed it and replaced it with rosewood bridge that matched the fingerboard. 

I’ve had great luck with walnut, maple and wenge.

[Charles Tauber]

The starting point is identifying what you are trying to achieve with the bridge. Specifically, if you don't care about weight/mass, then any very hard wood will do, including rosewoods and ebonies. If you are trying to minimize weight/mass, then less dense woods could be worth exploring along with differing designs that facilitate lighter/weight and softer woods. 

The combination of material selected and design chosen must resist string wear/cutting, must prevent the saddle from leaning or distorting over the life of the instrument and must not split over the life of the instrument. Some woods just aren't sufficiently hard and strong to resist wear, prevent splitting and prevent the saddle from leaning, regardless of the design used. Balsa wood comes to mind, though I'm certain that a successful design could be created that uses balsa. Some makers/manufacturers use design features that facilitate the use of softer, lighter and less strong woods. For example, instead of putting the pin holes along a straight line, which can lead to splits between pin holes, some makers use a design where the pin holes are not in a line. Another example is leaving more wood between the saddle and the sound hole-edge of the bridge, to strengthen the saddle slot as well as using an enclosed/blind saddle slot rather than a through saddle slot. Gore details using alternate layers of carbon fibre and wood in his lighter-weight bridge design.

In short, both material and design need to be considered: one design that works well in rosewood or ebony might not work well in much softer, weaker woods, though some design changes could facilitate the successful use of those woods.

I haven't tried a bridge made of holly - I wouldn't like the aesthetic of a white bridge with a dark fingerboard - but have used padauk, walnut, rosewood, ebony, pao ferro, zebra wood and a few others. Many woods can be made to work if one chooses a complimentary design and chooses the materials carefully. 

Charles

[Joe Shuter]

I built a 100% Englemann Spruce tenor ukulele. Naturally it had an Englemann Spruce bridge. So far no issues. Scooter

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[pstreit]

Great topic - some years ago woodcraft had "Texas Ebony" (Persimmon) in their sale bin and I got some thinking it  might make good bridge stock. I made a couple of bridges and really like the material. It works just like a typical ebony, a little harder on the tools, dense, and buffs out to a lovely patina. In researching it, Persimmon is an ebony (Diospyros virginiana), Janka hardness - 2300 - and thus finds uses in mallets, golf club heads before composites, drumsticks, kitchen utensils. This is a persimmon bridge I just made. I like it as a great additional option to rosewoods and other ebonies.

Regards,

Peter Streit

[Doug Shaker]

Thinking about it, one might be able to make a bridge with softer woods, then soak it in low viscosity

epoxy to harden it up.  I'd rather not, but it is a possibility.'

-Doug Shaker

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[Charles Tauber]

One probably could, though it would likely only produce surface hardening as the epoxy wouldn't likely soak very far into the wood. That would still allow the wood beneath it to be crushed under localized loading.

But, why would one want to? For what purpose? Epoxy is heavy: if one is using a softer wood to reduce weight, then adding much of the weight back by adding epoxy, what was accomplished that using a harder, slightly heavier wood would not?

[Paul McEvoy]

You could potentially stabilize wood with pickle juice/vacuum epoxy but I tend to think of epoxy as overall being a plastic and having essential dampening to it.  This is just my jackass way of understanding things but I'm not super into large amounts of epoxy in the signal chain. 

I don't mind using it for braces or cf reinforcements because in that situation it's very thin and I don't think has much effect but I wouldn't use epoxy stabilized woods if I could avoid it.  

Paul McEvoy
207-699-9526

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[Doug Shaker]

Charles & Paul-

I agree with you, essentially. For my bridges, I use ebony or rosewood and occasionally walnut. The darker woods fit with my aesthetic and their physical properties are suited to the purpose. If I wanted a light wood for a bridge, I’d almost certainly use maple. I don’t think I’d ever want to use a soft wood. I was just musing on a way that might work if one was committed to a softwood bridge. 

Build on!

Doug Shaker

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[patdewar]

Folks, thanks for all the responses from the experts.  I lent out my Gore books and didn't reference them when I put the mahogany bridge on (another lesson "experienced" vs. learned).  I agree with everyone who brought up the aesthetics of many soft woods (especially the holly I was very curious about).  Like others I try to match fingerboard material with headstock and bridge when it makes sense and looks good.  It isn't about weight per se (to me) as I've used ebony, RW and recently osage orange bridges and was able to keep them all near or under 30 gms (I'm doing steel stringed guitars).  What I really found fascinating was such a high end builder as Bourgeois using holly.  I sent their customer support an inquiry but haven't heard back.  

Here's the osage orange bridge on an all-mahogany 12 fret "0" for one of my grandkids.

[Stephen Foss]

Folks,

I'll relate an experiment I did a decade or so ago to attempt to figure out what 'sound difference' different woods make for bridge patches. I used Stewmac's little bridge bolts (hollow bolts allowing for temporary attachment of bridges to a steel string guitar) to attach bridges made from different woods to the top. This was a surrogate to different woods for the bridge patch, since it's beyond my bag of tricks to remove/replace a bridge patch easily. This was done prior to the Gore/Gillet books came out - I didn't measure frequencies with a computer, just used my ears.

The guitar already had a maple bridge patch installed. I made bridges out of ebony, maple, East Indian rosewood, and ash (because I had some scrap ash plus it's hard). 

The ebony/maple bridge/patch combo sounded like one would expect (pretty even across my hearing spectrum). The maple/maple combo was most definitely more 'treble-y'. I speculate that maple absorbs the lower frequencies; doesn't pass them through like ebony or EIR does. The EIR bridge was similar to ebony, just 'mellower', if that makes sense. The Ash merely sucked all frequencies across the spectrum; truly made the guitar sound dead, like it was stuffed with old, well-worn, stinky gym socks.

I now have a good idea of what woods 'steer' the sound to what I want it to be. I use Ash bridges/patches for those folks I don't like (juuuust kidding!). The test guitar ended up with the ebony/maple combination and is still out there making music.

I hope this helps,

Steve

[Paul McEvoy]

My wild guess is that the specific species doesn't matter much at all but the density of the bridge and how's that's relating to the specific top of the guitar and the guitar as a whole matters quite a bit.  

Just a guess....

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Paul McEvoy
207-699-9526

[Charles Tauber]

The total weight of the bridge would be my guess as well. 

I recently made a classical guitar with oak back and sides. I used a walnut bridge on it. It had some issues, particularly intonation anomalies. To make a long story short, I tried adding mass to the sides and to the bridge. The results were interesting. The more mass I added to the bridge, the more the frequency of the top lowered. No surprise there. However, the more mass added the more the instrument sounded muffled or dead. With a 3 g mass added to the bridge, and 11 g added to the sides, the most blatant intonation errors were largely fixed. All of that is as covered in detail in Gore's books: while new to me, it isn't new. 

The point of my story is that adding/removing mass from the bridge can make a significant difference to the response of the instrument. Many have less formally discovered that by using different materials (masses) for bridge pins on steel string guitars. A few years ago, I tested PowerPins: they are about 6 times heavier than ebony and do alter the response of the instrument. The alteration can be good or bad depending on the instrument and one's tonal preferences.    

[Stephen Foss]

Paul,

"just a guess..." me, too.  

Charles,

As mentioned, at the time, The G/G books weren't out yet, and I don't have a copy (yet). I'll go dig through the scrap pile and, with any luck, I can find the maple and ash bridges and attempt to determine both the weight and density of them. I've got an ebony bridge ready to go on to the latest guitar. I'll report back my findings, for what it's worth.

Thanks,

Steve

[patdewar]

Folks, thought I would wrap this topic (for me) as I heard back from Bourgeois Guitars (They claim they've never had a customer issue with the holly bridges they use on some models).  Also, I was at a friends wedding in VT this weekend and was able to shoot over to Northern Lights Music in Littleton, NH.  Dan Sullivan had a very high end Bourgeois OM-45 with their English holly bridge.  As Charles mentioned, I'm not a fan of the aesthetics, but I guess some of Bourgeois's higher end customers like it (original price on this was $25k, reduce to $17k).  Picture attached (I hope).  I guess if I ever build a totally blond guitar I'll pull my holly out and see how it looks (before I glue it on) but I will certainly be prepared with its replacement.

[David]

I imagine that the holly is used to sort-of-recreate the look of old guitars that used an ivory (elephant tusk) bridge. It may not appeal to you, but there are probably a few guitarists who wear bowler hats without irony that would love the look. :)

-David

[Sean Gilbert]

It's not the look for me, but there will be some that love it.

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