Graphite Bridge

[Joe F]

The leader of our local beginning bluegrass jam, who also has some luthiery experience under his belt, is making graphite replacement mandolin bridges. #They are machined from a single piece of graphite, including compensation steps and string slots, and replace the upper portion of the standard 2-piece bridge. #Visually, they are hard to distinguish from the regular ebony (or black painted) bridge.

I'm looking for ways to improve the volume on my 20-year old Japanese Kentucky KM-200S, and I'm strongly tempted to try one of these bridges. #Since I'd just be replacing the top portion, sanding and fitting a new bridge to the top wouldn't be an issue.

Do any of you builders have experience with graphite bridges? #What are the pros and cons of such an upgrade? #Any potential problems with a hybrid (graphite top, wood bottom) bridge?

[sunburst]

The great thing about something like that is... you can always change it back if you don't like it. Go ahead and try it, if it isn't to expensive, and let US know how it works.

[evanreilly]

I had a graphite saddle made for an adjustable bridge. Broke lots of strings. Finally put a thin bone cap on it. As I recall, it was very harsh sounding. It is also a major challnge to work with; I had to buy carbide bits for the luthier who made it.

[Keith Newell]

I use an insert of carbon fiber in my bridges that I make. THis one pictured is visible but the ones since this one are in a machined out pocket inside the ebony so you cant see it.
Keith Newell
http://home.comcast.net/~mandolinkgn/wsb/html/view.cgi-home.html-.html

[Fretbear]

So Keith, what do you find the graphite does to the sound? I have been using a graphite nut for years....

[Keith Newell]

I think it does a few things. #1 have you seen a bridge that the maker tried to make light weight and after a few years it sags in the middle? The carbon fiber strengthens the bridge and keeps it from ever sagging.
#2- The sound is more balanced, meaning the difference in loudness from the E to the G string is more even.
#3- The clarity of the sound in my opinian is better.
#4- The ebony top on my bridge mellows the tone a bit compared to a full 100% carbon fiber bridge, its not harsh, but not dampened either. It is even louder than a one peice bridge like seen on Red Henry's web site. (Yes I posted the article about my one piece bridge there a few years ago).
I guess its the best of both worlds, string life is great because its not rubbing against carbon fiber but against ebony so it tends to slip easier and not get cut. It has great tone because the strings are on ebony but immediatly supported by a very good sound transmitting and ridgid material and because of that I think more of the sound is transmitted through the bridge and its more even, meaning if the E string is struck the whole bridge responds more evenly rather than the treble end responding and the base end responding much less.
Please remember that this is not scientific, this is my opinian, but I can back it up with mine and several friends listening to the difference as I play in sessions about 1 to 2 times a week and have them say " wow, that thing is really projecting tonight" etc.
Keith Newell

[evanreilly]

That looks like a very good compromise of materials.

[thunderplucker]

Back in the days of testing materials for my fossil walrus ivory bridge saddles, I included graphite in my tests. Of all the materials I tested, I liked the graphite second to the fossil walrus ivory. It has a better tonal response than ebony. I think it is a great material for bridge saddles. It is not quite as hard to carve as you woulf think, Evan. I say go for it. Be aware that all mandolins will react a little different from each other and tone is a very subjective thing. The one consistant non subjective thing I learned about graphite is that it increase volume and made the tone brighter. Just my $.02 on this one. I encourage everyone to try different things and establish the tone that works for you.

[Joe F]

Update: #At the jam last night, the guy who makes the graphite bridges installed one on my mandolin. (I had talked to him the night before, and gave him measurements of the existing bridge). #I immediately noticed a significant increase in volume, and after playing it for a while, the overall sound seemed brighter. #I've had the same set of J74s on the instrument for about 4 months, and it sounded as if a month or two of age had been shaved off.

I'll try to post a picture later today or tomorrow.

[Joe F]

Here's a picture of the new bridge.

[ericwall]

Interesting line of posts. While at Wintergrass this year, I was complaining to Greg Fisher about my Lebeda F5. I was looking for a woodier, louder tone. He asked if he could borrow it for a few minutes and slapped on a graphite saddle in palce of the ebony one. It made a huge difference in volume and tone. I'm still not sure that's what my ear wants but it did open me up into the concept of small chnages to an existing instrument may really improve what you are after.
I still went out and bought an unfinished Brock F5 that put a great hole in my pocket!

Best!

[Yonkle]

It is amazing what a bridge can do. I strung up my new mando in the white 2 weeks ago, with a Loar style bridge, and it was loud. Then I did the finish and lacquer and I bought a Brekke Bridge in the meantime. I put on the Brekke and I liked the tone but the volume was low. I thought maybe it is just because of the lacquer and new strings ect. I played it for a week or so now, and did a few more adjustments. Tonight I put the first Bridge back on and,,,WOW Loud and clear, sounds and plays much better. I know a lot of folks like the Brekke, thats why I tried one, but on this mandolin, I am sticking with the Gibson Style, I guess it does pay to experiment! JD

[Joe F]

I knew that the graphite bridge would improve the volume, but I didn't expect the difference to be so dramatic. #I guess it makes sense from a structural mechanics point of view: #The lower mass and higher stiffness of the graphite absorbs less energy from the strings, and thus more energy will be transmitted to the top.

[JDARTGOD]

The Iboney saddle I had made a couple of weeks ago has given the Flatiron F-5 Special alot more clarity. Chop is still woofing along nicely, but the lead notes are more clear. Thinking about trying some Flattop strings.....I'm usually using the D'addairo Skaggs/Grisman/or McCoury set. (not sure of the J numbers....72 and/or 74http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif)

[Kevin K]

I've been tossing around making an Iboney saddle too. He sent me a big enough piece to do it but just never took the time. JDARTGOD, what was your process (holes, slots, etc) that you used?