Glueing fretboards for bolt on necks

This may seem like a silly question,but when using a bolt on neck,am i right in thinking that where the fretboard sits on the body it isn't glued down?.It would seem logical to me(otherwise not much point using a bolt on joint if it's glued as well),but unless there is absolutely no gap under the fretboard couldn't it vibrate when played?
I've just got around to attempting my first "proper" uke build(i've done a Tambourine banjo uke and a homemade backpacker),but a figure of eight build is proving to be a whole different level of work.
Cheers for any advice.

Some glue the extension down and some don't. Some say gluing helps transmit vibrations better which I suppose it does. Whether it matters or not is debatable. On my early builds, I used to leave the extensions un-glued for a while until I was sure the neck set was stable with string tension. I never heard any difference in tone when I glued them down so now I don't bother.

I build 14 fret tenors with about 1/2" cantilevered over the body. I do not glue it down. I leave a small space so as to prevent any buzz potential. I will build a larger fret board someday. I will cantilever it the same way as Rick Turner and others do. Also my understanding is, this also gives your sound board bigger chance for it to vibrate as much as possible. Last of the reasons I do not glue a fretboard is the neck is no longer a bolt on. It is bolt and glue on.

The trick to cantilevering is that you have to put carbon fiber under the fingerboard to support that projection.

I do not believe in the "neck/fingerboard transmission of vibration into the body" theory. It just doesn't hold up when you look at alternatives. And, if anything, gluing the fingerboard to the top prevents the upper bout from vibrating effectively.

Just my way, just my opinion, your mileage may vary.

But...the real player Martin ukes are the simpler ones with the very short fingerboard extension. Now why would that be?

They just had that magic moment back at the start of the 20th century where they simply got it right. Ken Timm's facsimiles of these early soprano ukulele prove the point - you make 'em as best as you can exactly like the originals and you come within a whisker of that vintage sound. I've made many Martin repros and they really hold their own against the originals tho I couldn't beat the canon of a 1926 #0 I had in for repair one time that was excellence on steroids! It defies understanding Rick because it just is the perfect combination of form and function. I've payed hundreds of the beggars and I am blown away nearly every time - hand built too LOL

So, who glues fingerboards anymore?



As Rick has said, doing it this way solves a number of problems.

Pete, you're actually making my point...The Martin O's and 1's, and the vintage 2's have the short fingerboard...and they sound better than the 3's and 5's. The tops are more free to vibrate.

When I designed the Compass Rose ukes, I'd already been freeing the fingerboard extension on my acoustic guitars by cantilevering it. I knew it worked, and there is close to 200 years of precedence doing this going back at least to Stauffer. So it's actually a traditional way to build, though rare. With some modern technology...carbon fiber...it works better than ever. And then my good friend, Ukulele Dick (aka Rick McKee), a fabulous uke player and collector (about 250 vintage and new ukes in his collection here near Santa Cruz), told me that the best sounding ukes did not have a fingerboard extension glued to the top. Bingo...for me it was a no-brainer to just apply that cantilevered fingerboard concept to a tenor uke design, and now to my concerts and baritones. It gives the best of both worlds...more vibrating area plus the extended note range.

Of course many of the early Hawaiian ukes didn't even have separate fingerboards...the frets were just banged into the top surface of the neck, and the 12 fret went right at the neck to body joint. The couldn't exactly saw fret slots in the top...though that was done on some early lutes.

On balance, I'd say that Rick's method isn't any more work than doing it the conventional way and maybe less. Installing the CF on the underside of the board isn't difficult or time consuming.

While I don't have much experience with vintage Martins, I do have two Timbuck faithful repro soprano Martins, and I love them both. One is 0 style (mahogany body and sides) with a fretboard that barely extends onto the body, and one is a K2 style (koa body and sides) with a 17 fret fingerboard that extends to the rosette and is glued to the soundboard. Despite or because of the differences, it is difficult not to compare the two. When I asked Ken on the forum about the tone (as the extended fretboard "deadening the vibes" had been brought up) his reply ended with:

" ...my style "O" ukes are louder ...But some folk listen with their eye's and dont care about stuff like that." So true.

When I show them to people, invariably they gravitate to the K2 - it is stunning, but so is the 0 stunning in its simplicity - I think the bling factor is at work here (nice binding, fancier rosette, cute little heel cap). But when they play them or ask me to, two things happen: first, if they ask me to "demonstrate" they are very disappointed in my playing. And second, their eyebrows go up when they hear the 0 style.

Don't get me wrong, the K 2 has a beautiful tone and a respectable sustain - it is a great ukulele! But there is something about that 0 style.... It's almost like it's alive and wants to sing. (Sound samples to follow in the near future, I promise).

So, koa vs. mahogany aside, is it the glued-down fretboard that makes the difference? After reading this thread it seems likely? (One more time - I am NOT disparaging the K2! Having a preference for one needn't undervalue the other.) In the thread about the K2, when asked if the extended fretboard "deadened the vibe" the response was....

" ..You may well be right about the fret board Killing the vibes but if 17 frets is what they want..I'm not going to argue about it this is an original Martin that I'm styling this one on."

You can have it both ways! Free the last five frets...or more!

When the fretboard is cantilevered over the top and not glued down, is the CF reinforcement a sheet type glued to the underside or is it a small tube slotted into the underside?

Have a look at post #20 on this page:

http://www.ukuleleunderground.com/forum/showthread.php?75083-The-Cherry-Bari/page2

To get enough stiffness, you'll make the CF as thick and wide as you can.

I use 1/8" x 1/2" CF bar dadoed 1/16" up into the fingerboard and 1/16" down into the neck. Then we relieve a bit of it under the fingerboard extension to get the clearance we want. It's amazing how stiff that fingerboard is. When first doing these (with guitars) I tried connecting the fingerboard to the top with a small rod to see if that would change the vibration coupling from fingerboard to the top, and I could hear exactly the opposite effect from what you might expect...the coupling damped the top in the upper bout. That was the final proof for me that the vibration coupling that counts is only happening at the bridge, and that the idea that the neck transmits significant vibration to the body via the neck joint or fingerboard, be it a guitar or uke, is an old and weary luthiers' myth.