Glue the tongue

[Zen]

Is the tongue of the fingerboard always glued to the body even when its a bolt on neck on a parlor size ? I'm ready to attach the neck and held back from gluing anything until now in case i would need to pop the neck on and off for adjustments etc. Everything is ready and I have the bridge attached and drilled and a finish applied so my final step now is attach the neck and string it up. So two bolts to tighten and thats it but need to know if I should glue the tongue or should it be left sitting tight on the body instead ?
Thanks

[tippie53]

I do add 1 drop of glue. If you are not bolting the extension you should have something there.
You can bolt it on dry and see how it goes. If you have a buzz you can't Identify it may be the extension

[Darryl Young]

Rusty, I don't think it's required (or at least I have a guitar that has been strung up for 3 years or so and the fretboard extension still isn't glued). However, I'm thinking glueing the extension adds a little more resistance to neck movement/rotation so I think it's a good idea. It was my first guitar and I had little experience setting neck angles so I wanted to be able to make future adjustments easily. One day I plan to tweak the neck angle a tad lower and glue the fretboard extension in place.

Here's a thought (various opinions on this so use your own judgement). Sometimes a soundboard will split along the sides of the fretboard when it is glued in place. I don't believe there is a concensus on the exact cause of this but at least some believe it is sometimes caused by the difference in expansion rates between the thick, heavy fretboard extension and the light, thin, soundboard. Meaning when the humidity gets really low, the soundboard shrinks differently or faster than the thick fretboard and since they are glued together something must give......and the soundboard splits along the edge of the fretboard (again, there are various opinions on this).

If you believe the above scenario can cause (or contribute to) the soundboard splitting but still want to glue the fretboard extension, some folks use a weak glue that creeps easily, like Elmers, to glue the extension. The thought is it's better for the glue to fail before the soundboard has enough pressure applied to cause a split. If the glue fails, it can easily be re-glued with little trouble. Many apply the glue only near the perimeter of the fretboard and leave the bulk of the middle area unglued.

Just a thought.

[tippie53]

As Darryl points out there are time the top will split along the sides of the fretboard. This if often for one of 2 causes.
A loose neck block
B shear along the side of the fretboard
This will be because of the shear of the load or from contraction of the top against the fretboard.

I see this more on Martins than I do on Gibsons. I think one reason is the gibson often uses a single drop of glue on the fretboard tongue. Martin adds glue to the entire extension.

[Zen]

Many Thanks Guys --definitely food for thought !!
Rusty

[songman101]

Thanks for the glue tip John,

This is so important to keeping a fine instrument for decades .I have seen the split that being talked about and the thin glue and using just a bit to help...keep it sound is good advice for a newbie. Thanks Guys Steve -- songman101

[Tom West]

As Darryl points out there are time the top will split along the sides of the fretboard. This if often for one of 2 causes.
A loose neck block
B shear along the side of the fretboard
This will be because of the shear of the load or from contraction of the top against the fretboard.

I see this more on Martins than I do on Gibsons. I think one reason is the gibson often uses a single drop of glue on the fretboard tongue. Martin adds glue to the entire extension.

John: There is no doubt in my mind that on a well constructed guitar with UTB and Popsicle braces that the culprit causing cracking along side the fingerboard is shrinkage differential. While the shear load is significant, on well guitars constructed with fingerboard extensions not or lightly glued there is little evidence of cracking. I do think that this leads to a slight lessening of body stiffness and earlier neck resets. Just my opinion of course.
Tom

[tippie53]

shear can be caused by shrinkage or pushing. I agree most of the cracking is caused by the shrinkage effect. That is still a shear force . As the top and fretboard move at different rates that edge along the fretboard will split.

[Zen]

Hi Guys, Are we talking about the fretboard splitting here ? Can anyone post a pic to give us an example of what to look out for.
its something I would never have thought about so thanks for the info
Rusty

[tippie53]

Not the fretboard but the top along the sides of the fretboard.
Conifers like spruce will expand and contract more than ebony will. There are a few forces at work here. The shear force of the fretboard as it is being pushed into the neck is usually handled by the braces. Neck block , transverse brace and Popsicle braces.
In 1939 Martin redesigned the Dred braces and shrank the neck block from 1 9/16 in to 1 3/8 in. Also the transverse brace at this time was about 3/8 wide not the 1/2 in we see today. What happened was that the shear forces and possibly the shrinkage tended to crack the top and drive the upper part of the top into the sound hole.
http://www.frets.com/FretsPages/Luthier ... rack1.html
while not a martin this is not uncommon.

If left unrepaired the top will cave into the soundhole.