Troublesome geometry changes?

[Keith Somerville]

Hello, chaps.

This work was passed on to me by a local guitar shop yesterday and I thought I'd pick your brains before attacking it. I hope the photos will explain everything. It frets out very badly over the fingerboard extension which has humped up with the rest of the top. There are no obvious signs of wood movement elsewhere.

[Paul Breen]

Can you post a picture of what the straight edge looks like on top of the fingerboard to where it would meet the bridge? The images posted don't really give any clues.

[Keith Somerville]

Hope these help.

[Paul Breen]

It would also be helpful to see the straight edge from nut to end of finger board.

[Keith Somerville]

Hope you can see on this photo. The board is straight up to the 12th fret when it falls away. Resting a straight edge on frets 1-12 leaves the straight edge hanging about 3mm above the bridge. Resting it on the fingerboard extension leaves it hanging about .5mm above the bridge.

[Paul Breen]

The neck geometry doesn't look bad from the images. It's also rather typical to have the finger board extension fall away after it gets over the body on a dreadnaught. A player that would actually use those frets up there would be better off with a cut-away, where the falling off would be less desirable but this is common practice on a dreadnaught. The neck is over set just a bit but should still be able to be made playable. I'm guessing that the lay of the frets is responsible and a fret leveling may clean things up. Try checking all of the frets with a short straight edge that will only span 3 frets at a time. Check this strung to pitch and follow each string, checking every fret. Mark the tall spots with a marker and see what you get. My guess is sloppy or no leveling up the neck. Some manufactures just push them in and send them out with no leveling. 

[Keith Somerville]

I'm trying to work out how this has happened. To me, the neck angle seems totally off in that you'd need a saddle about an inch high. I haven't been able to get a hold of the customer, but I find it unbelievable that they would've bought it in this condition: at the minute frets 7-12 on the high E string all play E!

Tempted to hand it back as it's not a neck reset I particularly like the look of...

[Paul Verticchio]

Hi Keith.

Paul Breen gave you good advice about the fallaway. It's SUPPOSED to be there.

Disregard the measurements taken at the end of the FB extension. It simply isn't a factor in a setup.

Question? Is the instrument properly humidified. The frets 7-12 issue you mentioned are a classic symptom of a dry instrument.

If it needs humidified, do so ASAP.  I endorse Hesh Breakstone's method. It simply "WORKS". See the archives for more info on his methodology.

When humidified, level ALL of the frets with special attention given to retain the fall-away.  Recrown & polish and a perform a precise truss rod adjustment to allow for the standard .010" relief at the 7th fret and you should have a very playable instrument on your bench.

And... if the instrument is still wonky AFTER you do the humidification/level/polish, AND it's still under warranty, I'd suggest to the owner/customer to do a warranty claim on the instrument.

I'm always curious. What brand & model is the guitar?

Best of luck, man :)

[Mark Pollock]

Looks like the third picture shows a "Crafter" label. I am particularly underwhelmed by the hunk of plywood covering the truss rod that also appears to be under the neck block. Pass that sucker back to the owner.

[Hesh Breakstone]

The guitar looks dry to me....  I see the classic depression in front of the bridge and a lack of radius behind the bridge.  

Guitar dries out, top in the area of the bridge shrinks, saddle goes down too, action gets lowered and they start to rattle, buzz and fret out.

As Paul said the fall-away is supposed to be there and the slight dome in the area of the fret board extension is also likely supposed to be there too if the builder does not build with a flattened upper bout.  As long as the extension fits well this is fine.  I like to see fall-away too.

Not sure where you are (climate) or where the guitar is in terms of the humidity as well but my hunch is that this is simply a dry guitar.

Solution:  Bag it and tag it for three days and watch the wonders of proper humidity as the dome rises, saddle too, and with perhaps a truss rod tweak and maybe some sharp fret ends filed down it could be good to go.  By the way feel the fret ends from the sides of the fret board - if they feel sharp you have a dry guitar.

The more seasoned the top was or is... now the more likely it is to return to the original geometry when humidified.  If the top wood is not very seasoned the dimensional instability may be permanent and the fix might require a new saddle.

What brand is the guitar?

[Hesh Breakstone]

A little more background may be helpful too.  Many guitars these days are built with a slight dome on the top and a slightly more profound dome on the back.

Why?  Because for all of time that the acoustic guitar has been around they do suffer from the ravages of humidity swings.  When a guitar dries out the wood shrinks with the more seasoned the wood then less the dimensional instability.  

The classic "flat top" built entirely flat if the wood wants to shrink, and it can't because it's attached to the rim so what often results is cracking.

A domed top instrument will resist cracking to a greater degree but not entirely if permitted to get very dry and then cracking can result as well.

Domed tops are also stronger from an engineering point of view and have a bit more resistance to being crushed, sat on, etc.

It also has to be mentioned that nearly all large manufacturers have a bone to pick as well.  We like to think that job one for a corporation or large business concern is making money.  The better companies will instill in their workers that job one is actually shielding the company from unwanted liability.  In this case warranty claims...  Job two is making money.... :)

A domed top can withstand the ravages of abuse from being permitted to dry out better than a traditional totally flat top instrument.  They still can crack, they still can get proud fret ends and necks still dry out and the differential expansion and contraction rates of the fret board material and the neck material can still cause back bow in the neck when permitted to dry out.  But from a warranty claim perspective and even though letting an instrument dry out is very much considered owner abuse and rarely covered by anyone's warranty less cracking equates to less damage, less cost to repair, and perhaps better owner satisfaction.

Some small builders ship with two saddles knowing that in the winter in some climates the dome will be reduced enough to cause buzzing so they ship with a winter saddle, a lower saddle to compensate for this.  My guitars were always supplied with a winter and summer saddle AND a heart to heart conversation about how much care a fine acoustic instrument needs....  I included a quality guitar humidifier as well but I also made it clear that high performance instruments are not to be left in the trunk of a black car in the long term at LAX either....

In my experience since we have to explain the humidity thing to clients nearly every single day... folks just don't know that wooden acoustic guitars require a few hoops to be jumped though by the owners in terms of care and feeding.  

Instead many owners got the wrong impression from John Belushi at that toga party in Animal House....

[LARRY KLOSE]

Michael Hornick (Shanti guitars), who built my guitar, told me years ago that he had been the the on-site guitar repair guy for several years at the outdoor Telluride BG festival.  He said that he saw innumerable guitars (Martins, cheapies, you name it) that had the strings resting on the fretboard after a couple of days in the very dry, summer environment of the high Rockies.  He said that a day or two in the case with a good humidifier usually cured the problem if there was no structural damage.

Here in the desert Southwest, low humidity is a daily problem.  The outdoor daytime ambient humidity can be 5% for weeks at a time.  It'll be like that most days until the beginning of July when the summer monsoon rain season starts--when we have thunderstorms nearly every afternoon until mid-September.  Even with a whole house humidfier running every day from September until July, I've had to trim the fret ends on several of my instruments after they had been here a while--except for Michael's and one other really good one.  So seasoning and wood quality makes a difference.  I've also had the pitch of my (archtop) mandolin drop a quarter tone in just a couple of hours when I took it out of the house to play an outdoor gig during the dry period. I had to get a taller saddle from Michael for the guitar when I moved to Arizona from the SF Bay Area (where Frank Ford didn't even sell humidifiers when I bought the Shanti from his shop).

Larry

[Paul Breen]

"The guitar looks dry to me....  I see the classic depression in front of the bridge and a lack of radius behind the bridge."

Not something that would send a flag up this time of year in Central Illinois, plenty of humidity here. Winters on the other hand.....

Kieth are you in an arid region?