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The process I've been following is to:
1) fit the neck and body joint 99%, then attach the fretboard while neck is detached,
2) install and level frets (neck still detached)
3) pore fill, then finish and buff the neck and body separately.
4) Then attach the neck, which requires the last 1% of flossing and fitting,
5) then glue the fretboard extension down.

I've got a "break" at the 14th fret where the fretboard drops away to follow the slight angle of the body. As such, fret buzz when playing frets 10 - 14. Does anyone else follw this process? How do you accomodate the geometry of those frets? Simply relevel as a last step (OK, not level, but "re-curve", taking out the abrupt break at fret 14??

Thanks!!

I always fret after finishing and after neck and body are assembled. For me that's the only way to get a perfectly plane fretboard surface and the lowest, cleanest action possible.
I know some install frets even before gluing the fretboard to the neck, but I assume to have a successful and fully repeatable process one has to have the geometry down 100% taking into accounts the little quirks happening when things get glued up together and brought under full string tension.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

What I conclude out of your explanation of the problem is that you have a neck hump, which is caused by the neck being installed with too much of a back angle. You need to shift it forward, either by ungluing the fretboard extension and flossing untill it's all strait, or find a way to shim the bottom of the neck heel (but that would be a bit ugly...). If the hump is not too bad, you could simply level the frets to eliminate the hump, but that can work only for a tiny hump.

Raising the saddle might help remove the buzzing between 10 and 14, but you will have too much of a high action from about 17 to 21. What is the current distance between the top and the strings at the bridge?

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

This may not solve the problem on your current guitar but I had that same problem on the first guitar I built, and did some research. The problem with adjusting the neck heel so the fretboard fits the top without a hump is, unless the top/side geometry is perfect, the fretboard/bridge relationship will be less than ideal, and you have to raise or lower the saddle to compensate, thus possibly losing optimal volume and perhaps action.

I glue on my fretboard to the neck, then put in the frets. I adjust the truss rod so the neck is perfectly straight, frets level. Once the sides of the box are sanded, I fit the neck to the body, and adjust the neck heel angle by flossing such that a straightedge laid on top of the frets will hit the bridge pretty much on the top forward edge with a fudge factor of about +1/16" above. At this setting on four out of five of the guitars I have built so far the fretboard will slightly rise away from the guitar top as it approaches the sound hole. One was perfect because of the top/side relationship, and I am going to try to make more like that one! (Part of it was trying to get the dome of the top to match, but that''s another story!)

Anyway, here is what I have done on the other tops. I have modified the procedure slightly to fit my way of doing things, but I basically do what is here:

http://www.kennethmichaelguitars.com/NECKSET.html

One thing I will warn: DON'T use a ROS to feather in the edges of the sanded area! On two guitars now (I learn slowly), the sander has grabbed the top edge purfling and ripped it completely away when it got thin, necessitating I rout out and install a patch, which is sometimes slightly visible. I now take my time and do it by hand.

I also do not sand it so that the fretboard lies perfectly flat, I try to get a very slight fall away so that I can get the lowest possible action with no danger of fret buzz.

This method is not noticeable at all when looking directly at the top, only when sighting down the neck can you see the edge binding becomes thinner as it approaches the fretboard. This may be unacceptable to many builders, which is cool, I know that for myself I can never hope to match the artistry I have seen from many builders, so I shoot for sound and playability first, and do it in most pleasing aesthetics I can!

I also lack the years of experience here, so others may have better suggestions, but this works pretty well for me, and lets me adjust the neck angle to the bridge.

Having said all of that, I suppose if the angle isn't too bad, one could adjust the neck heel so the fretboard does lie flat on the top, and then sand the underside of the bridge to get the right height in relation to the fretboard, but I'm not sure how thin one should go on a bridge.

Good luck!

Damon

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Damon Wack
https://www.facebook.com/LindamonGuitars

Thanks, Laurent. I may have to go back to that method. I had tried that on the first couple, and frankly was uncomfortable with files, sanding blocks, etc. next to the finished top; also getting the perfectly straight line along the fretboard after clipping the frets, I had to be so careful about dinging the top I thought there had to be a better way. Do you have tricks and tips for filing the ends of the frets without gouging the top? Thanks.

Corky: I use a piece of matboard cut to the shape of the top with a section cut the same as the fingerboard. Tape it on the top and work away with out fear of doing any damage.
Tom

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A person who has never made a mistake has never made anything!!!

Use whatever to cover the top and protect it right to the edge of the fretboard. Beware of some masking tape brands where the adhesive reacts with some finishes, I've never had an issue with 3M. I use aluminium flashing squares taped together over wide blue tape on the top, but that's because I use many different plantillas and bridge spacings. Otherwise it's easiest to make one big plastic cover the shape of the guitar, faced with cork.
To round the fret ends I use a triangular file with one ground edge, that's the one making contact with the wood, and a rounded tip. Before fretting make sure you slightly bevel the edge of the fretboard (where it meets the finish) with 220grit or whatever, that's usually where finish delams happen. I stopped using "real" steel wool long ago and now use the synthetic kind (maroon, grey and white) and then buff the fretboard. To avoid accidents, take your time, vacuum often and make sure to catch any debris (fret ends, fillings etc.).
I'm not suggesting fretting after is necessarily the best method, in fact I kind of envy those being able to fret before attaching the board. But then finish tends to gather around the frets edges and cleanup is necessary. Choose your poison.
Some builders fret "in between", say before the last two coats of finish, by attaching the fretboard extension with double sided-tape. Not a bad compromise if everything goes as planned (it almost never does).

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I have tried several different methods to get the geometry right in the FB extension area.
I used this method on the last six guitars & it has worked very well for me. (Your results may vary )
First, I should mention that I use a heel block with a 1/2" thick FB extension support which butts firmly against & is glued to, the upper transverse brace. To get this fit right, I glue the UTB to the rims rather than gluing it to the top. (I don't use a graft above the UTB.)
Once the rimset is ready to glue on the top & back, (but before notching for the brace ends) I lay a straight edge across the upper bout at the end of the fingerboard support "paddle". With a sharp pencil, I mark a line on the end of the paddle, at the bottom of the straight edge.
Then plane the paddle in a straight line from the top edge of the rim to the line. Leave the pencil line & a hair above it.
I then notch the rims & glue the pre-shaped upper transverse brace to the rims & the end of the paddle.
Once the glue dries, I touch up the UTB arch with the sanding dish, if necessary. I plane the arch away on the section of the UTB that is in contact with the end of the paddle, leaving a small flat section where the fingerboard will lay.
This sounds like an extra complication, but it has worked very well for me & doesn't take a lot of extra time to do. So far, it has saved me the frustration of dealing with the dreaded 12th (or 14th) fret hump.
Sometimes I need to lightly sand the top to get the right amount of fall away on the FB extension, but usually not.
(I do need to remind myself to place a few go-bars over the UTB when I glue the top on.)
Just one more way to skin that darned cat.

Thanks, all. Appreciate your insight. I'll let you know what I conclude once this thing is done.....

Update!

So, after getting the strings off, putting on the magnifying glasses and inspecting what was really going on here, I discovered that the 13th fret had lifted a bit, and was causing 90% of the buzz. Probably got loose when clamping the fretboard extension. Perhaps a risk of the fret first, then clamp approach.

A bit of carefully applied CA, a clamp, and a final pass with the fret file and steel wool, and I'm good to go! I've still got a very small amount of buzz on the high e string, but I'm hoping that the string tension will create just a little relief to cure the buzz.

Thanks for all your help.