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I've done it both ways, which is more common and what do you do? If I fret first, there is more neck mass to prevent the frets from introducing a back bow but what are the chances of the neck moving when I shape the back of the shaft and remove that mass?

I should have mentioned that this is Spanish heel construction with the neck already a part of the instrument.

After.

I'm not going to pretend that I have a lot of experience with classicals. I've built exactly one of them. But I've built several other instruments and I've come down to fretting all of my fingerboards before I even glue them to the necks. I leave two slots unfretted. Those are for my registration pins. They get fretted after the fingerboard is glued to the neck (whether a bolt on neck or a glued dovetail joint. I should also say that I put my locator pins in the second or third fret back from the nut and in whatever fret is over the heel of the neck. That way, I can support those areas with pads, wood blocks, etc., while setting the last two frets. Even then, the back of my neck is unshaped until the fingerboard (including all frets) is on. This is to prevent dents or other unanticipated damage to the freshly shaped neck back. Just save that until after the fret job if you can.

I too fret my fretboards before I glue them down. But also pretty much carve the necks before I glue them on.
I know in Bogdonovichs book he shapes the heel and head then later cleans it up. Does it make a difference? I sometimes do things just because I can. It's a free world anyway whatever floats your boat is cool.


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Do a dry fit of the finger board to the guitar, and verify that the neck angle is correct. Glue the fingerboard. Add any radius you want. Check it for flatness and proper projection (neck angle). (For an 8mm bridge, I want the projection at the saddle position to be 4.0mm on the bass side, and 4.5mm on the treble--measured off the top of the guitar with no frets. Carve the neck, leaving it a mm oversize. Refine the fingerboard surface in preparation for fretting. Install the frets. Finalize the neck carving. Mill, crown and polish the frets. If you're careful along the way, the final fret mill will remove only .001"--more than .003", and you've done something wrong.

My fingerboard is already glued down and the width of the neck is now flush to the edges of the fingerboard. My fingerboard is already tapered for the correct neck angle. I have decided I am going to fret before carving the back of the neck. My new question is: with that extra neck mass for support during fretting, do I make the fingerboard perfectly flat or do I need to scoop from the 5th to 12th fret to compensate for back bow introduced from fretting?

Can't hurt to leave it thick while fretting. Might even be a good thing to keep the neck a little stiffer while doing that job.

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Waddy

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I think the scoop you are talking about is called relief, not really to compensate for back bow caused by fretting. It gives the strings a bit more space to vibrate where it is needed. I always fret last, why give up the chance to make fine adjustments to the fret board including changing the effective neck angle until the very end. My guitars are completely finished before I fret.

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Fretting introduces the same stresses whether or not the neck is carved.

If you fret first you're less likely to see the practical effects of those stresses as the whole structure is much stiffer before carving... If you start with a carved neck you can very easily see the effects of fretting on the curvature of the neck.

In theory if you get the slots and the fretting right it shouldn't matter which comes first.

Wood can have internal stresses that you might want to know about before fretting which will reveal themselves once the neck is carved.

In the end you have to weigh these facts against your process, your experience and what's easier for you to get right, and what you want to test/learn to determine the right answer. It's worth thinking through IMO.

Give the board a bit of scoop. Around 0.2 -0.3 mm's on the bass side and a touch less than that on the treble. I can't remember getting a back bow on a classical, including refrets. Of course that might depend on how tight the fret slots are and the particular wire. I use a saw that gives a slightly wider kerf than the usual fret slotting saws so it's much less likely that I'll see a back bow anyway.

I build with Spanish heel, both classical and SS. I now do all fretting after finish -- makes cleanup of the fingerboard and accurate fret levelling much easier. All my fingerboards are bound, so no tang ends to deal with.
After glueing on the fingerboard and shaping the neck, I level the fingerboard and radius (classicals have a uniform taper on the bass side). Then I mask and finish.
The fingerboard is easily cleaned up after finish, fretted and frets levelled, before setting relief under tension (I use a 2-way rod - you can also pre-tension a one-way rod to get 2-way adjustability).
I've done the steps in different order, but this is the sequence I've settled on.


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I have had necks bow slightly after carving them, in those cases no problem leveling the fret board after the neck settled in. I would rather take it off the finger board than the frets.

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I agree with James. Seems to me that if you fret the guitar with the whole neck that when you start removing wood to carve the neck shaft then the neck will begin to react to the stress. So IOW it won't matter. I've done it both ways but now prefer to make fretting the last thing I do.

Back to being totally undecided! One of the disadvantages (or advantages) of access to so many opinions here.

I glue my fretboard (pre-tapered), trim the neck flush to the board (as you have done) and refine it to dead flat from end to end (a tiny bit of radius side to side) by sanding with a long wooden plane body as well as scraping the high spots with my Mora knives. I mask the top off with cardboard mostly to keep the fine ebony dust out of the spruce.
I avoid any back bow by carefully matching the fret wire to the slot.
I'm using a .023" slot matched to .0185" fret wire thus the only the bead is holding it and exerting little if any wedging effect (negated by the stiff uncarved neck shaft).
Once carved the neck remains flat and pulls up into the proper relief with string tension.

Thanks David for that information. I am using a preslotted board from LMI which is supposed to be slotted to .023 They list the tang width on the fretwire I have as .020 and the stud width as .032. I practiced a little on a scrap old fretboard from them this weekend and I pressed the barbs a bit with a modified pair of glass pliers and used 1 quick stroke of a file and they went in nicely. I also was using my new 5oz Stanley deadblow hammer which was a huge improvement over my fretting hammer. I'm still undecided about carving before or after. I think part of my indecision is that this is a birds eye maple neck which is riftsawn. The neck up until now has remained completely stable, even through some wild swings in humidity before I used it. I have never used maple for a neck before, and people here have scared me about it being riftsawn, so not sure what to expect. My other necks have always been Spanish cedar or mahogany.

I can only remember one time that a neck moved after I carved it. I took out a few frets and rescraped the board and it was fixed. All may be fine even with the maple.
I didn't mention it before but I like the stability of the uncarved square neck shaft in driving in the frets, I use a block of mahogany on my bench under the neck as I go up and a metal dolly under the extension.
The fret "Barber" from Stew Mac is also a great gizmo for modifying the bead size for varous applications. I'm now using it to make the frets over the body a bit easier to seat. I first used it on a Tornavoz guitar where all the frets had to go in without access to the interior.
John Hall on this forum has taken over the selling of the various tang sizes that Martin used to have available, very important especially in the repair of old Martin guitars and useful for the rest of us in tailoring the tang and bead size to slot size.

Any danger of back bow disappears when you move to a slightly wider slot and/or narrower barbs/fretwire.
If you fret a board (off the Guitar) with the standard fretwire and using the standard slot it results in a fretboard that has a huge back bow. Increase the slot by a touch shy of 0.1 mm and that back bow is significantly reduced. It makes sense that it's effect on the Neck is going to be that much less. I use Fish glue (Hide works too), to take up some of that extra space and 'lock' the fretwire. I usually hammer and then clamp the frets with wooden blocks (until the glue has dried) but I have tried it without clamping and the frets held fine. Once the glue has hardened the frets aren't going anywhere. To remove them I have to use a damp cloth and soldering iron to steam the glue soft. Even with the wider slot you can still pull chips out of the fretboard, so the slots still need the edges spoiling with the three cornered file.
The frets hammer in a little easier than the standard method. It's not much different to David's 'over the body frets', except that he's altering the frets, I alter the slot.

Great thread! Thanks, Wendy.

Best wishes,
Max

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Max Bishop
Brighton, Michigan

I'm in the "fret last" camp, often even delaying it until after the first string-up. I'd hate to try and carve a neck with frets on it... don't you ever snag on the ends of them when blending the edge of the fingerboard into the neck?

And I use the StewMac fret barber tool and/or a dremel cutoff wheel to grind down the barbs on the fretwire until it seats with a reasonable amount of force. Too much variation across different wires to do it any other way. I fill the slot with hide glue to minimize air gaps and help mechanically lock the fret in place. Especially with uke wire, which has a tang width as wide or wider than my saw kerf, so I have to grind the barbs off entirely and then make little divots to act as inverse barbs with the glue. Basically bar frets at that point

You can fret a board off the guitar and if it has back bow, put the ends on a 3/4" block and put a 5 lb weight in the middle. Next morning it'll be flat. Just takes a little time for the slots to compress to the frets.

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Waddy

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".. don't you ever snag on the ends of them when blending the edge of the fingerboard into the neck?"

No, by that time I'm using the file portion of my 4-in-1 file....................

Have only completed 7 classicals, but I've followed Cumpiano and Natelson from the beginning as far as when to fret. I fret first and then finish the neck. Thus far I've only used the Spanish heel with spanish cedar (4) and mahogany for neck woods (3). Haven't had a problem with back bow yet. Got a pound of fret wire (can't find the specifications), but its working fine with my LMI circular blade. I dress the slot with my triangular file and put a bit of Titebond on the frets as I hammer (gently) them in.