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I am about to fret a guitar that I am building. Before I had attached the neck to the body, I radiused the fretboard and all was flat and straight - left at 120 grit for the time being. Now that the guitar is nearing completion and I am about to fret it. I am about to take the fretboard up through 150, 220 and 320 grits.

However, I have noticed that the bass side of the fretboard now has a slight bit of forward bow that I can slip a .005 gauge under while the middle and treble side of the fretboard are perfectly level.

I suppose the neck has moved some.. It is kiln dried cherry and also had sat around my shop for 8+ months prior to using it.

What would you do?

you mean the fretboard is coming unglued from the neck...?

If it fit before and now one has moved just a little, glue it up and don't worry about it. If it's already glued & moving, that's a bigger concern. Are you going to fret before or after gluing to the neck?

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

No no no. Not unglued at all. The guitar is totally done. Just needs to be fretted and finished. When I put a straight edge down the length of the fretboard there appears to be forward bow on the bass side while it is straight on the treble side.

Next time fret it before you complete the whole structure....

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"Act your age, not your shoe size" - Prince

i think what i would do is(assuming like most people you keep your guitar in a home, and not a carefully controlled chamber): when the humidity is at a moderate level(somewhere halfway between your summer and winter extremes), re-radius it, fret it, and hope the problem doesn't return too badly when the humidity shifts high or low again.
or, it may be that the wood is now finally stable, and if you re-radius/level, it will be ok from here on out... 0.005 isn't too bad;
or, it may be that the wood is still going to season and warp for a few years, in which case you are screwed

Is there a reason why you would fret it earlier? Fretting is usually the very last thing that I do before spraying lacquer.

Because it's easier?

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"Act your age, not your shoe size" - Prince

That's a matter of opinion....
It is also my opinion.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

In what way is it easier for you?

Do you fret the board before you even glue it down to the neck?

Always have. Never had a lick of trouble with that method of building.
Repairs are another matter, of course.

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"Act your age, not your shoe size" - Prince

I think that the reason I do it the way I do is because I want to get the board on the neck and then evaluate the flatness of the board and whether I'm certain it will have enough relief and so forth. I'd be afraid of clamping down a fretted board to a neck and discovering that the neck has too much backbow or whatever and not being able to solve it without pulling the frets and sanding the board.. Though I have sanded relief into the frets themselves.. but you can only do that a tiny bit.

Take a sanding beam and level the board, redo the radius and then continue on with the work. It's the same thing you would do if you were refretting a used insturment.

That's in fact the description of how to recognize a twisted neck.

If it were .001 or less I wouldn't worry about it but .005 is significant enough to affect action and setup. It must be remedied before fretting in this case.

My solution would be to use one of these: https://www.stewmac.com/shop/Fretting_s ... r=502.1884

It's long enough to cover almost the whole fretboard at once.

I use them when refretting guitars, they work great.

I'd wait and make sure the neck is done moving first, it sounds like the wood wasn't completely dry and at equilibrium.

It also could be that the wood wasn't sawn correctly and one side of the neck responds to changes in humidity more than the other.

I had this happen to me once when I made a neck out of solid ebony. I noticed the fret ends getting sharp after a few months, and the neck developed a slight twist. I refretted/reradiused after waiting two years for the wood to dry/settle or whatever, and I still have the neck as I never actually put it on a guitar after that, but the frets are not sharp anymore and the neck is still true, after roughly 9 years now, so I know the wood simply wasn't dry when I made the neck.

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Old growth, shmold growth!

Using any sanding technique to shape the fretboard you can sand the relief into the board prior to the fret installation. I do that via programming and cnc but there ought to be a conventional way of accomplishing this. Seems better to whittle this out of the fretboard than the frets.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

This is how my fretboard looks in the middle area on either side.

Is this a bolt on? If so, unbolt it and flatten the fretboard. If not, you could try to flatten it using the square metal stock/adhesive sandpaper technique. It's good that the frets aren't in yet.

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http://www.tinyhouseandland.com

Set neck. I'm going to give it some time before re radiusing. Clearly the wood has warped a bit. Probably wasn't fully dried. I just hope it doesn't continue to warp and twist farther.

A good idea.

If it wasn't fully dried it may continue to move a little, but the good news is that it should stabilize, and be okay once you straighten it after it dries.

I would also consider making sure the back of the neck is fully shaped as well, so that and stress in the wood will be relieved before the final radiusing procedure.

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Old growth, shmold growth!

Honestly, that small gap wouldn't worry me, I would wait a week before re-radiusing.

So I broke down and paid the $135+shipping for one of these bad boys. I have to say, it's already one of the best luthiery tools I have. Very expensive, but I really didn't want to spend the time making my own.. though I'm sure it could be done. I can already tell that this thing is going to bring a new precision and pleasure to my work.

These are pictures of sanding my slightly warped neck. In the second picture you can see the remaining pencil after a bit of sanding - demonstrating the warped board being remedied.

don't forget to support at the headstock/nut, ensuring that the neck/fretboard does not flex as you apply pressure with the sanding caul

I must say those are probably the best thing I've ever purchased from Stew-Mac.

Some of their items are a little gimicky, but those radius beams are serious tools.

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Old growth, shmold growth!

The other thing to watch for is that the fretboard doesn't get lopsided, IE one side too much thinner than the other.

It's not fatal, as the fret plane will be straight and even still, and I've worked on PLENTY of guitars, mostly from the Seventies for some reason, with tilted but consistent radii.

It's just something to watch out for as you are correcting a twist, which inevitably involves sanding some parts of the fretboard more than others.

I do this exact procedure, pencil and all, on guitars whenever I refret them, and most have a degree of twist to them, some extremely slight and others pretty bad.

In fact, one time I refretted a guitar that had been burned in a fire and the neck warped, but I was able to refret it, re-radius it, and make it play good as new.

It was an old Gibson.

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Old growth, shmold growth!

...and is that a douglas fir body...? sure looks like it to me