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Forward bow on half of fretboard. Straight on other half.
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Author:  Irving [ Fri Feb 22, 2013 1:04 pm ]
Post subject:  Forward bow on half of fretboard. Straight on other half.
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?
Author:  nyazzip [ Fri Feb 22, 2013 1:57 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
you mean the fretboard is coming unglued from the neck...?
Author:  Rodger Knox [ Fri Feb 22, 2013 2:05 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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?
Author:  Irving [ Fri Feb 22, 2013 2:19 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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.
Author:  Chris Pile [ Fri Feb 22, 2013 2:43 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Quote:
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....
Author:  nyazzip [ Fri Feb 22, 2013 3:00 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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 :D
Author:  Irving [ Fri Feb 22, 2013 4:06 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Chris Pile wrote:
Quote:
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....


Is there a reason why you would fret it earlier? Fretting is usually the very last thing that I do before spraying lacquer.
Author:  Chris Pile [ Fri Feb 22, 2013 4:11 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Because it's easier?
Author:  Rodger Knox [ Fri Feb 22, 2013 4:53 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Chris Pile wrote:
Because it's easier?


That's a matter of opinion.... beehive
It is also my opinion. bliss
Author:  Irving [ Fri Feb 22, 2013 4:57 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Chris Pile wrote:
Because it's easier?


In what way is it easier for you?

Do you fret the board before you even glue it down to the neck?
Author:  Chris Pile [ Fri Feb 22, 2013 5:16 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Quote:
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.
Author:  Irving [ Fri Feb 22, 2013 5:21 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Chris Pile wrote:
Quote:
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.


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.
Author:  StevenWheeler [ Fri Feb 22, 2013 7:50 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Irving wrote:
What would you do?


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.
Author:  theguitarwhisperer [ Sat Feb 23, 2013 1:10 am ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Irving wrote:
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?


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.
Author:  Stuart Gort [ Sat Feb 23, 2013 9:57 am ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Irving wrote:
Though I have sanded relief into the frets themselves.. but you can only do that a tiny bit.


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. :)
Author:  Irving [ Sat Feb 23, 2013 4:01 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
This is how my fretboard looks in the middle area on either side.

Image

Image
Author:  Chameleon [ Sat Feb 23, 2013 4:18 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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.
Author:  Irving [ Sat Feb 23, 2013 5:06 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Chameleon wrote:
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.


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.
Author:  theguitarwhisperer [ Sun Feb 24, 2013 1:53 am ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Irving wrote:

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.
Author:  JEguitars [ Sun Feb 24, 2013 11:29 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Honestly, that small gap wouldn't worry me, I would wait a week before re-radiusing.
Author:  Irving [ Thu Feb 28, 2013 3:18 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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.

Image
Image
Author:  nyazzip [ Thu Feb 28, 2013 3:49 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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
Author:  theguitarwhisperer [ Thu Feb 28, 2013 8:24 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
Irving wrote:
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.


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.
Author:  theguitarwhisperer [ Thu Feb 28, 2013 8:32 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
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.
Author:  nyazzip [ Thu Feb 28, 2013 8:54 pm ]
Post subject:  Re: Forward bow on half of fretboard. Straight on other half.
...and is that a douglas fir body...? sure looks like it to me
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