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Gap under fretboard
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Author:  guitarradTJ [ Fri Dec 30, 2016 2:28 pm ]
Post subject:  Gap under fretboard
Hello all, glued my first fretboard last night. I thought I'd clamped it up well enough..... Not so. Fretboard bowed and there's a gap between the neck and the fingerboard. How big of a deal is this? Fretboard isn't under tension when the guitar is strung up. Is this just an esthetic issue? Can I fill the gap later on? Gap is about half a millimeter in some areas.
First build issues....
Thanks for your help

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Author:  guitarradTJ [ Fri Dec 30, 2016 2:29 pm ]
Post subject:  Re: Gap under fretboard
Attachment:
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Attachment:
IMG_20161229_191032.jpg


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Author:  Rodger Knox [ Fri Dec 30, 2016 2:45 pm ]
Post subject:  Re: Gap under fretboard
The fretboard is part of the neck, and does carry some of the string load. I can see from the photo that the Titebond has not completely cured after the clamps came off, I would remove the fingerboard. It should come off pretty easily with a little heat. It's also a little unusual to glue the fretboard with the neck attached to the body, and there appears to be a gap at the body join. The top of the neck and the top of the guitar need to be flat and flush to glue the fretboard with the neck attached.
Author:  guitarradTJ [ Fri Dec 30, 2016 2:57 pm ]
Post subject:  Re: Gap under fretboard
Rodger Knox wrote:
The fretboard is part of the neck, and does carry some of the string load. I can see from the photo that the Titebond has not completely cured after the clamps came off, I would remove the fingerboard. It should come off pretty easily with a little heat. It's also a little unusual to glue the fretboard with the neck attached to the body, and there appears to be a gap at the body join. The top of the neck and the top of the guitar need to be flat and flush to glue the fretboard with the neck attached.

The glue is hard. I glued it last night at around 8pm and took the clamps off this morning at around 11. That should be plenty of time, right?
The gap wasn't there in the dry fit. I'm wondering if the fretboard warped over night with the humidity change?


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Author:  Joe Beaver [ Fri Dec 30, 2016 3:12 pm ]
Post subject:  Re: Gap under fretboard
I'm with Rodger. It needs to be redone.

What type of neck joint did you use?
Author:  Joe Beaver [ Fri Dec 30, 2016 3:15 pm ]
Post subject:  Re: Gap under fretboard
The moisture in the titebond does cause the fingerboard to try and bow.

Clamp force and location of clamps is the only defense.
Author:  guitarradTJ [ Fri Dec 30, 2016 3:26 pm ]
Post subject:  Re: Gap under fretboard
Joe Beaver wrote:
I'm with Rodger. It needs to be redone.

What type of neck joint did you use?

I used a Spanish heel joint. It's a classical

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Author:  kencierp [ Fri Dec 30, 2016 5:33 pm ]
Post subject:  Re: Gap under fretboard
The important issue is the condition of the fret side plane. If that is true or can be trued up I certainly would not take it apart. A small gap like that can be made invisible with lttle effort.
Author:  jshelton [ Fri Dec 30, 2016 5:51 pm ]
Post subject:  Re: Gap under fretboard
If the top on your classic is domed it's common practice to taper the bottom of the fingerboard from the 12th fret to the sound hole to assure a tight fit. If that wasn't done it could be part of your problem. Is the fingerboard cupping? Ebony, particularly if not well cured is very prone to cupping when exposed to moisture. Of course you can fill it and live with it but if it were my guitar I'd remove the fingerboard and start over.
Author:  Imbler [ Fri Dec 30, 2016 6:24 pm ]
Post subject:  Re: Gap under fretboard
On my first guitar, I was always reminding myself of "The cat in the hat" story where he is trying to clean out a small stain in the snow, and by the time he is finished he has spread the stain throughout the countryside!

I concur with Ken C. You will be truing the fretboard anyway with a trued beam with sandpaper on it. Then you will have a trued fretboard with just some gap to cosmetically fill.

On your -next- guitar, you need clamping around the heel area. Because of the negative neck angle on a classical there is always a "valley" right at the 12th fret where the negative neck angle meets the soundboard. It only takes a little pressure to close that gap, but that is where you don't have a clamp.

I know you think there wasn't a gap before gluing, but the gap you are left with is exactly what I would expect with the geometry of a classical neck if the 12th fret area isn't clamped. Even finger pressure closes that gap, so if you were holding the fretboard in that area while looking, the gap would not have appeared,
Mike
Author:  DennisK [ Fri Dec 30, 2016 7:27 pm ]
Post subject:  Re: Gap under fretboard
Peel it off and try again. Get at least one more clamp on there. Preferably two (one on the heel, one on the headblock).
Author:  guitarradTJ [ Fri Dec 30, 2016 7:55 pm ]
Post subject:  Re: Gap under fretboard
Thanks for all your input guys. Great advice. After further inspection the gap is only on the treble side, bass side is tight from the nut to the sound hole.
Treble side has the gap under the 12th fret. I should have had a clamp there like you guys suggested. I've decided to keep it as is and fill it later.
Build and learn!
Thanks again!!

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Author:  Joe Beaver [ Fri Dec 30, 2016 8:18 pm ]
Post subject:  Re: Gap under fretboard
Just a side note, but if you were to remove and reglue, or build another, I would use a lot more clamps. You have 8, 16 would be better.

I'd move the ones you have on the neck to the treble side and put 6 more on the bass side, two more at the heel, and maybe longer reach clamp with an arched caul on the neck extension and 2 more at the sound hole, if you can get all them to fit.

Another thing that will most likely will help is to put a heating blanket on the are, warm it to soften the glue and pull it in while hot with well thought out clamps. Just be sure that every where you heat it, be sure to clamp it while hot, or it is likely to make it worst.
Author:  Pmaj7 [ Fri Dec 30, 2016 11:23 pm ]
Post subject:  Re: Gap under fretboard
I don't know about others, but I always use a caul that puts the pressure on the edges of the Fret board.
Author:  Joe Beaver [ Fri Dec 30, 2016 11:39 pm ]
Post subject:  Re: Gap under fretboard
I agree Pat. On a classical I usually use 3 strips of wood as a caul. One running down the tremble side, one middle and one bass. Then I put all the clamps on them that will fit.
Author:  Mike OMelia [ Fri Dec 30, 2016 11:59 pm ]
Post subject:  Re: Gap under fretboard
This right here is a perfect example of why we use the Dry fit, fully clamped test. The dome on ur top is causing this. A mix of dome flattening and neck angle adjustment is needed. Warm the fretboard and spatula the thing off. Hope there is no glue in the joint.
Author:  Ruby50 [ Sat Dec 31, 2016 12:35 pm ]
Post subject:  Re: Gap under fretboard
Is it true that when you tension the truss rod to reduce relief, that the truss rod is pushing up on the fretboard about fret #5-6-7? I think this joint is structural with the tension on the rod.

Ed
Author:  DennisK [ Sat Dec 31, 2016 12:50 pm ]
Post subject:  Re: Gap under fretboard
Ruby50 wrote:
Is it true that when you tension the truss rod to reduce relief, that the truss rod is pushing up on the fretboard about fret #5-6-7? I think this joint is structural with the tension on the rod.

Ed

With a double acting rod, yes. Compression rod, no. And classicals don't typically have truss rods, so non-issue in this case.
Author:  Clay S. [ Sat Dec 31, 2016 4:45 pm ]
Post subject:  Re: Gap under fretboard
If that is the only noticeable flaw I would redo it. If it is one of many I would probably fill it and let it go. First guitar and flawless guitar seem to be mutually exclusive.
I usually use a 2 ft level as a clamping caul and a non water based glue (epoxy) that won't swell (and warp) the wood to glue fingerboards.
Author:  Mark Mc [ Sat Dec 31, 2016 7:23 pm ]
Post subject:  Re: Gap under fretboard
You can never have enough clamps, and the enges of the fingerboard are where you want plenty of pressure. I now clamp my fingerboard glue-ups with a rubber band - a bicycle inner tube cut longitudinally. I have the fingerboard held in position with three locating pins (just 1.5mm panel pins with the heads cut off) which are in holes drilled through the 1, 5 and 12 fret slots. The holes are invisible once the frets are in place later, and it doesn't really matter where they are located as long as they are off-centre to avoid the truss rod. The locating pins stop the fingerboard from sliding around on the wet glue. Then you just wind the elastic band around from one end to the other, stretching and pulling tight with each wrap, and overlapping the layers as you spiral along the neck. It is like bandaging up a sprained ankle. It provides very strong clamping pressure uniformly to the entire neck, and especially to the edges. A single clamp can hold the end down. You get some glue squeeze-out inside the wrap but Titebond doesn't bond to rubber so it is easy to unwrap it after 24 hours and then scrape or sand off the dried excess glue.

This method is easy to use when the neck is off the guitar. It would be harder to use for a spanish neck because you can't wrap the part beyond the body joint.
Author:  Mike OMelia [ Wed Jan 04, 2017 11:53 pm ]
Post subject:  Re: Gap under fretboard
I would never say I've never run into that problem. But I will say that once you have dry fit it, dome sanded, neck angle adjusted, etc, the thing should come together with minimal clamping and just a bit of falloff. Anything else, and you are forcing it into a new problem. Accept it. Fix it.
Author:  Ken Franklin [ Fri Jan 06, 2017 3:21 am ]
Post subject:  Re: Gap under fretboard
If you really want to know what you should do, run that pick over to the Delcamp forum and see what they think. A classical neck which has a negative neck angle is a lot different than what most builders here have to deal with on steel string guitars. The reason you have that gap is because of the negative neck angle. So you can do as J Shelton suggests and taper the fretboard extension. But some classical builders clamp hard at the neck join and level the extension later. You have no clamps at that spot which is why you have the gap. Sure you can shim it up but why not get some repair experience and take it off so yo can do it right. You'll be happier in the long run. It's one thing to notice a problem after the guitar is finished and another to let things slide when you know there is a problem before it's done.
Author:  Link Van Cleave [ Sat Jan 07, 2017 1:45 pm ]
Post subject:  Re: Gap under fretboard
Ken Franklin wrote:
It's one thing to notice a problem after the guitar is finished and another to let things slide when you know there is a problem before it's done.


Amen. I want to steal that Ken.

What Ken says.
You don't learn from your mistakes as well if you just move on. You could make them again or not understand fully why they happened. Re-do it, do it right and you will be the better for it and will have a better understanding of the whole deal.
L
Author:  George L [ Mon Jan 09, 2017 9:48 am ]
Post subject:  Re: Gap under fretboard
How would those of you advocating filling the gaps deal with the area I've highlighted below?

Attachment:
gap_pic copy.jpg
Author:  jshelton [ Mon Jan 09, 2017 10:38 am ]
Post subject:  Re: Gap under fretboard
Why stop there? It looks like the gap continues up the neck, that's why I asked if the fingerboard was cupped. What are you going to do about the glue showing in the gap? If you're going to fill it there are lots of products from black epoxy to standard wood fillers. None of which would be satisfactory in my opinion.
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