Fretboard, re-glue

[OldDave]

I am ready to re-glue my fretboard. Posted this to my other thread about "neck gouge" but no response, so thought I would try a new thread. Fixed gouge with mahogany inlay, took a while to figure that out. Now with no fretboard the neck is dead flat with the truss rod nut backed almost completely off. The board itself with new frets has .125+ back bow. My concern is if I attach it to the flat neck it will induce some back bow, and I will have no way to adjust it out. Would it be possible to create some relief with a clamp as I'm gluing.

[bisco1]

John Hall of Blues Creek Guitars has a video showing him clamping the fretted fingerboard to his bench while shimming each end of the board with piece of wood and leaving it clamped up over night to take the back bow out of the board. You can find it on Youtube. Also, I know that many believe the glue you use to glue the board on has an effect on how much back bow is imposed by gluing. I personally prefer HHG or fish glue for this job. Good luck, Bill

[charles Tauber]

Originally Posted by OldDave

The board itself with new frets has .125+ back bow. My concern is if I attach it to the flat neck it will induce some back bow, and I will have no way to adjust it out. Would it be possible to create some relief with a clamp as I'm gluing.

If I'm reading you correctly, you have installed the frets in the fingerboard prior to attaching the fingerboard to the neck. That is a common approach. Another common approach, one that I prefer, is to fret after gluing and truing the fingerboard.

Try this. Place your fretted fingerboard on a flat surface, concave side down. Now press on the middle of your fingerboard. Observe how much force is required to press the fingerboard flat, removing the "back bow". What you'll learn from the exercise is that the fingerboard is pretty flexible and it doesn't take much force to flatten it. (If you want, perform a similar action on the neck observing how much force is required to deflect it. You'll discover that the neck is much stiffer than the fingerboard.)

When glued and clamped flat to the much-stiffer neck, the neck/fingerboard assembly will be flat after the glue dries, unless your neck is very flexible. When strung, you'll have the string tension to pull on the neck. In many cases, that tension will cause the neck to bow.

As an aside, when levelling a fingerboard already glued to a neck, I plane/sand a slight back bow into the fingerboard, then fret. With the string tension, it becomes flat or with a light bow.

[OldDave]

Bisco, and Mr Tauber, thanks so much for the replies. After much internet study, and several dry runs I think I'm going to be ok. Tied the board down with the rubber bands nurses use when you have blood drawn [ I have several now ]. Checked with my straight edge, about .004 to.005 relief at 7th 8th fret. Would like to use hhg, but being new to this and severely fumbled fingered, I'm going to use titebond and hope that gives me enough time. Wish me luck as it's going on today. The worst that can happen is I get to take it off and start again.