New Fretboad Doesn't Sit Flat on Neck

[bails]

Just bought a '78 MusicMan StingRay with no fretboard, but with a loose rosewood blank which the seller never got around to attaching. The problem is the neck surface is slightly curved so the fretboard won't sit flat. I'm hesitant to flatten the neck in case I expose the truss rod cavity, so I thought I could instead have a go at rounding the underside of the new fretboard ala early 60s Fender necks.

Is this achievable by an amateur who's good with his hands, but has never built a guitar? Do I do this simply by resting sandpaper on the neck and rubbing the blank against it?

Could I cut fret slots in the blank or this a job only for pros (I do have an Exacto saw, but would need to build a mitre box)? I'm happy to try a fretless as I don't have a lot of money for luthier work presently, but I'd prefer a fretted neck if it was achievable.

[ken_j]

If I understand you right the neck without a fretboard is curved in the same way as the crown radius of the fretboard. If so put some self-adhesive sand paper on the neck and sand the bottom of the fretboard to match. This will be a difficult task. I would suggest building a jig to fixture the pieces and control the movment. Placement of the frets is an exact science. I have the calculations needed to do so but also the tooling which makes it much easier.

[jingle_jangle]

If I was presented with this problem, I'd probably take the other tack--sanding or planing the neck area flat, unless there was a noticeable crown on the neck top surface (more than 1/16"). If the truss rod is exposed (don't think this likely with a 1/16" or less crown on top), I'd simply rout the groove a bit deeper, but only if the rod was standing proud and prevented the board from seating properly.

This is obviously set up for a curved veneer board, and they are CNC-made. You can sand the bottom concavity into the board, but it will take forever and will probably be inaccurate.

[bails]

I've examined the neck and it appears than it was originally one-piece maple, that has simply been sanded back to the fret slot depth. This accounts for the radius, and by comparison to my other StingRay, I can see hardly any meat has actually been removed from the neck. As a result, I feel more confident to sand* it flat, and remove some wood before I glue on the new fretboard. I've also decided to buy a pre-slotted rosewood fretboard because, for only $35, it's worth getting it right.

*Note: I am actually considering securing the neck to a jig and routing it flat. Is that a ridiculous idea, or an appropriate way to ensure a flat surface?

[ken_j]

*Note: I am actually considering securing the neck to a jig and routing it flat. Is that a ridiculous idea, or an appropriate way to ensure a flat surface?

That is how I would do it unless you have a wood mill. The other option is to true up the neck as is and cut new fret slots in the maple. How about a few pics?

[bails]

The threaded truss rod end is already exposed within the area of the first fret, and the truss rod anchor is visible near where fret 21 should be. These parts must have been covered by maple only as thin as the depth of fret tang!
Definitely needs a new board to cover these.

Pictures to follow...

[bails]

Black side dot markers sanded through and truss rod anchor visible at bridge end, truss-rod end exposed into first fret area, fret slots faintly visible at various points on neck.

[jingle_jangle]

Depending upon what type of fretboard wood you want, a thicker maple cap with the proper crown radius will cover it, or a maple cap to replace the depth sanded away, then a rosewood 'board over that. My way of doing it would use a thickness sander to bring the maple down to proper dimension, cut the fret slots, and crown the board using a fretboard belt sander with radiusing attachment to put the crown on. I'd cut and taper the board's width to about a millimeter wider than the neck all the way from nut to body end. I'd glue it in place and clamp it. Then I'd carefully hand sand the width to match, and add a bit of radius to it to blend into the neck, and break the top edges very slightly for comfort. I'd press in the frets and nip and file the ends, then round off the eds and flatten and re-crown the frets. Polishing is optional, but a nice touch.

[bails]

Just found out that MusicMan used curved bottomed rosewood fretboards (ala post '63 Fenders), and was wondering how to replicate this.

I thought I might actually route the neck flat (for a slab board), except leave the last 10mm raised with a convex curved. I could then cut a concave curve into the last 10mm of the bottom of the slab board so it would appear like a curved bottomed fretboard, with the hassle of curving the whole board. Is this a decent plan, or destined to fail?

What was the purpose of curved bottomed fretboards that Fender introduced in 1963, and what's the professional way to replacing one?