Trimming a wide fingerboard blank

[sixesandsevens]

Hi all,

I'm working on a kit build and wanted to "upgrade" to a slightly wider nut and a fretboard with no inlays. I got a slotted ebony blank, but it's not trimmed to the final dimensions. I have a few questions before I get started.

Note that I thought to check and the kit's neck shape is rough shaped and leaves enough that I can fit a 1.75" nut.

- For a pre-slotted fingerboard, I assume it's critical to mark the centerline and take off a symmetrical amount from each side. This will make sure the fret slots stay perpendicular to the strings. Is that right?

- I don't currently have a bandsaw, so my thinking was that gluing it up first and then planing it or sanding it to meet the neck shape from the kit would be kind of like "guard rails". Is there a better way I should be getting the fretboard to the right dimensions?

- Because this blank supports a lot more frets than I need, I'm going to do a curve at the end of the fretboard that overhangs the sound hole slightly. I realized as I'm typing this I'll probably need to buy at least one or two extra frets to trim in for the overhang.

Are there any gotchas to doing this that I'm not considering?

[BlindBo]

You can do this on a table saw using a tapering jig. You are correct, everything needs to be laid out from the center line.
Determine what width you want at the 12th fret (frequently 2 1/4”) and lay out your trim lines. Fretboards are expensive, so, I like to cut mine a hair proud on each side so the I can “shoot” the edges straight. Check YouTube for a video on making fretboards and “shooting boards”. (And please don’t ask me how I know replacement fretboards are expensive!😖) On my table saw I have to reverse the fence to the other side of the blade to make the second side cut.
Again, I’m betting there are videos out there that explain this more clearly than I am!😂
My best advice is measure more than twice to make sure you have the layout where you want it before cutting.
Good luck!

[Stray Feathers]

I'm not sure why you would run the fretboard out over the soundhole, except as an intentional design element? Can you not use the original fretboard as a template for length? That also saves you the worry of making sure you have matched the existing and extra frets exactly. As BlindBo says, "And please don't ask me how I know . . ." Bruce W.

[BlindBo]

Sixes, I forgot to mention something. I’m not sure what kit you are building, but, most of my early kits had a lot of excess wood on the rough cut neck as received with the kit. My first build I didn’t realize it and ended up with a really chunky neck. These days I do a fair amount rasping to get the neck profile somewhere between a Martin and a Gibson profile. You may want to do some of your shaping before attaching the fretboard.
If you don’t have a table saw, you can taper your fretboard using a sharp hand plane, shoot the fretboard sides close to the neck dimensions and then finish file/sand the neck and fretboard together to give you a really nice neck/fretboard joint.
Hope this helps.

[sixesandsevens]

I'm not sure why you would run the fretboard out over the soundhole, except as an intentional design element? Can you not use the original fretboard as a template for length? That also saves you the worry of making sure you have matched the existing and extra frets exactly. As BlindBo says, "And please don't ask me how I know . . ." Bruce W.

You got it right on the first try: it's a design element I've liked on other instruments and I thought it would be an easy element for the first guitar.

@BlindBo - Thanks for the advice!