fingerboard radius for archtop build

[Greg Martin]

I bought a .055 thick gold MOP block set to use on my 2nd archtop build. Im wondering if a 12" radius would cause inlaying problems ? Ive noticed if the pearl is thinner on the edges it reflects differently. Should I use a flatter fingerboard radius? is a flatter radius an advantage or a disadvantage for and acoustic archtop ? Also am I correct that the inlay cavity should be routed before the finger board radius is sanded in?

[Barry Daniels]

A lot depends on how big the inlays will be. If you are doing typical arch top block inlays that extend nearly across the entire fretboard then you will be getting pretty thin on the edges. We used to have the blocks divided into two halves and we tilted each side a bit to prevent thin edges. We routed the inlay recesses before radiusing the fretboard to keep things simpler.

[Michael Lewis]

There are a lot of ways to "skin the cat". Some ways work better for 'one off' and some are better for production. I have usually routed the recesses after the board was radiused, but either way can work. The final result is the proof of the process. My reasoning for routing afterward is the surface is established and then you can figure how deep to cut the recesses. I think it much more difficult to figure that out for a flat board that will be radiused after the rout. Take your time and think it through before cutting anything.

[Greg Martin]

so are you saying to rout a curved bottom cavity ? I dont suppose soaking the shell in anything will help slight 12 " radius gluing/bending ???

[Chris Richards]

I think that there are a few "fixed" dimensions.... If you start by planing/sanding the fretboard to thickness but don't radius it. then you can route the inlay recesses to 0.055" and then see what radius you can get away with. Fingerboard radius is quite a personal choice and there's nothing "set in stone" as to what it should be, although anything around 12" is the norm.

[Dave Stewart]

I've done block inlays using .055" on 12" radius without problems.
Regardless, draw it out (in cad if you can, large scale if not) to see what you're dealing with.

[Michael Lewis]

Rout the recesses for the inlays in the radiused board and fit the pieces into them. You will immediately see how they fit in relation to the surface of the board. Sometimes you have to fill a bit under the inlay piece to get it flush in it's center, and sometimes you have to remove a bit more material. The outer ends will be above the surface of the board slightly but NOT by as much as the piece is thick. There has to be some inlay remaining after it is sanded level with a block.

Assuming your radius is constant, make the center of your inlay piece flush with the surface of the board. This will maximize the thickness of the ends of the piece when leveled. You will not bend MOP, it will crack and break unless extremely thin.

[Greg Martin]

No magic just common sense. Im goin in !

[Greg Martin]

I have a fb that was going to be used on another project and as mentioned its 12' radius'd and slotted already,now instead of dots we want block inlays.maybe I can do a spit block inlay and build it around the radius,or I may just make a new fb.