Wednesday, 19 June 2013

Baritone Guitar Build Part 2 - The fret board

I opted for using ebony for the fretboard and nickel silver frets. I also wanted to inlay the board with some nice red abalone I had. First of all I chose a nice theme for the inlay and this was an Arabesque pattern I saw a few years ago.
Using a jewellers saw and some fine blades along with a simple piece of softwood with a slot and a hole I broke several blades but ended up with a nice set of inlays.

Then I run the ebony through the jointer to flatten one side and then ran it through the thicknesser to get it around 7mm (9/32") thick.
The next task was to put the radius onto the board. I used a 12" radius aluminium fret levelling beam from StewMac with some self adhesive sand paper of 80 grit to do the initial shaping.

Essentially the aluminium beam has a concave radius of 12" machined into one face. You stick the sandpaper onto this face.
Then with the board fixed to the bench with some double-sided tape you transfer the concave radius to the board by moving the beam back and forth sanding a convex radius onto the board.

I then cut the board edges slightly larger than finished size on the band saw.

Next I used a small router to rout a slot or dado at one end of the board for the nut. This will also be used as a datum for all the fret slots.

To cut the fret slots I used a shop made fret slotting mitre box as a guide for my fret saw.
I usually mark out the frets using a chart in pencil. Then using my digital calipers I index the board to the right position dictated by a spreadsheet. Then I cut the first slot. The pencil marks are only used as a visual guide to make sure I'm not way off course.
Indexing the board on to the next position, finally tuning the position of the slot with the calipers I cut the next slot. I always use the measurement from the nut to fret rather than fret to fret to avoid cumulative error.

After cutting 24 fret slots using this method I ended up with this:

Slotted board with the inlay roughly positioned
The next thing to do was to scribe around each inlay piece in turn and use a Dremel with a very fine spiral cutter to rout out the recess for the inlays. This was very time consuming and demanded good eyesight. I use a high powered binocular OptiVisor from Stewmac to accomplish this.
View showing routed recess

Inlay piece in the recess

More inlay pieces waiting for me
to rout their respective pockets
Each of the inlays were glued into the board using black CA glue. When dry I used the levelling beam again, with various different grits, to flush the abalone to the same level as the ebony. The CA glue is a medium viscosity and fills any minor routing imperfections.

Board during final sanding
Finished board
Finished thickness of the board is around 6mm (1/4")
Next time I'll show the neck construction, fretboard installation and fretting process.

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