Randy Roberts' photo-essay on making semi-hemispherical fret ends for bound fretboards [Pictures] - created 01-20-2012
Roberts, Randy - 01/20/2012.22:13:05
May your life's music always come from your heart.
After receiving advice in a previous thread I decided to try my hand at rounded fret ends for a bound fretboard I was making. I decided to try to make a jig to help get better quality control over the end result than I could possibly have doing it just by hand.
It ended up working really well, and I think the one jig should be universally usable over a wide range of scale lengths and fretboard widths. Scale length shouldnt matter since the progressive change in length progressing down the fretboard is an incremental proportional change. Different fretboard widths are easily dealt with by varying the thickness of a shim that guides the final filing down of the fret lengths.
I started by making a frame wading pool, or dam to make a mold of the fretboard with Bondo.
I filled the frame with Bondo and then pressed a Saran wrap covered fretboard into it while it hardened.
This gave me a negative of the fretboard that accurately showed where the fret slots were.
I then took this Bondo negative of the fretboard, laid Saran wrap over it and pressed a second Bondo filled frame into it to create a top and bottom mold. This positive mold had the fret slots transferred into it by the negative mold.
I cut the fret slots marked in the Bondo, using a kerf that would allow placing the frets into the slots but not holding the frets tightly so the fret could slide back in forth in the slot. I cut a piece of rubber to go between the molds to hold the frets securely when clamped, installed 4 register pins, and drilled holes for screws and wing nuts to clamp everything together.
I reinforced the molds with scrap ¾ inch plywood and then sanded the edges down to the same taper as the fretboard I want, but made it narrower by about a quarter inch than the narrowest fretboard I could conceive of needing to use it for.
So here is how I used the jig.
Laying the fret wire in the slot with the far end butted up to a straight face behind the jig made it easy to cut the frets to rough length.
The jig was then closed with the rubber between the top and bottom holding the frets securely. I just ran the jig down my sanding board to square off the ends on one side of the frets. (I use a 5 foot long by 6 inch wide piece of granite that I got out of a dumpster at a granite counter top company. I find that I am constantly reaching for this to sand lots of things. Its my precision slow-motion belt sander and is great for scarf joints, fretboards tops and backs of pegheads, etc.)
I rounded the ends by first hogging off with a 300grit diamond crowning file from Stew Mac. Only takes 5-6 swipes on each side.
Then I refined the rounded end by taking 2-3 swipes per side arcing the fret as it swept across the sandpaper. I did this at three different tilts of the fret to create a hemisphere. This was on 600 grit with a soft but firm backing. (I cant hold on to the stupid frets worth beans so I made the little fret holder and it worked great. The fret cant rotate in my fingers because its tang is in the slot cut in the holder.)
Then I polished the end with Micro Mesh 3200 grit using a shoe shine technique.
With the frets back in the jig, I aligned the finished ends with a true straight face like before, and filed down the unfinished ends to get the final length for the frets. This is where the jig gets universal. Because the jig is narrower than the fretboard, I made wood shims to lay above and below the row of frets. I then filed down the fret ends by sliding a file along the shims. By loosening the wing nuts at both ends of the jig I could slide out the first and last fret and check them against the fretboard. If the frets need to be a little shorter yet, all I have to do is run the shims through the thickness sander to take off a few thousands and then file a little more off guided by the new thickness of the shims until I have exactly what I want for fret length.
A last check to make sure no fret stands proud
I finish sanded the fretboard up through all the micromesh grits which leaves a glasslike surface.
To press the frets in accurately I just made a little alignment jig that butts up to the side of the fretboard, positioned the fret against the 0.010 shim on the alignment jig, then pressed the fret home. After seating all the frets I switched to a slightly tighter radius in the fret press caul, touched a drop of CA to the end of the fret and pressed the end of the fret down.
And then, in looking at this picture realized this was for a 12 fret to the neck OM and I had used that fingerboard to make the jig. It only has 20 frets .AAARGH! Oh well not that hard to make another (longer) one.
Oh, and you don't even have to make a bunch of holes in a block of wood to hold the frets for you.... the jig holds them in order for you
Very neat! You have devised an excellent way to maintain the integrity of a decorated fretboard, divorcing it from the fret end rounding process.
That sure beats doing them one at a time (as I do) which is cruel and unusual punishment.
Great work& great pics Randy....thanks for posting!
Excellent tutorial. Thanks for posting it. It is something I will try in the near future.
That's just brilliant, Randy! Very well thought-out, and very repeatable.
Having only attempted semi-hemi fret ends once (and poorly), I don't have much of a grasp on the finishing necessary after the initial rough shaping of the ends (post #8). I wonder if there would be a way to do the refined finishing without removing the frets from the holder. Would it be possible to do the steps shown in posts #9 and #10 with a specially-shaped sanding stick/caul, or a dremel buffing wheel? That way, everything stays put, you keep your repeatability, and you can check with a straight-edge to make sure you haven't buffed one too short.
And yes, that is a gorgeous fretboard! Is that just polished wood, or did you do a seal with CA?
Great method Randy. Thanks for sharing.
Nice pieces of AbLam there by the way ;-)
Someday maybe my process will be so rigorous. :P
Thanks, Hopefully it will make things a little easier if you want to do frets this way.
That was a big part of my thinking. I'm the kind of guy that meticulously scrapes a top and then drops a chisel on it. This way I can't damage the fretboard very much.(with this step anyway).
I think that it would be harder to try to do the sanding part in the jig than to just lift them out, and it's a little crouded down at the far end where the frets are close together. This only takes about a minute a fret end.
The shiny fretboard in #13 is just ebony that I sanded with Micro Mesh, no CA. I usually seal the fretboard with CA before final sanding, and I wish I had this one so the ebony dust/CA fill on the inlay didn't stand out so visibly. If I had it would have been invisible. I forgot until it was too late.
That's the scrap strips that Chuck Erickson was unloading for like $2.00 a ton at GAL this summer. I've been trying to figure out stuff to do with it.