Crawls Backward (When Alarmed)

IconProjects, musings about guitar builds, guitar repairs, vintage tube amplifiers, old radios, travel, home renovation, and other stuff.

Bone Nut and Saddle for Kay K22 Guitar

Home stretch on the Kay Silvertone K22.

For whatever reason, I dislike having to thickness sand saddle blanks.  I don't hate it, I just don't like doing it.  It's probably because I have missed the mark a few...ok, several times and wound up with a too-thin saddle.  Then it's useless.

I was very cautious this time and routed the saddle slot so that a 3/32 of an inch blank would fit exactly and tightly into the slot.  Thus saving me from trying to sand it.

All I had to do was cut it to length and shape the ends a bit.  I also took some height off.  Obviously I'll be shaving it down during the set-up, but that's easy.

What I'll do now is make a nut, get it close to the final slot depths, and then finesse it and the saddle height until it's all set up.

I'm using the old nut as a pattern.  This one was actually a good shape and the slot were close to being spot-on - thanks to Jake's previous work.  However, it's plastic.

I hate plastic nuts and saddles.  So I'm making a new one out of unbleached bone.

First we lay out the string spacing.  Then I cut the initial guide slots with a razor saw.

I'm going to be a bit more scientific this go-round.  Usually I eyeball the slots and file them by trial and error.  But this time I'm taking a different approach.

I need to know the height of the first fret.  To measure this, I need a straightedge.  I used a triangular 'fret rocker' - a tool you put across frets and 'rock' to determine which one(s) are high or low.

With a feeler gauge, I find out that the height is .024 of an inch.  Maybe .025.  These frets are low indeed.

Now I take that height and add the estimated clearance for each string in its slot across the nut.

In other words, I'm adding the amount I need to clear the first fret by.  I'm playing it on the conservative side, so I start with .010 (inches here) for the high E, .011 for the B, etc., increasing each by .001.  The wound strings need more clearance.

In the foreground of the picture, you see a new Stew-Mac string slotting gizmo.  Pretty simple and clever, and pretty useful.

They call this thing the Safe-Slot Nut Guard.  What it does is let you clamp a feeler gauge across the fretboard.  In most cases, you'll probably stack feeler gauges to add up to the height you need.

The feeler gauges are then your 'stop.'  You file down until the file hits the gauge and your depth is (in theory) correct.

A lot of folks use feeler gauges, but this Safe-Slot (really?) thing eliminates your having to hold the gauge with one hand and file with the other.

In the picture above, the gauges are stacked up to .040 for the A string.  I just filed down till I hit the gauge.

I got a little gun-shy with my measurements, so I wound up adding a couple of thousandths to my original measurements just to make sure I didn't file too deep.

Then I strung it up, and fine-tuned the depths.  I would up doing just a couple more strokes of the file on each slot.  The clearance over the first fret is super low but doesn't buzz now.   This attention to the nut action makes an enormous difference in playability.

Then with the slots where I want them, I file off some of the height off the nut.  You can see the marks here that I'll file down to.  The wound strings will sit with about half of their diameter above the slot and the plain strings will just sit fully in their slots.  This way the strings won't bind in the slots when tuning or bending strings.

Here's the finished nut. 

Then I cut it to width, and polished it up to 12000 grit and then used compound.  I read Bryan Kimsey's pages recently and he was saying he doesn't polish guitar nuts up that far - he thinks they look like plastic.  Interesting.

I don't find that at all.  I think this looks like some kind of fine jewelry - maybe ivory.  Which is exactly the idea.

With the nut done, I can do the final shaping of the saddle and polish it the same way.

I curve the saddle to follow the radius of the fingerboard - in this case it's 12 inches.

I should have posted this picture higher up.

I slotted the bridge string holes with a Zona saw and then used a reamer to fit the bridge pins.  Just another detail that makes a difference in the finished guitar.

I also made a label about the truss rod and stuck it in the guitar.

None of these Kays had truss rods originally, so a future repair person's in for a surprise!

The finished guitar, freshly polished with Virtuoso Polish.

You can see I also put a tortoloid pickguard on it.  I hated that thick screwed-on pickguard that came on the guitar.  This one's a lot nicer.

It plays great now, and sounds pretty good.  I think the changes I made gave it a little more clarity and punch.  The neck is like a baseball (cricket?) bat!  It's at least an inch in depth at the nut.

I have some better pictures I'll post in the next installment.

 
 
 
 

Post a Comment 2 comments:

  • Unknown said...
    October 4, 2015 at 11:29 PM
    Do you happen to know the spacing and overall dimensions of this nut you cut (or original)?
  • Yr Fthfl Blggr said...
    October 7, 2015 at 8:01 PM
    Thanks for posting.

    I just measured it. It's 1.64 in wide, .145 in deep (parallel to the strings) and .349 in tall.

Post a Comment