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Martin Refret

6/23/2014

This article originally appeared in Guitarmaker Magazine.  The trade journal of the Association of Stringed Instrument Artisans.

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1. Martin Custom Shop Martin 0-42.  The owner of this guitar has a bone to pick with his new guitar.  Some of the frets are a little too low for comfort and there is some fret buzz.  Adjusting the truss rod won’t get rid of the fret buzz, it just moves the buzz around.  There isn’t much fret height to work with so the solution here is a refret. 2. Notched Straightedge.  I’m using a notched straightedge to check the fretboard as I adjust the truss rod.  This neck is pretty straight from the 4th to last fret, but there’s a low spot starting at the 3rd fret that gradually gets worse toward the nut.
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3. Adjusting the Truss Rod.  Someone at the factory must have noticed the drop off at the nut end of the fretboard because there was an attempt to fix the problem by sanding the frets to give the neck more relief. 4. Removing the Frets.  I’m safely removing the frets with flush ground end nippers and a soldering gun with the tip cut.  The heat prevents the fretboard from chipping while the end nippers force the fret upward while pressing down on the fretboard at the same time.
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5. Fret Pullers.  My end nippers have a very shallow inner bevel and a v-shaped opening.  This more slowly forces the frets out of the fret slot so the tool is much less likely to chip the fretboard than standard fret pullers. 6. Sanding the Fretboard straight under simulated string tension in the Erlewine neck jig.  I’m sanding the fretboard with 80 grit pressure sensitive adhesive (PSA) sandpaper attached to a long aluminum radiused sanding beam.  This quickly and accurately sands the fretboard straight and to an even 16” radius.  Next, I’ll use 120 grit PSA.
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7. Hand Sanding with 220 Grit sandpaper wrapped around a belt-sander cleaning eraser gets rid of the 120 marks.  Next I’ll sand the board with 400 grit PSA on the radiused sanding beam to dial in the fretboard profile followed up by 600 grit wrapped around the eraser. 8. Preparing the Fret Slots.  I lightly beveled the top of the fret slots to prevent chipping with a file that has a triangular cross-section.  Now, I’m using a small saw that I made from a Japanese dovetailing saw with an .018” kerf to break up most of the glue that’s in the fret slot.
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9. An Exacto Knife blade with a snapped off tip cleans the majority of the glue out of the fret slot.  I’m pulling the back of the blade toward the binding.  Then I’ll pry the glue up and out of the fret slot.  I’ll repeat the saw and exacto knife routine with a similar saw that has a .022” kerf. 10. Preparing the Fretwire.  I cut each fret to rough length then file away the tang at the ends of the frets with the LMI fret tang filer.  This will allow the fret crown to extend over the binding on the sides of the fretboard.
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11. Frets Ready for installation.  The customer has opted for Jescar stainless steel .095” x .047” fretwire.  I pre-bent the fretwire to a 16” radius to match the fretboard prior to cutting each fret to rough length. 12. Installing the Frets over the body and neck heel with a deadblow mallet.  The Taylor fret buck absorbs the shock of the mallet which allows the frets to more accurately seat.  The guitar is still in the neck jig.
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13. Jaws is a fret pressing tool that saves lots of time.  I’ve adjusted the jaws for a thinner neck so they can’t close all the way to the locking position.  Now I’m pressing the frets home relying only on my hand pressure (photo 20). 14. Gluing the Frets with thin super glue.  I oiled the fretboard with a light coat of stew mac’s fretboard finishing oil.  The oil both prevents the thin super glue from staining lighter colored fretboards and makes it easier to clean up any squeeze out.
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15. Clean Up the excess glue with a small square of paper towel lightly dampened with acetoneand immediately clamp down the fret with the jaws tool set to lock in place.  I’ll put a drop of accelerator on the fretboard next to the fret with an eye dropper. 16. The Drill Dress does a great job of clamping the upper frets while the glue hardens.  I’ve modified my Erlewine neck jig to both hold and reinforce the guitar while pressing the upper frets.
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17. Neck Support.  The cork-lined neck support caul is pressed firmly against the back of the neck by the jig’s neck support rods.  Two small c-clamps with small V shaped notches filed into the jaws lock the support rods in place so they won’t move under the pressure of the drill press. 18. Neck Block Support is provided by a cork-lined caul held in place by a spare height adjustable swivel top leveler screwed into a round nut.  Veritas sells a similar round nut for use with their bed bolts and workbench vise installation.
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19. The Taylor Fretbuck supports the top beneath the fretboard as I glue and clamp the frets over the body.  I apply the accelerator with an eye dropper or small straw from an accelerator pump bottle. 20. Flush Cut End Nippers trim the fret crown nearly flush with the binding with the cutters running parallel with the neck binding.  Holding the flush-ground end-nippers in this orientation to the fretboard gives me cleaner fret ends.  As I cut the fret ends over the body, I will use a small metal guard as a spacer to protect the side of the fretboard while using the cutter vertically.
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21. Beveling the Fret Ends.  I’ve hand-filed a bevel into the fret ends starting with a course file, then a fine single-cut file.  Now I’m using 400 grit PSA on a short aluminum sanding bar.  With the files and the short bar I’m focused primarily on the interface of the bottom of the fret end with the binding.  The fret ends have a somewhat steep bevel which I will fine-tune later. 22. Simulating String Tension allows for more accurate fretwork.  The special turn-buckle pushes up on the end of the headstock while the strap pulls down on headstock by the nut.  This is what simulates string tension.  Two dial indicators tell me when the neck is in the exact position it was in prior to removing the strings.
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23. Leveling Frets.  A long sanding beam with 400 grit PSA levels the stainless steel frets after just a couple of minutes of sanding.  The long radiused sanding beam that I used to sand the freeboard also works for leveling frets. 24. Beveling the Fret Ends continued.  Fine tuning the bevel at the fret ends with the long bar will ensure that the functional real-estate of the fret-crowns will evenly terminate going up the neck.
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25. A Crowning File is my tool of choice for spot crowning and dressing the fret ends.  I prefer the 300 grit offset diamond crowning file for these steps. 26. Sanding the Frets.  I’m using some P600B grit sandpaper wrapped around a narrow strip of thick photo-paper to sand the crowing file marks form the fret ends.  I’m hitting every fret end on the side of the fretboard with each stroke.
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27. More Sanding.  With the 600 grit sandpaper wrapped around my middle finger, I’m sanding the frets to get rid of the spot crowning marks.  I’ll repeat these two steps with 1000 grit sandpaper then sand only the fret crowns (not the fret ends) with 2000 grit sandpaper. 28. A Couple of Passes with 2000 grit sandpaper wrapped around the short sanding bar dials in the fret crowns and eliminates any stray 400 grit marks.  I’m sanding parallel to the frets, not along the length of the neck with the fretboard’s wood grain.
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29. Polish.  I’m giving the frets their final polish with the buffing arbor.  The course wheel is charged with red menzerna compound and the fine wheel uses the ivory colored compound.  This makes the stainless steel frets very smooth and shiny. 30. Polished Frets and a smooth fretboard are a joy to play on.  These stainless frets will keep their polish for a long time.
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31. Rounded Fret Ends are easy on the hands. 32. The Binding looks great and has not been disturbed.
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33. All Done.  When this guitar came into the shop it sounded great, but after a refret it’s also a great playing guitar.