Thursday, December 31, 2009


Time to fret!

I have to do a couple of things to prepare the fretboard for the frets.  First is to make sure that the fretboard is perfectly flat.  It was when I made it, but in gluing it onto the neck it's possible that a little hump has been introduced at the 14th fret neck/body joint.  If the body and neck aren't perfectly in line with each other, then when the fretboard extension is glued to the body the clamping force will push it down a skosh.  A little sanding will remove this skosh.

Then I have to radius the fretboard across the width.  Different makers use different radii, but I like a 16' radius, which is what Martin uses.  For me Martin is the standard and any deviation everything works off of that; so until I have enough experience to know what effect a deviation from the standard is going to have, I'm sticking with the standard.

I use a special sanding block with the 16' radius; yo ucan see here what a small amount of curve we're talking about.  I draw a centerline down the fretboard, and start sanding with 100 grit paper. 

When the centerline disappears all the way down the length I know the fretboard has been fully radiused.  I then switch to 150 grit paper and finish with 220, which leave a nice smooth finish on the fretboard.

Fret wire comes in different sizes and different widths.  There are two main components to a fret: the fret itself, which sits above the fretboard, and the tang, which fits into the slots that were sawn into the fretboard.  A cross section of a fret would look like a T with the top rounded over.  Along the length of the tang are barbs that grab hold of the sides of the fret slot and hold the fret in.  Fretwire from LMI comes in a coil, which is convenient since the fretboard is domed.  Other suppliers send the wire in straight sections--it's probably easier to mail like this--but then the curve has to be introduced.  If not, the wire wants to spring back to it's original straight shape after being hammered in, and that's not a good thing.

I cut the fretwire for each fret first.  Because the fretboard gets wider toward the body each piece is a different lenght, so I drilled some holes in a stick and numbered them to keep track.

The fret slots don't extend into the fretboard binding; this keeps the tang ends from being visible, but means that the tang needs to be removed where it goes over the binding.  I have a special tool that nips the tang off the end, and then remove any burrs left with a file.


Every guitar is eventually going to need to have the frets replaced, and the danger in removing frets is that the barbs can chip the fretboard right at the slot.  To help prevent this in the future I use a small triangular file to bevel the top of each slot.

Loose frets are never good, so as an added precaution I put a little Titebond wood glue on the tang before hammering it in.  I use Titebond rather than epoxy or superglue because it loosens with some heat, so in removing the fret in the future it can be heated with a soldering iron before removing the fret.  Here's the first fret hammered in, after I've wiped the glue squeeze-out with a damp paper towel.

Just to be sure the frets are seated properly I'll stop every once in a while and squeeze them in my vice.

The fretboard extension is a problem since hammering over this unsupported area can crack the top.  First I widen the slots using a small piece of fretwire that's been bent 90 degrees.  By running the tang through the slots the barbs scrape away some of the wood from the slots.  Then I use more glue than in the other fret slots, lightly tap the fret into the slot just enough to hold it in place, and put the 16' radius block on top of the fret and clamp it down, using a caul inside the body like when I glued the fretboard on.

I do this for frets 16-20.  (I can hammer the 14th and 15th fret because the heel block provided the mass needed to protect the top.)

Once all the frets are installed I check to make sure they are all well-seated.  I then use some fret nippers to clip the ends as close to the fretboard as possible, and a file to finish the job so they are flush.

Oh, hey, I remembered I had a special fret file that I should have used.  The edges are rounded so I don't have to worry about damaging the wood when I file the frets.  I grab it and level the frets so they are even with each other.

This is an important step, because if a fret is higher than another one, then when a string is fretted just above the high one the vibrating string will hit the high fret.  At best this will dampen the string, affecting both it's tone as well as its volume; but usually what will happen is an annoying buzzing that will drive anyone within listening distance to run from the room.

I have a piece of metal that has sides of different length.  If when I place it across three frets it doesn't move, the three frets are even with each other, but if there is any rocking movement then I know that the middle fret is higher.

The different length sides are because the frets get progressively closer as you move down the fretboard (toward the body) and pretty soon I'm spanning four frets with the long side, and it's impossible to then identify the offending fret.  I used to use my engineers square for this but it didn't work well for the last few frets.  This little tool was worth the money.

OK, so now all the frets are level, but now instead of a nice round crown, the frets have a flat surface, so now I have to re-crown the frets.

This is done with another special tool with a concave filing surface.

Even though the sides of the file won't reach the fretboard I use a piece of thin metal with a slot for the fret to protect the fretboard in case I slip or something.

After the frets are crowned, the ends get beveled.

Then I remove the sharp burr from the ends and round each end so that the player's hand moves smoothly up and down the neck and doesn't encounter any sharp edges.  This file is smooth on all but the two sides so I can use it without protecting the fretboard.

That's it for now.  One of the last things I'll do before delivering the guitar is to sand the frets to remove the file marks, and then polish them to a nice shine.  For now, it's time to prep the guitar for applying finish.

Monday, December 28, 2009

Shaping the Neck

With the fretboard glued on, it's time to shape the neck.  I start by bandsawing the excess neck wood close to the fretboard, and then use a rasp and scraper to get the sides of the neck even with the fretboard.

Before shaping the neck I need to finish shaping the heel.  I rough shaped it back when I was fitting the neck to the body and working on the neck angle, but I need to finish it now.  This is chisel, rasp and sandpaper work.


Now on to the rest of the neck.  There are a number of different methods of shaping the neck; this is the way that I was taught.

At the first and ninth frets I measure both the thickness of the neck and the width of the neck.  Remember, the neck gets both thicker and wider as you go toward the body, and I want a nice, round neck all the way down.

I transfer these measurements to a piece of paper, drawing a rectangle with the height representing the neck thickness and the width representing the neck width.    Then, using a compass I draw a half circle that touches both lines.  This represents the back of the neck, with the bottom line representing the fretboard.  So what I have drawn is the neck in cross section.  The rectangle is the neck as it currently is shaped, and the half circle is the neck as I want it to be shaped.

I add a centerline, then draw a line tangent to the circle at a 45 degree angle from the centerline.  I measure the distance from the centerline to where the tangent crosses the line representing the back of the neck, and also the distance from the fretboard to where the tangent crosses the side of the neck.

I do the same for the ninth fret:

I transfer these marks to both sides of the neck and draw a line connecting the marks at the first fret with those at the ninth.  The material between these marks is not neck material and needs to be removed.

I hog off material using a spokeshave, then take it closer to the lines using a rasp (which you can partly see in the left of the picture.)

So I've taken a rectangular piece of wood with two corners at the back of the neck and removed the corners, creating two facets with two corners for each facet.  I go back to the diagram and use the same procedure to removed these corners, transferring measurements to the neck, connecting lines, and using the rasp to creating removed material that is not part of the neck.

I put the rasp away and use a scraper to removed these corners, then 100 grit sandpaper to smooth everything out and get to the final shape.  At this point it's all looks and feel.  I look at the neck to see obvious high points, and run my finger along the neck to feel for smaller high points.

As the neck approaches its final shape, I pick it up often and hold it in playing position, seeing how it feels at various points but paying close attention to how it feels at the first fret--open position, where most of the playing is done--and down at the heel where the cutaway is.

After making some final adjustments at the heel area and also where the neck transitions to the headstock, I'm satisfied, and we've got something that looks a lot like a guitar!  Here are some pics:



Next up is doming the fretboard and installing the frets.  We're getting close!

Thursday, December 24, 2009

I Ain't Braggin' But...

OK, so irrespective of what is actually in the box--although it's pretty sweet--I think I deserve major props for wrapping a triangle and it not looking like crap.

 It ain't easy.  And I'm a guy and all.  That's all I'm saying.

Tuesday, December 22, 2009

Gluing the Fretboard

Before glue gets sticky, it's slippery.  That's the challenge in gluing the fretboard to the neck.  The 14th fret must stay right on the neck/body joint, and the centerline of the neck must be perfectly aligned with the centerline of the neck.

I put the fretboard on the neck in the correct position, using a straight-edge to align the centerlines, then use a couple of spring clamps to hold it in place.

Next I drill a hole in the first fret slot and two at the 11th fret slot through the fretboard and just slightly into the neck, all off center to avoid the truss rod.  These holes are small enough to be covered by the frets.  Then I hammer a small nail through each hole and into the neck, then nip off the head of each nail.

Now I can slip the fretboard off the neck and know that when I put it back on, it will be in exactly the same position.

I make a plywood caul that is just a smidge wider than the fretboard itself, and drill holes in the caul to allow the nails to come through.  Another plywood caul is used to protect the back of the neck, as well as a small caul that will fit inside the body between the neck block and the upper transverse brace.  This will allow me to fit a clamp into the soundhole and tightly clamp the part of the fretboard that will be glued to the body.

After a dry run to make sure it works as planned and to know how many clamps to use and their best positions, I slather the bottom of the fretboard with glue--except for the very center where the truss rod is--and clamp it all up.  I put some wax paper between the fretboard and the caul to make sure any glue that squeezes our of the nail holes doesn't stick to caul.

This stays clamped up overnight--after an hour or two I bring it inside so I can turn the garage heaters off.  I don't want the guitar subjected to cold temps.  Pam isn't thrilled to have this contraption sitting on the table in the den that she has so meticulously and beautifully decorated for Christmas, but she definitely is afraid of leaving the heaters on overnight, so there isn't even a discussion.

Besides, it's only one night.  The next day everything gets unclamped, and the guitar goes into a case stored out of the way until I get a chance to start shaping the neck.

Monday, December 21, 2009

Truss Rod Install

Before the fretboard can be glued onto the neck, the truss rod needs to be installed.  Before that can happen, some wood needs to be removed.

I've designed this guitar to have the truss rod adjusted at the headstock, so some material has to be removed to provide room for the adjustment nut.

This is done with a chisel and a round file.

However, I can't let it go too high on the headstock or else the trench will leave to little wood at the back of the headstock.  So I'm going to have to removed some material on the body as well.

Now the truss rod fits fine lengthwise, but somehow the channel is not quite deep enough.  It fit fine when I cut the channel, but now the rod sits a little proud of the surface, and this will prevent a tight fit when gluing the fretboard to the neck.  A little work with a chisel and some sandpaper, and the truss rod is below the surface of the neck along its length, and fits snuggly in the channel. 


Here's the Allen wrench in the adjustment nut, showing why I had to cut the channel into the headstock almost twice as long as length of the adjustment nut.

Now it is finally time to glue the fretboard onto the neck!  But I'll save that for another post.

A Pastor's Lament

Since we moved back to Maryland in 1995 there have been 3 major snowstorms: 1996, 2006, and this past weekend.

The Blizzard of 1996 began on Saturday, Janurary 6 and continued throughout the 7th.

The Blizzard of 2006 began on Saturday, February 11 and continued throughout the 12th.

The Blizzard of 2009 began of Friday, December 18 and continued throughout the 19th.

All three of them occurred on the weekend and forced us to cancel all Sunday activities. 

Why, oh why, can't a blizzard hit on, say, a Tuesday?

Saturday, December 12, 2009

Children Hungry in the U.S.

Can't sleep, so I'm up at 3 a.m.  Get online, go to the Washington Post.  Mainly to check sports scores.  I already know the Caps won in overtime, but didn't get a chance to read the whole story.

Before getting there, I see a story on the front page about child hunger in the U.S.  To even say that seems surreal.

Flat screens selling like crazy this Christmas.

Something called a Zhu Zhu Hamster selling for $27-37, with accessories selling for $37.

It's a stuffed toy; why does it need accessories?

How can there be hungry children in the U.S.?  It really doesn't make sense.  I know they aren't starving; there aren't little children with bloated stomachs lying on the sidewalk.

But still, hungry?  I get hungry when I'm on a diet (which I should be on right now, but it's Christmas, right?) but not because there isn't even a single box of mac and cheese in the house.

The article says that the number of hungry children in the U.S. has risen during the recession from 13 million to 17 million.  There are 50 million children between the ages of 0-11 in the U.S., 75 million between 0-17.  Assuming the 17 million figure includes 17-yr.-olds, then 9% of children in the U.S. who are regularly hungry.


Oh, I know, it's a complex issue; that's basically what the article is about.  And, yes, the parents need to be more responsible--she shouldn't have gotten pregnant at 15 and decided to raise the child on her own, he shouldn't have dropped out of school and relegated himself to a lifetime of low-paying jobs that get cut every economic downturn.

But that's not the children's fault.  And regardless of where blame lies, if one feels the need to fix blame, it doesn't change the fact that a hungry child will have more health problems, will have a harder time learning in school, will have decreased motor skills, and that affects all of us.

But even if it doesn't, this is happening in our backyard.


This isn't the reason I couldn't sleep tonight.  But maybe it should be.

Thursday, December 10, 2009

The Fix

When I decided to get into guitar building a few years ago, I started by learning as much as I could about the process.  One of the things I did was to purchase and watch a DVD on building a steel-string guitar by Robert O’Brien.  O’Brien studied luthiery in Brazil and worked there for a number of years before returning to the states.  He now lives in Boulder, CO, where he runs the guitar making department at Red Rocks Community College.  (This school has an amazing School of Fine Woodworking in which building stringed instruments—violins, mandolins, banjos, and classical, steel-string, and electric guitars is a major part.)
About a year ago I had a question about a guitar I was finishing, so I went to O’Brien’s website from which I emailed my question.  He very graciously replied almost immediately, and invited me to join his online forum on which other builders post questions and answers to problems, pictures of their recent successes, and other things related to luthiery. 
Robbie, as O’Brien is known by those who know him, recently posted a picture of his latest classical guitar which shows the bridge—the part of the soundboard that holds the strings—in its proper position but with about ¼” of unfinished wood showing in front. 

 The bridge is glued on after the finish (in this case shellac) is applied and buffed, so before finishing you must carefully measure where the bridge will be and mask this off with tape before applying the finish.
Here’s what happened in Robbie’s words:
“I measured and masked off the bridge a couple of weeks ago. I did the FP (French Polish—a method of applying shellac by hand) and let it cure. Yesterday before going to class, I once again measured, centered the bridge, removed the tape, checked everything etc. I then went in to class and was going to do a demo on how to use a vacuum jig to glue on a bridge. I once again had the ruler on the centerline and the bridge in position. Gregory then noticed that the bridge had been lined up at 662mm instead of 652mm!!! Yikes!!! How did that happen? Well, it so happens that they put the numbers 650 and 660 really close together on these rulers! I looked at the 650 and must have then neatly lined the front edge of the saddle slot with 660. Not only once but twice!! Once when masking off and once when removing the masking tape!!”
He had to scrape all the shellac off using a razor blade followed by sandpaper, measure correctly the bridge location, mask it off, then do the French Polish all over again.

I emailed Robbie and admitted to taking perverse satisfaction in knowing that someone as skilled and experienced as he can screw up, because I screw up all the time.  It’s very satisfying when a process works the way it’s supposed to in guitar building, but that’s a satisfaction I don’t experience near as much as the frustration when it doesn’t.  It seems inherent in any creative process that perfection is not only elusive but near impossible.  There are always things that aren’t going to go right, either because each piece of wood is different, or, mainly, because each builder is human and prone to making mistakes.  When one is made, the luthier is confronted with this decision: can this be fixed, or do I need to start over again?  Starting over again is, in some ways, the easy thing to do.  It’s a blunt instrument.  Trash the wood, get a new piece, and do it right the next time.  Fixing a problem requires more skill as it is often very fine work, but more than anything it requires creativity.  You have to look at the problem and envision what can be done.  When executed properly, the builder is the only one who can tell that a fix has been made.
Obviously, fixing a problem is to be preferred to starting all over again, as long as the end result is an instrument that is beautiful to look at, play, and listen to.  Robbie was able to fix his problem, and the result is a stunning instrument that yesterday sold for over $3,000 within hours of going on sale.

In the flood narrative of Genesis 6-9 God used the blunt instrument of starting all over again to fix the problem of human evil, violence, and sin.  And it didn’t work.
The Incarnation is God using his creativity to fix the problem.  God became human, suffered the brunt of humanity’s violent evil, and won.  None of us would have come up with this plan.  It’s ingenious. 
And if each of us will submit to his incarnational plan, the result, both in our lives and in the world, will be stunning.