Taking a Break

What a difference a few days can make here in New England. My last post was about being locked down by the snow, but now it’s sunny and (relatively) warm. Accordingly, I took a few hours out of the day to stack up what will hopefully be the last of this winter’s firewood.

It was a bright, crisp afternoon—the kind that makes you feel great to be alive and privileged just to be outdoors. I worked at a steady pace piling up the logs, breathing deep and stopping every so often to look at the trees and sky. Just a few steps away was our suet feeder, which attracts larger birds. As I labored, wrens, bluebirds and thrushes flitted back and forth from the nearby trees to the feeder. A noisy group of three downy woodpeckers alternated with the bluebirds and wrens for a shot at the food. At one point I grabbed my camera and got a photo of a bluebird patiently awaiting his turn while a male downy woodpecker feasts.


Once the last of the firewood was stacked I went inside to finish up the drawings for the cherry blossom guitar. The shape of the front and back plates had been finalized so it was time to cut them out of steel. My first step was to make paper templates from my drawings so I could check the shapes with the actual guitar parts.


Then it was time to get medieval on a sheet of .059″ CRS. I had a piece that was just big enough for two sets of plates, and with a little luck I’d be able to cut them without problem. This thickness will allow the engraver to go deep without denting or puckering the plates. I chose steel because of its magnetic properties. Aluminum is fine for laser or chemical etching, but it messes with the inductance of the pickups in a way that isn’t as kind as copper or steel. Besides, I’m going with hand engraving—steel will yield better detail.


Here I am checking the overall fit before drawing out the shapes on the metal.


Using some spray adhesive, I fix the templates to the sheet so that I can trace the outlines with a scribe. I want to get the material into more managable pieces.


After transferring the shapes, I roughed out the blanks with an air shear—not my first choice of tools, but it works. This gets me close enough so that I can finish the parts on the bandsaw and then the spindle sander. which is a job for another day.




Carving a Niche: Crow Guitar Neck Shaping

The snow has let up for a while, which means we can get back to making more cool stuff instead of raking snow off the shop roof for the third time. I wasn’t really too worried about collapse, but it was a good excuse to go out and play with big-boy tools in the snow. Out here in the woods it’s really beautiful and the morning light on the trees takes your breath away.


I’ve always marveled at how guitarists find it perfectly acceptable to take a brand new instrument to their tech for a setup. In my opinion, a guitar that needs fretwork out of the box wasn’t made properly in the first place.

It’s been six weeks since The Crow’s neck and fingerboard were bonded together—just the right amount of time to do the final relief on the back of the neck. The idea is to let the neck twist or move completely before you radius the fretboard. I’d done a study of neck twisting years ago, and the results were quite interesting. I used two groups of ten necks—one in the shop and the other in a controlled environment. Every day I used a vernier clinometer to measure the amount of twisting that had occurred, and the data was put into a spreadsheet. Just to make sure that the results were correct, I repeated the same test six months later. Same conclusion.


All of this was to put some real numbers to what I’d speculated all along by the seat of my pants. It all comes down to a sort of actuarial exercise depending upon how much risk you want to take with your guitar. There is a point where the risk of a twisted neck becomes “acceptable” compared to how many warranty claims you’re willing to remedy. In the case of a guitar I make today, the risk I’m willing to take is zero—so I go for the full maximum time. That means that the neck and fingerboard assembly will sit on the shelf  for the full eight weeks. This is the true point of diminishing returns as far as I’m concerned—and the data backs it up.


Now that we’re at the six week point, I take the neck down to its final shape using a cabinet scraper and then sandpaper. At this point the “normalization” process is almost complete. The fingerboard is still flat, and that’s the secret to the whole thing. In two more weeks, after all the twisting has finished, I’ll cut the final radius on the fingerboard. Because the wood has done all the moving that it’s going to do, the playing surface will stay true for the life of the guitar. An added bonus is that I won’t have to “true” the frets, which is really just “truing” the neck called by another name.



Crow Guitar Neck Assembly

The slower you put things together, the slower they fall apart.
—John Grail

With the holidays upon us, I wanted to get some things done in order to take advantage of the break. Typically, I let complete neck blanks set for eight weeks after the fingerboard has been glued on.  This allows the neck components to take a set before the fingerboard radius is machined. It’s better to let it warp or twist first and then machine it straight than to let it change afterwards.


In this photo, I’m cutting a length of cold-rolled 3/16″ steel rod to the prescribed length, before threading each end with a die.


I use a 1/2″ diameter hex rod cut to a length that puts it just under the fingerboard for the anchor end. After drilling and tapping a through hole, I insert the 3/16″ rod and screw it tight before mig welding both sides.


Good penetration is important because the last thing we want is for the weld to let go once the neck is built.


Getting a solid weld without making too big a blob is the order of the day. Here, I’m cleaning up the weld with a file to make sure it clears the slot. Now it’s ready to go into the blank.


While I’ve been making the rod, Jim has bonded the ebony faceplate on the headstock and is using a plexiglass template made from my drawing to mark the rough headstock outline for reference.


After coating the rod with paraffin, Jim slides the rod through the adjustment hole and taps the anchor down with a mallet and dowel. A spline of mahogany cut from the same piece as the neck blank is used to seal the rod into the slot before the fingerboard goes on.


I’ve designed an inlay that I call “Claw” and fitted it at the 12th fret. It’s a combination of mother of pearl and green abalone—seven pieces in all. This is done before the fretboard is glued to the neck blank.


Here’s the fretboard dry fitted to the neck before bonding. The rest of the fret markers are two different sizes of pearl dots for a clean sophisticated look. The final taper of the neck includes the space for fingerboard binding


It’s only a matter of spreading the glue and getting the whole assembly into the clamps. After that we can head home to our families, while time does what man cannot.




Crow Guitar Rim Shot

Good progress is being made on The Crow guitar. The top and interior templates have been made from baltic birch based on full scale drawings refined from my sketches—now they’re ready to go. Here are the steps below: the drawings, the  templates and the interior of the rim, which in this case was routed from Honduras mahogany.


The center block still has to be routed with the three different size tone chambers that I want to put directly under the bridge and tailpiece. Each chamber is a specific volume which relates to a different frequency range. This breaks up the spectrum and evens out the response when played at high volume. It reduces the tendency of the guitar to howl on a single note.

This is the rough rim placed on the spruce top which was being routed in the last post. The next task is to carve the interior of the top, then bond it to the rim. When the top and back are glued up, then the outside can be finalized and the top and back carved. Traditional archtop builders carve the entire top before attaching it to the rim—tapping as they carve to determine the thickness needed from each individual piece. In my case, I like to carve the interior, then carve the outside—tapping the entire assembly as one.