This American sycamore and red spruce guitar is coming right along. I’ve completed the woodworking and am deep into the finishing. The box sounds and looks wonderful–sycamore has almost unbelievable figure naturally and my previous sycamore guitars have given me some good practice on getting the most out of this wood. The adjustable neck joint front loads a lot of what is typically final setup work, so this guitar will be playable very soon!
I’ve just begun work on a new 12-fret auditorium in American sycamore (from Callaway County, Missouri) and red (Adirondack) spruce. This guitar will feature laminated sides, an adjustable neck joint (adjustable from the inside of the guitar) and that wonderful snappy sound that sycamore provides. The aesthetic will be pure classic on this one: clean and simple rosette, binding, a slotted headstock, an African blackwood fingerboard and bridge and a warm brown finish.
There are a lot of ways to apply a sunburst. I like to use wood dye and work directly on the wood similar to the method used by violin makers (and guitar and mandolin makers before sprayed finishes became the norm). The method enhances the grain of the wood because dye interacts with it, becoming darker in the areas where the water base of the dye is held and stays wet, like areas with curl in the wood fibers. If you love the quirkiness of wood and like the way that watercolors look, then this method might be for you. It is, however, less predictable than spraying color coats over a sealed wooden surface. I think it’s worth the extra work and a little risk! Continue reading “Making a Dyed Sunburst”→
I’ve recently started a new build, an adirondack and sugar maple 12-fret grand concert guitar that will be clean and contemporary-looking, with a sound port and paddle headstock featuring really sharp-looking Gotoh “X-finish” tuners. Notably, this guitar will be my first production guitar to use double sides and solid lining, which I’m pretty excited about. The goals for this guitar’s sound are a focused bass with good carrying power and trebles that are thick, musical and committed.
In the odd snatches of time while glue is drying or shellac is curing, I’ve been working on a new technique: building guitar rims using two slats of wood per side, laminated together to form a double-thick side (~.150″ thick). It adds quite a bit of complexity to the rim-building process–more steps and added time–but I’m really excited about the new acoustic possibilities. And one of my awesome buyers has agreed to wait a little longer for his instrument, so we can implement this approach to further increasing the contribution of his guitar back to the overall sound.
Why double sides?
I decided to try this technique after reading the excellent book by Australian luthiers Trevor Gore and Gerard Gilet, “Contemporary Acoustic Guitar Design and Build.” I was especially impressed by Gore and Gilet’s discussion of the current state of thinking in guitar acoustics. I’m a believer in responsive-backed instruments; I build lightweight backs braced to encourage the plate to vibrate like a second soundboard. This complicates the acoustics, because the top and back and body cavity (air space) all need to work together harmoniously, or the efficiency of the system is hampered, and you get a run-of-the-mill, un-explosive, disappointing guitar. Gore is also a fan of the live-backed guitar, and he has found that one of the ways to improve the coupling between the top and back of the instrument is to take side vibration out of the equation as much as possible. He also routinely adds heavy weights to his instruments’ ribs to change the relationship of the top to back to body resonances.
Since I had a recent prototype guitar handy, I thought, “Hey, let’s see if this works as advertised.” It did, and even at the measurable rate he estimated (measurements are made by recording thunks on the bridge and the analyzing the recording using an audio tool like Audacity).
So in developing my client’s guitar, I decided that I’d add mass and stiffness to the ribs by laminating together two slats, and use laminated-in-place solid linings instead of kerfed linings. Basically, I’m building a lightweight, guitar-shaped banjo rim and counting on the mass and stiffness difference to dial down the response of the sides and encourage the top and back to communicate more freely.
The method I’m using
I’m pleasantly surprised by the increased stability of the assembled rim. I use a lot of maple, and maple really wants to spring back after bending, but these doubled sides are rock-solid. Once they came out of the vacuum bag, the doubled sides were locked in shape, and I didn’t have to wrestle them into the form to keep their shape. I expect this to take some stress out of the completed instrument body, too.
An unforeseen advantage is that when you’re using two slats, you can make each slat thinner, which is great if you’re using difficult bending woods, like maple. I used .075″ slats rather than my typical .085″ with this sugar maple, and the improved ease of bending and smoothness of the resulting bends is noticeable.
The whole rim, and especially the solid linings, look very cool. I’m shallow, I know, but I want my guitars pretty inside and out, and this finished rim is very clean looking. It looks like the inside of a violin!