Acoustic Guitar Construction

Making a bit more progress mostly working on the rims. It has been a while since I made a Spanish style neck joint.

I used the LMI circle cutter to mostly cut out the sound hole. With the sound hole doubler patch I need to cut about 4 mm deep. A bit much for one pass. One bad feature of the tool is that I need to back out the radius to get the hex wrench on the set screw for the blade. Screw that! after I made the initial cut I pulled out the router and left just enough wood to keep my pilot hole center. I did have a nice clean knife cut on the top.







I marked and beveled the sound hole patch to make it look good from the front.





I also trimmed the neck side of the top real close to the final profile to fit on the neck heel.





I grabbed a sycamore side from my stash of orphaned sides I have bought over the years bent it and ripped it to make solid linings for the top. I also had a pre-bent EIR side hanging around for a few years, so I also popped it back into the bender and riped it to make fancy laminated linings.







I just used my mold with another bend side to laminate the stack. I just used LMI yellow glue. Never enough clamps though. I needed to do one lining at a time.







By hook or by crook I got the solid linings in the top and reverse kerfed linings for the back.





During the binding glue ups I made the fret board and worked on cleaning up the headstock







I glued a 1mm thick strip on the base side of the fret board and then thickness sanded it. Now the base is 1 mm thinner than the treble.







I re-radiuded the back of the rims, also along the way I profiled the fretboard.



I have yet to glue the sides to the neck so I removed the sides and will be ready to profile the neck tomorrow. Hopefully I will also finish the rims with a mass support block and some of the side reinforcement strips.

Sorry I have a big post. I have the rims nearly ready, I have braced the back and have one remaining brace for the top.

To finish the rims I added a couple of the mass blocks, that would allow me to tune down the top a bit after finishing the instrument. I also added a bunch of side reinforcement strips.





I used de glue do to clean off the harden glue. I got a bit sloppy



Around the same time I ripped a bunch of 1.7 mm englemann spruce strips and bent them on a hot pipe. The engelmann really bent easily for me this time. I used german spruce on my last classical and that wood was not happy about bending. I was amazed at the difference. I used West system 105\206 to laminate the falcate braces on the forms.







The next day I ripped them in half on the bandsaw, sanded them flat and prepared to epoxy them to the top.





I make sure that I have everything ready before I mix the epoxy. Once mixed I try to work quickly but more and more I try to be a bit neater.





It took me two session but ultimately I got them all epoxied. I then profiled the braces. For this guitar I am going to use 10 mm for the main falcate braces and 7 mm for the secondary. The braces all need to be profiles before they are capped with another strip of CF tow.





Note the effort I made to force the top to follow the solera before laying on the fiber.



The Solera has a 2 mm dish in the lower bout.



The back is a little more conventional. As per the book I pre profile the back braces with a 22.5 degree chamfer bit.





I will brace it has an active back, using 3 transfer braces and a set of radial braces



I used a combination of a plane and a radius brace sander to put the radius on the braces.







I glued the up in my vacuum box on a 15' radius disk.



I was able to find and use my handy brace end profile jig, and made quick work putting the profile on all of the braces.





Another couple of days and I will close the guitar.

Sorry about the previous long posts with pictures. I will break up todays into a few posts.

I added the upper transverse brace to the top. This is a bit of a pain as I inlet all of the braces that cross its path. As shown in the pictures I clamp the brace down, carefully mark the brace crossing with a scalpel and then use a razor saw and chisel to make the cut out. I set the brace right to the cutline in the vice and use the vice as a stop. I finally learned after many guitars how to keep the saw straight up and down.
















Then I just clamped it down. As I did not use any CF for this brace, I could have used yellow glue, but to stay consistent I epoxied it down as well.



Next up final prep for the wings.

I took the time to profile the upper transverse brace (no pictures).

I had to do the final prep of the rims. I notched out a rebate for the lateral braces both back and top. I use a pencil mill grinder. I also notched cut out a rebate for the end graph. I just used a scalpel to mark out the cut and a razor file and chisel to cut and clear the rebate. I have some Petros Guitar shop Purflex that will match the maple purfling on the bindings and the ebony binding that I will use. I will install the purflex after the binding. Before routing for the bindings I wedged in a strip of ebony so that I had a smooth surface for the binding machine to register.
















With everything ready I started closing the box. I glued the sides to the top with the neck clamped to the solera to force the correct neck angle. The angle does not rally get locked until the back is glued on is well with the top and neck still clamped the the solera.



Before clamping the back I cleaned the inside of the guitar again and routed the over hang of the top flush.



The back fits on nicely so I clamped it on as well, again note that the neck is clamped to the solera to force the small forward angle of the neck.



All cleaned up





next the bindings

The back bindings are simply ebony with a maple prufling. The top will have a multi-line purfling to give it that traditional classical look. I tried adding some red and green lines from the rosette but I just could not do it. So I ended up with a black, rosewood and maple stack that I will install.



I carefully set and test the binding jigs cuter depths and routed the back for the bindings. I had a bit of chip out right on the outside curve of the upper bout. It was about 3/14 inch deep and an inch long. I found the pieces but it would have been a mess to put back together. Luckily I had the cutout from right next to the chip out. I clean the chipped out area straight and square with a chisel and glued on a small strip. Sorry no pictures of the damage but here is a picture after the repair. The repaired area is right over the chisel handle



The biggest pain for spanish neck joint guitars is having to install the bindings with the neck on. I start with a scalpel and a template to continue the binding line. I use a purfling cutter to continue the cut on the sides. I increase the depth with a razor saw and clear the waste with 1 mm and 2 mm chisels. It is a real pain.






The test binding seems to fit.



After that it is just a matter of trimming the bindings and installing them. I used a scarf joint for the bottom and a butt joint for the top. When working with a scarf joint I install the binding with inward cut first. That gives me a solid notch to insert the second binding into. I am really able to push it tight that way.










Next up is the top binding.

Love it. You're really moving along.

Thanks John,

I finished the bindings, added a scrap piece of purflex for the end graph and have started finish prep.
I still need to make a bridge.