Acoustic Guitar Construction

Once the epoxy cured (the next day) I profiled the the primary and secondary falcate braces. I plan to leave the height of the braces around the bridge 7 mm, My guess is the resonant frequency of the top will end up around 180 Hz. I found the 00 ends up with a higher top resonance than than Gore medium steel string with the same brace heights as it is a smaller guitar. I then epoxied down the all but the upper transverse brace. One might notice that a sound hole top doubler patch showed from the last post. I noticed I forgot to install it before I put the falcate braces. No problem I cut one out and installed it.

Once the epoxy cured (the next day) I profiled the the primary and secondary falcate braces. I plan to leave the height of the braces around the bridge 7 mm, My guess is the resonant frequency of the top will end up around 180 Hz. I found the 00 ends up with a higher top resonance than than Gore medium steel string with the same brace heights as it is a smaller guitar. I then epoxied down the all but the upper transverse brace. One might notice that a sound hole top doubler patch showed from the last post. I noticed I forgot to install it before I put the falcate braces. No problem I cut one out and installed it.







While the epoxy was curing I spritz a set of reverse kerfed linings and while wet clamped them on the outside of the sides. This is sort of prebending them to avoid breaking them when I am installing them. It is amazing how well they take the shape after them dry.



I installed them one at a time.



I finished the day laying on carbon fiber tape on top of the braces.

Good work John. Do you think the carbon fiber strips do a lot?
Herman

Herman wrote: ↑Fri Jul 19, 2024 11:41 am Good work John. Do you think the carbon fiber strips do a lot?
Herman

The main value of the CF strip is preventing cold creep over time. I also get better stiffness consistency by having 15-20% of the stiffness of the brace in CF. There are two strips one above and one below the brace. Once I have the upper strip on the top nearly perfectly holds the radius. It seems to be doing something.

The downside is once the CF is on there is no way to tune the braces. That is where the consistency helps, The braces are all sized to spec.

I have a few more days into the project Finishing the top bracing I decided to spend a few hours making the upper transverse brace on the CNC instead of by hand. Still it was a CNC learning experience; also the radius is a bit complex 28' on the edges with a flat section in the middle. While it is easy to radius the brace and then flatten the center section (where the fretboard sits), I was able to build an exact reverse caul to help clamp.



I still needed to cut the rebates for the falcate braces and the sound hole braces by hand. I set the heights of the rebates to match the height of the braces, cut to the vice with a razor saw and clear the channels with a chisel.







Then using the CNC made caul I clamped the upper transverse brace onto the top.



With the top bracing finished I spent quite a bit of time setting the neck angle into the top. From my initial profile work early in the build I was close but the top had a bit too high of an angle.



I used a plane to fix the profile, A bit at a time I lower the sides around the waist and on the fretboard extension. I continued to work the extension of the fretboard until the extension was right on the bridge.



I cut and radiused all of the back braces from stock I made earlier in the build. Rather than using a my gobar deck, a real pain with the 10' radius and the gabled braces I glued them one at a time using a radiused board and cam clamps.









A little time with the chisel profiled the braces. I also spent some time with cleaning up the rims.



Just a little bit of work and I can close the box.

Really looking good John. That bracing seems to be alot of work!

Kevin in California wrote: ↑Wed Jul 24, 2024 10:03 pm Really looking good John. That bracing seems to be alot of work!

No doubt! That why I still do X braced guitars. I can brace and voice them in a day. This was a request for a falcate braced guitar. No issue. I am taking things slow now in any case and just enjoying the process.