Acoustic Guitar Construction

As I am building the same guitar as my last. I decided not to blog this build, I will highlight any new procedures that differ from last project. This guitar is a commission from my classical guitar instructor. He loved the sound of the last more importantly though is he really like the ergonomic features I added. Slightly narrower nut and the 20" radius on the fret board. He also like the cutaway. For this guitar I selected a nice engelmann spruce top and panama rosewood back and sides. The tap quality and the stiffness of the rosewood was outstanding. I picked up the rosewood set a couple of years ago from LMI. I went totally classical and chose spanish cedar for the neck. Other than the wood the only design difference is that I will make the braces a mm taller based on the results of my last guitar. Also I am trying to avoid all of the hidden mistakes I had in the last one. So far that is going well.

So far I have the rims built and profiled, the neck has been prepared and I am starting on bracing the top and the back.





I went away from my neck jig and just used a table saw for the tenon. The advantages of the table saw is I can still set the neck angle, but I van also angle the cheeks making it easier to fit the neck on the body. Also the procedure was so clean compared to mucking with the 1/2 inch router bit. I have a sawstop saw, so I am less nervous about cutting my fingers off. Ultimately I will build a sled to make this an easier process. The neck will be a bolt on bolt off neck. The Spanish cedar glued to the fret board will be planed to a wedge to create the negative angle required for a classical.









I posted my rosette build viewtopic.php?f=9&t=2291



Today I installed the sound hole patch and am starting the back

I like that idea for the back strip reinforcement alignment.

John, It looks like another great build coming together. Interested to hear more of your thoughts on the table saw vs neck jig for creating the mortis and tenon. I just picked up a used Simpson jig a few months back, but have yet to use it.

I just used your back reinforcing strip alignment idea last night while glueing up a figured maple back for another 00-12. Works great.

Your posts are a great source of information and inspiration.

Daniel P wrote:John, It looks like another great build coming together. Interested to hear more of your thoughts on the table saw vs neck jig for creating the mortis and tenon. I just picked up a used Simpson jig a few months back, but have yet to use it.

I just used your back reinforcing strip alignment idea last night while glueing up a figured maple back for another 00-12. Works great.

Your posts are a great source of information and inspiration.

Thanks,

I used my Simpson\Woolson like guitar neck jigs for quite a few guitars. The main feature it offers is the ability to set the neck angle for the right saddle height based on the built guitar body. I quickly moved away from this feature because if the body's upper bout did not have the correct angle one had a situation where there was either a body join hump or a ski jump on the neck extension. So I take great care to get body correct and then build a neck with the designed angle. The jig still allowed that, I just set it to rout the angle I wanted. I decided to try the table saw for a few reasons. One, is I have a new sawstop saw so I am less afraid of cutting off my fingers. Two, I have a nice blade that makes a really clean cut. Three, I can cut the cheeks at a slight angle making it easier to floss the correct angle; the relief is built in. Lastly I tired of pulling out the tool, adjusting it, getting the router setup with 1/2" mill getting the neck correctly mounted and then making a mess routing out the waste. The table saw worked out well and was a lot cleaner. Now if I were cutting dovetails instead of mortise and tenons I would use the neck jig.

Bit by bit with my travels, I am going to be starting to put the guitar together. I have the rims, top and the back ready to close the box. I will route the rims for the braces and double check my neck angle and then close the box.

I was a bit more deliberate while epoxying on the braces and CF and overall I was less messy. Still have a ways to go in that regard.

Oooo lah lah. Moving right along there. Nice and clean on the inside.

Thanks Kevin,

Well I did one step forward, about 8 steps back then forward again.

I closed the box successfully, but when I tapped the closed box I was not happy with the resonance frequency of the top. It ended up about 10 hertz lower than my target. I was pretty sure the guitar would end up close to my first. As I really wanted to hear would the higher pitched top would sound like I ripped off the top with plans to make another.

I put the project on the back burner and built a top for an eight string classical guitar with higher falcate braces (8.5mm) and ended up with a top pitched at my target.

So I am back on this guitar. I made the new top, glued it to the rims and back and got the bindings on ...

I pulled the first top I was using for this project. I accidentally spilled a bottle of brown stain on the top after the rosette was installed and put it off in disgust. Well the stain came off with light sanding so I had a top with a nice rosette all ready for bracing.







The Australian Blackwood bindings for the cutaway side I bent in the fox bender were cracked so I bent new ones on a hot pipe. A fun job but I did learn a few things about bending on a hot pipe. First after very carefully achieving a perfect bend for the waste and cut away sections be careful. One can still crack a side bending the lower bout. Also I bent these purflings dry. I use a very very hot pipe. I found the wood got plastic much quicker dry, probably as the moisture keeps the wood closer to 220 degrees as it evaporates. Bending by hand I ended up with bindings that fit without having to be forced into the channel shape wise. Also I used a long fabric strip to bind the bindings after I glued them on. I have a 10' radius on the back. The binds fit the profile but they still need to be forced to the back radius. That forcing wants to twist the bindings a bit so they pull away from the channel. Binding them helped close any gaps.










Also I am happy with the resonance frequency of the box now. I think when I finished the guitar it will be very close to my target.