Sexauer Classical Guitar (2015)
 

I haven't previously posted in this category,mostly because I haven't made any nylon strung guitars since I started participating in AGF. My last, owned by Duck Baker, was made about ten years ago, and before that it was the '70's! I have been thinking about it for sometime, however, and without a customer in sight I better get to it before I run out of time. It will be BRW/Italian Spruce, and will be a relatively conservative piece, being "classical".

http://mojoluthier.com/lpics15/252N/top1.jpg

http://mojoluthier.com/lpics15/252N/back1.jpg

http://mojoluthier.com/lpics15/252N/topbraces.jpg

I'd be happy to hear your thoughts behind the bracing pattern you've used. I'll read a post as extensive as you'd like, by all means :)

Bruce, I often spy on your builds over on the other side, and I'm always both terribly impressed by your work and a little bit saddened by the fact that I'm unlikely to play one of your masterpieces any time in the foreseeable future. I was thrilled to see you starting on this build, and I'll be following along closely (in silence, as usual). I'm sure this will turn out to be yet another instant classic, so thank you for sharing!

Bruce,

Not being a luthier, I can't comment intelligently on the bracing pattern you are using for this guitar, but I can say that's a lovely set of Brazilian. I have also enjoyed following your builds on the AFG over the years. Keep up the great work and making people happy with your amazing guitars.

Bill

Looking forward to seeing and hearing the result of this build. This despite the fact that just the wood set (BRW) is beyond my pay grade (smile).

Dave

I labored a bit over deciding to use Brazilian for this guitar as I have read about the reticence of classical players to undertake the hazards of international travel with such guitars. On the other hand, I have no expectation of selling to such a player as I have essentially zero reputation in that world, and I believe that most classical players consider that important. I truly believe that Brazilian in the best material, and I have more than I am likely to use n this lifetime, so I went for it.

Not unlike steel string guitars, classical guitars commonly fail over the long haul due to the neck caving into the body largely due to distortion in the top around the sound hole. My bracing above the sound hole is intended to mitigate this tendency.

Looking at over a dozen traditional and contemporary lower bout bracing systems, and choosing NOT to do a lattice system instead favoring tradional construction, I noticed that nearly all have a center fan brace. I have read many times that guitars function as a dipole rather than a monopole (which seems intuitive) and therefore the center brace seems I'll advised, adding mass where unneeded. Besides, I like to be a bit deifferent. The lower cross braces on most guitars seem too close to the rime to me, and especially at the tail block, so I moved them. The finger braces are unusual, I believe, and are a very big deal IMO in steel string construction, so should have meaningful impact here. I expect that impact to be in the treble.

I do not believe the bracing patten is really all that important as long as it adds adequate structure, distributes the lines of force evenly, and avoids all possible unnecessary mass. In the end the guitar will work as it does, and then I will get judgmental, and you will be welcome to as well should you get a chance to play it.

From a person who only builds classical guitars, I think it's going to turn out to be a bit over braced, which will tend to limit the power. Not much driving force in nylon strings.

I am surprised to hear that about the over-bracing. The fans are 7/32 wide x 5/32 tall, roughly, which is less than Sloane suggests given that they are triangular in cross section. And then there are 6 of them rather than the typical 7, let alone what happens in a grid. I think I have a pretty good feel for the strength of wood, less of a feel for the tension of nylon, but in the end it will be what it is. Perhaps you will get to play it and then we can discuss it. It will be a 660mm string, I might add.

I wonder about the pair of short braces on the edge of each of the lower bouts, the ones perpendicular to the fan braces. I don't recall seeing those before on classical guitars. (but then again, I am not a luthier, and I spend much more time "topside" with classical guitars) :)

Sometimes pictures don't tell the whole story, but I'll compare it to my current bracing pattern, which compares, on stage, nicely, to a couple of $8,000 + concert guitars by renowned makers. This from the teacher of the owner of the guitar, in a university program. The cross braces are 3 mm wide by 2 mm tall, and chiseled in the gaps to a slight triangle. The fans, vary in height from the outside at about 3 - 3.5 mm wide x 2 mm high, except at crossover points, to about 4 mm high at the center, also tapered. Lutz Spruce top at about 2 mm in the wings, 1.9 mm at the tail and about 2.2 to 2.3 mm in the bridge area. I don't think scale length will make much difference, but my guitar happens to be a 640 mm. I would build a 650 using the same parameters I did for this one. The bracing is all Lutz Spruce as well. It's what I use on all my guitars now for bracing.

http://i267.photobucket.com/albums/i...pszxuflrg7.jpg

http://i267.photobucket.com/albums/i...psbehslons.jpg

http://i267.photobucket.com/albums/i...ps7zkwk8cj.jpg

http://i267.photobucket.com/albums/i...pscjpq637m.jpg

http://i267.photobucket.com/albums/i...psh82bbuof.jpg

Yes, those are the ones I refer to as finger braces in post 6.

Bruce - why not a bolt on neck as a strategy to deal w/ neck re-set?

Too close to making banjos.

That was exactly my first reaction as well.

In the '70's, Grit Laskin used "finger" braces on classical guitar tops, though his were more radially oriented and much smaller than yours, in height and width. I made a few classicals that way, but later eliminated those braces.

What is wrong with banjos?

Just kidding. On how high Bruce's braces are, shouldn't the plate thicknesses also come into play? Learned that from him with his all Walnut, thinner top and bracing to keep things happy.