Acoustic Guitar Construction

Since the Cherry ladder-braced guitar is about ready for finish, and I have enough Cherry veneer for another guitar, I started a new one. This is my design more or less, nothing radical - soundhole where it belongs, no cutaway etc. I'll be using Lowden-style dolphin bracing, and a simplified neck joint based on the early Taylor guitars, which worked very well. More on that later.

So I just finished making up a few forms and templates. First thing was the plantilla, out of 1/4" mdf, cut to shape and shellacked. I then used that to contour the outside mold, the inside spreaders, the mold for the solid linings, and to cut down the template for the KMG '0' sized Lowden jumbo to the shape of the plantilla.
The lining molds have 3/16" cork/rubber gasket material from O'Reilly's, attached with the masking tape/Ca method. The 'inner' part of that mold - the one with the holes cut in it - was made for .25" linings, so (3/16" x 2) + .25" was removed before gluing on the gasket material. Following Bogdonavich's method.
Then I made a plantilla for 1/2 of the headstock , out of some scrap, and then used that, tape/ca'd to some 1/4" mdf, on the router with a pattern-following bit. Then used THAT to router an exact copy, then glued them together and shellacked. Not shown is that I taped/ca'd that glued up headstock pattern to the headstock and ran it through the router, then drilled pilot holes for the tuning pegs. I picked the shape because it gives a nice straight pull from the tuner peg to the saddle.
I had made the bridge earlier on, out of bloodwood.
Also shown is the side profile - the white poster paper with the blue tape on one end - using the MM process.
4 1/2" at the tail, 3 3/4" at the headblock.
Side lamination is the next step.

This has always intrigued me, so this is what I'm going to use this time:

I've come to really like the sound of small bodied guitars, especially the "growly", well articulated bass many of them pump out. The large dreads and jumbos tend to "thump", loudly of course, but with less definition and fewer overtones. Granted, this is a broad generalization that does not apply to every case, but I've noticed it too often to think it is my imagination.

I've also noticed small guitars can be built much more lightly - probably a function of the fact the smaller the monocogue for any given thickness/stiffness/strength of its skin, the stronger it will be, so the need to beef up is diminished. Thus the small frys can be just as loud as their larger cousins, in the near field, anyway. (I would shy away from putting a Terz up against a banjo. In fact, it might take more than one dread to be heard in that situation.)

Looks like a great start to a great instrument.

The "old" Taylor neck joint seems like the way to redeem the David Russell Young butt joint. I've used a modified version of the DRY joint that features "insurance" that it will not come loose, along with a big piece of steel that renders the neck impervious to bending with humidity or string pressure, and none of them have failed. However, they do require measuring 10 times, maybe more, before gluing. And they scare buyers. But this version gives you wiggle room, both in the original attachment and later adjustments.

Young's theory was that adjustable necks tend to "adjust" themselves over time, and therefore require adjustability, something like a self fulfilling prophecy. His 1/2" x 1/4" steel bar, vertically oriented and set in aircraft epoxy (jet fuel risk to the instrument is thereby eliminated), does not move. Topped with a strong quarter sawed fingerboard, his necks might be classified as lethal weapons.

Dave, I am certainly in no position to advise or judge neck installation techiques, there seems to be a zillion of them. I looked around at a bunch before I picked one, and I spent a good amount of attention on the Mottola essay and photos that you attached. Seeing as I didn't know what I was doing, I decided to take comfort from a comprehensive set of instructions that were part of a neck attachment system parts package I bought from 'Luthier's Cool Tools', Rick Micheletti's supply business. What he's selling is something that is highly reminiscent of Collings', Bourgeois' and Gore's neck attachment systems. I liked the idea of flush bolting the neck to the face of the body, no mortise/tenon, no dovetail, and I liked the way the neck was supported and kept straight below the 14th fret. Might be worth a look as a permutation of the process Mottola presented.

Thanks Peter.

John - I have my hopes .
I'm really hot to get the ladder-braced git strung up as well.

Odds and ends in the shop today. I've got the 'double back' in the vacuum bag and on the 15' dish and will let that cure overnight. I used TB original, as I've found that a good 'wet' application, rolled on, works as good as anything else I've tried. The inside layer cracked down the middle, but the vacuum process heals things like that. The outside piece is fine - the cherry is 16" wide so there was no gluing of half-sides to be done. The Thin Air Press bag, as I've said before, just does not leak.

I cut a bunch of strips for the solid linings.
Made a clamping caul for laminating the sides. The outside mold doubles as a clamping form as well.
Got the bending pipe out and ready for a little bending in the morning.
Made a little sanding jig for the back patch, following Bodonavich's parameters. The back patch would not be needed had not the inside layer split - luckily, it split down the middle so the patch will cover and enforce it. The patch is really not needed usually.

That's it for today, lots to do tomorrow.