Acoustic Guitar Construction

After a bit of a hiatus, I'm back at work on the classical.

I decided to go with a bolt-on neck, as well as a radiused top. Creating the top and back plates has gone pretty smoothly, and I'm happy with the results. I got a bit puzzled over the mysteries of "tap tuning" with my top plate, but after lots of reading and chatting with people decided that I was as likely to worse as better by over-thinning sections, so am leaving it as is right now.

The bolt-on neck wasn't quite as easy as I'd hoped. The main problem was not retaining squared edges on my neck (particularly the heel block) until I was sure I had dead on 90 degree angles where the heel would meet the body (both vertically and horizontally). With some taper in the sides of the neck it became really hard to trim the end of the neck block on a table saw.

So, lots of time wasted fidgeting with the fitting after carving the heel. I did carve out a shallow relief pocket at the end of the heel so that only the outer 1/4" or so of the heel outline is actually contacting the body. This makes the "flossing" easier for fine tuning the adjustment. I'm almost there; initial measurements show it's pretty darn centered on the body.



Here's a snapshot of the body with the two necks (one a "test neck").



As I'm now moving toward closing up the box and routing the binding channels, I'm sure I'll have questions along the way. The forum topics on binding have already been quite helpful.

Looks great!

I believe you can shave your heel relief to about .07" makes fitting easier. Huss and Dalton use a butt joint bolt on system (they have videos showing construction). Standard design for a butt bolt on includes a full length dowel in the heel to help prevent cracks, some even use aluminum rod.

ken cierp wrote:Looks great!

I believe you can shave your heel relief to about .07" makes fitting easier. Huss and Dalton use a butt joint bolt on system (they have videos showing construction). Standard design for a butt bolt on includes a full length dowel in the heel to help prevent cracks, some even use aluminum rod.

Thanks Ken! I did use a dowel most of the length of the heel (inserted from the top side of the neck).

I'm confused about what you mean by shave your heel relief to about .07" to make fitting easier? Do you mean the part of the heel that makes actual contact with the body can be taken down to .07"? Mine is down to about .25". I would worry that a really thin border around the heal would crush the wood under compression.

Hi Larry,
I understand your concern regarding the thin perimeter if your plan is to carve and leave a ledge. But I am not suggesting that methodology, conceptually what I suggest is to hollow out that area in a shallow taper leaving the .07 or so at the edge. As shown here: http://www.kennethmichaelguitars.com/neckfitpart1.html

So when you floss (if needed) the restricting edges sand away easily. As for crushing the edges, glad you brought that up. Its easy to over tighten neck bolts and sometimes break loose the insets (not a problem until its time to remove the neck). The bolts should be just tight enough to compress the Belleville washers.

Ken,

We're on the same page - your method is what I'm more or less doing. Yes, it was the thinness of that edge that concerned me, and I'm glad you brought up the point of not over-tightening, too. Given that I'll be reaching through the sound hole with a long Allen wrench (holding the short end) I won't have a lot of torque to play with anyway.

Thanks again,

Larry

Wow, it's been nearly a year since I've updated my progress. Guitar #002 was finished and strung up sometime last October or thereabouts. Construction proceeded fairly routinely, with a few notable exceptions.

At one point I managed to sand completely through the top to the tail block. The next few pictures show the flaw and how I patched it using a laser cutter to engrave a half-circle, excavated it with a chisel and installed a patch of black veneer. It didn't look to bad after all was said and done.







The other challenge was getting the French polish right. I started off applying it way too thick, and called in a professional woodworker friend who'd trained under a master refinisher. He basically showed me how to apply very light coats - not that different than one might find in YouTube French Polishing videos - and the finish was satisfactory.

I'll take some more photos of the finished product eventually. I'm already on to #003, trying not to make the same mistakes I made in #002 (but, as it turns out, making brand new ones). Stay tuned...