neck fitting dovetail archtop

[Brian Evans]

There is something about fitting a dovetail neck on an archtop that I don't understand. How do you scribe and fit the neck extension to the body when the dovetail is a tight press fit into it's final depth? It seems to me that if you leave the neck joint loose enough to be able to fit it all the way on to scribe and sand the neck extension to the top, the neck joint is then too loose for a proper fit for gluing. What am I missing? I feel like there is something totally obvious that I'm not seeing.

Brian

[Christ Kacoyannakis]

The neck extension is glued on after the dovetail neck joint is cut and fitted. This allows you to use a router and a dovetail jig to cut the neck dovetail. Once you cut and fit the dovetail, then you glue on the extension and can shape it to fit the top. Now, I have heard some people claim that D'Angelico's neck extension did not start until about an inch onto the body, which did not allow him to use a router, so the dovetail had to be cut by hand. He probably did cut the joint by hand, but due more to the fact that routers were not widely used during the time he was making guitars. However, if you wanted to do it like that, and cut the joint by hand (you would have to) then it would be just a matter of leaving the dovetail a little wide, and then starting to fit the extension as the dovetail was fit, and then go back and forth (a whole lot of times!). Save yourself the headache, and just cut the dovetail first, no matter how you do it, and then work on the extension.

[Andrew Armstrong]

Hi Brain, I realize your original post was over a year ago and no doubt you've figured it all out by now but I'd appreciate hearing more about this.

My understanding is that the DT joint should not be a tight fit initially so it is easier to fit the fret board neck extension to the body. Once that is done the DT joint can be tightened up with shims as required.

I'm also interested to hear views on whether the DT should be tapered or straight sided. Benedetto implies a straight sided DT whereas the more conventional DT neck joint for a flat top guitar is tapered. I think fitting a tapered DT might be easier but again would like to hear views of others.

Andrew

[John Clifford]

I don't think there is any easy trick to making a perfect joint. You can get a good preliminary fit on the dovetail before adding the neck extension, as Christ says, but it always seems like everything you do affects everything else. I almost always have to use shims in the end, no matter how well the joint fit before the extension went on. No shame in that, I guess. But whatever you do, don't use paper as shim material. I learned that the hard way. I use a tapered joint, because it seems to me it's easier to adjust.