Cutting a dovetail mortise

[Talladam]

Hi all! I am about to make the neck block for my first guitar and I am intending to hand cut a dovetail joint. I was originally planning to cut the mortise after the box was closed (I found a good tutorial online), but now I am wondering if I should cut the mortise into the block first and then glue it to the sides. It seems like John here on the site is a proponent of cutting the mortise before gluing the block in, but is there anyone here in favor of cutting the mortise after closing the box? Also, any tips on cutting the joint? Thanks in advance!

Adam

[MaineGeezer]

The luthier who taught me about building guitars cuts the mortise after the block is glued in place. He has a fixture the holds the the guitar body vertically and a V template that clamps on the top (i.e. on the end) of the guitar body. He uses a router with a dovetail bit that has a bearing on it to follow the V template and cut the mortise.

I don't know the relative merits of doing it that way vs. cutting the mortise in the block before gluing it in.

Carter also cuts the joint so it's a bit loose, then shims it to final fit, vs. aiming to make it tight with no need for shims.

[Bob Gleason]

Cutting the female part in the body takes some pretty good skill and very sharp tools. I tried it once, and that was enough. These days I cut the female part with a router. The tail on the neck is very easy to cut by hand. I like Japanese Dozuki saws for this, but any fine tooth backsaw would work. Cutting the tail by hand makes it easy to make small adjustments. Do the layout carefully and cut just on the outside of the line.I make a dozen or so body shapes on guitars and ukes, and it is very common for me to have the female template slightly off, one way or another. A half a mm can make a big difference when it is compounded by 2 router cuts. When I used to cut both with the router, there were a lot more major mistakes.