Armed with a new neck removal jig, I can take on the first of four (count 'em...) neck resets waiting in the queue.
This is a garden-variety Guild D-4. Mahogany back and sides and spruce top. This particular guitar was built in 1992. You may recall my earlier work on this guitar - mainly installing a JLD Bridge Doctor to reduce top bellying. It did that, but it didn't do much to change the guitar's high action. A neck set is in order.
Side note: you gotta love wide-angle lenses (this is about a 24mm). The guitar looks like it's bigger than the trash can and the heater on the floor!
I measured 13/64, or .203 of an inch. We'll need this number later to calculate how much wood needs to be removed from the neck heel to correct the set.
As you drill, you'll first see the fingerboard wood's chips (in this case, rosewood), and then the neck block's (mahogany). If you see too much of the neck block's wood coming up, you're not in the dovetail joint - you're most likely in the block and you'll need to angle the drill differently.
The sawdust here is rosewood. I saved this to re-use when I fill the holes later. I'll need more, but maybe I can use this on the top layer of fill to try and match the fingerboard closely.
You'll know when you hit the joint - in this case, the bit went in about 3/4 of an inch, then just dropped down. I have a picture of the block that will show my exact angles.
You don't need to drill 2 holes. Some folks just do one - but I wanted a second hole for steam to escape.
I use the 'cotton' setting - almost the highest - on some foil for about a minute.
The heating is to weaken the glue that holds the extension to the body of the guitar.
It took a few rounds of heating with this one. Once I could get most of the blade in, I left the knife in the joint when heating again, so that the knife was hot as well.
The wood here is pretty flexible - you need to be careful and slide the knife in and not pry it upward. You could snap the fingerboard off with too much upward pressure.
Take your time, heat as needed, and the joint will free up.