Hello all, Thursday is the day when I try to have the necks ready to fit into the body for glue-up. Like everybody in this business, I have my own little ways of going about things. Here is how I get a neck ready to glue onto one of my guitars. Before gluing the neck onto the body, the neck is final carved, fretted, and sanded to a "finish ready" state. The next step is to check one last time that the tenon is perfectly square in all directions: Next, the rounded corners at the end of the mortise are squared off with one of my favorite early 1900's Buck Bros chisels, like so: These are the tools that I'll use to gently "open-up" the mortise in order to generate a great fit: Next, I will insert the neck into the mortise to get an idea as to how much widening the mortise will require. Since all of the routes and machining are dead-on centered with the centerline of the body, I'll have to be very careful to preserve this as I work. At this point, the neck will not yet fit: Here I am using the sanding paddle to remove equal amounts from both walls of the mortise; I am careful to not only hold this tool correctly while working (not exactly as shown, I had to snap the pic while holding the tool in place!)...but to remove the same amount of material from both walls of the mortise, so as to ensure that my line-up with the centerline does not stray; I will count my strokes as I go. As I work, I check with a square to be certain that the walls are square with the floor of the mortise: Slowly but surely, the neck begins to fit into the mortise. It is important that there are no glue-filled gaps; the correct fit takes practice. If too tight, it may "seize" during the glue-up and not seat correctly; if too loose, a big loss of vibrational transfer occurs! The correct fit allows the guitar to be lifted by the neck and jiggled around with no clamps or glue holding the two parts together: Once I like the fit, it is time to check the neck angle. I use a slotted clamp block that allows a straight-edge to slip under it: Neck neck is clamped in place with the slotted block; the straight-edge is slipped underneath it, dead center along the middle of the fretboard; the height of the straightedge above the bridge position is checked; this one is correct. If it werent, the angle on the bottom of the tenon would be adjusted by hand: Once the angle has been checked, it is time to sand the top on either side of the fretboard, so that the top meets the neck/fretboard glue joint: Once that has been accomplished, a "dry fit" with the clamps and padded blocks is in order: The neck is now ready to be glued onto the body...and that is the moment that it becomes a real guitar!