Step 9: The Binding
I routed the channel for the binding using a table router. I used a router bit with a bearing that rides on the mandolin's sides for a consistent offset. This method was very reliable, accurate and took no time to set up. I used a combination of two different bits to achieve the desired offset. I took the bearing from a 1/4 inch flush cut bit and the cutter from a 3/8ths inch bit which gave me a 1/16ths inch wide channel.
At the neck on the top side, I stopped just shy of the heel and then cleaned up the corner with a chisel. I went a bit too far at the neck on the back side and marked up the underside of the neck. These gouges luckily cleaned up of with a bit of recarving at the base of the neck. It really is only necessary to route to the heel on both the top and back since the button is going go there anyway.
Tail Binding Slot
I cut the slot for the tail trim that would cover the joint between the two halves of the sides on the table saw. I used a rig that was quickly improvised using a piece of plywood screwed onto a miter gauge and then clamped directly to the mandolin's body. One pass on the table saw was enough to make the 1/8th inch wide slot.
Unlike most buttons I've seen, this one extends beyond the neck's end and over the top of the sides. This is due to the very short heel section of the neck. The button looked strangely proportioned to me when I layed it out so it would only cover the top of the neck. I used chisels freehand to remove the wood from the button area and to smooth and flatten the final surface to accept the button.
Bending the Binding
I used the same rig to bend the binding as I used to bend the sides. I secured the binding to the body with large rubber bands while they dried and cooled.
Gluing on the Binding
I first had to carefully cut the top binding to length so that the ends would fit snugly flow into the neck. I left the back a bit long to be trimmed to size later. To secure the binding while the glue dried I used masking tape. This was very easy to do with only one person. It took a lot of tape and some care in how and how tightly the tape was secured so that the binding would be held firmly in place while drying. I added a bunch of rubber bands to the heel area where the binding was especially stubborn.
Trimming the Binding
Once the glue was dry, I planed down the top edge with a thumb plane. I sanded down the overhang on the sides using a spindle sander. Being careful to not take off too much material, I cut off the excess from the button ends of the binding for a tight fit with the button.
Using a paper template positioned with the binding as a guide, I drilled holes for the tailpiece pins. With the body clamped down securely on drill press, I drilled the four holes at least an inch deep each using an 1/8th inch brad point bit.
Attaching the Button
I glued on the oversized rosewood button using wood glue. I made the button by cutting a piece of rosewood slightly thick, then slowly sanded the profile using the actual heel of the neck as a guide. I could have made the button much closer to the correct size as it was very difficlut to par down without hurting the rest of the neck once glued in place.
Installing the Tail Binding
The tail end binding was glued with wood glue and held in place with masking tape to dry. I sanded the excess with the spindle sander again.