How to Use the Neck Templates to Carve a neck
Below are the instructions on how to use a Luthier Suppliers Neck Template to carve an acoustic guitar neck. The videos below were taken from a class at the Colorado School of Lutherie
First you will need to get your fretboard ready by first thicknessing it to standard dimensions of around 1/4". Go ahead and cut the fret slots. You should radius your fretboard at the nut and last fret using the same radius number that is noted on the gauge.
Before you cut the fretboard taper use a digital caliper with the Neck Contour Gauge to measure the width at the nut and at the last fret. Make sure you take the measurement directly over the fret slot. Mark these numbers on your fret board and use a ruler to connect the marks.
Cut out the taper of the fretboard and check that your fingerboard width matches the appropriate measurements (the cut-outs are deliberately made slightly large so as to more easily check the fingerboard radius).
At this point the neck will have already had the peghead glued and thicknessed, peghead veneer glued, the heel glued, the truss rod installed, the neck attached to the body by bolts or dove tail joint, then the fretboard glued to the neck blank. There are many steps in this process that are not covered by this tutorial.
Go ahead and install the frets while the back of the neck is still flat. This eases the pressing of the frets, or hammering of the frets because you do not have to worry about the neck rolling on you, or damaging the back of the neck.
With the neck ready to start carving, create a quick jig to keep the neck stable while carving. It is made up of a 3/4" thick piece of plywood that is 24" long x 3". Clamp or bolt to your bench top, and a place a rubber router pad between the frets and the board to protect the frets.
Next you want to remove the extra wood on either side of the fretboard. You can use a chisel or rasp to get it down flush with the fretboard. As you get closer to the fretboard you can use a cabinet scraper or sanding blocks.
Create a template for the heel shape and make a cut out for the truss rod. This small jig is made out of 1/4" hardboard, and cut to any shape you want. Trace this on to your heel, then cut a little outside of the line.
Next you want to cut off the excess outside of the line that you drew in the previous step. You can use a saw or chisels to get it down, then use a rasp as shown below. Draw a shape on the end cap to whatever you choose, but be sure to leave it long enough for the bolt inserts. Bolt inserts are usually 1/2" to make it slightly longer than that. Trace it on the cap, then cut and rasp around it.
Next, go ahead and finish rough shaping the heel.
In the next step you will start to carve the thickness and curvature just in front of the heel, around the 10th fret. Refer to the template for the exact location to start carving. Most steel string guitars are marked on the template at the 10th fret. So directly under the 10th fret, use a rough rasp or a microplane to get the right thickness and curvature. Continue checking the curvature against the template as shown in the videos and pictures below. But be sure to leave about 1mm or 1/32" oversized. Final sanding will take care of this later.
Next you will do the same step at the 1st fret that you just did at the 10th fret. You should also start to transition the neck into the peghead as you do this.
At this point you should have the area in front of the heel and the area under the 1st fret thicknessed and contoured to within 40 thousandths of an inch. You will have a large lumpy area in between these 2 points. The next step is to remove the material between the 2 points using a spoke shave(or any other tool to quickly remove material). As you get closer to the final dimension, switch to a rasp or scraper.
Next you will use a small straight edge or ruler to find lumps in the neck that need to be evened out throughout the curve and up and down the neck.
The final step is to use sandpaper to smooth and blend any marks left by the rasp or microplane. Use 80 or 100 grit for this step to get even closer to the final thickness at the 1st and 10th fret, then finish with 220 grit. At this point you should have a carved neck. Congratulations!