I’ve been buying and selling guitars for 54 years. I’ve been building guitars for 2 years. The resulting guitar shaped objects are approaching mediocrity. I have no prior training with any kind of tools or woodworking. Like most beginners, I’ve been buying the occasional odd tool, mostly at garage sales and the like. There are a few of them that I use all the time that may not be in your usual luthier’s toolbox.
I hate to measure. I’m just not very good at it. One of my most often used items is a “parallel set.” It’s basically rectangular pieces of steel in pairs that range in size from about 1/2” up to about 2” wide. They are all the same length, about 7”. There are about 10 pairs. One thing I do with them is place one (the size depends on the instrument) along the last fret, to draw a line across the fretboard that represents the end of the board. That’s where I cut it off.
Another use is placing/gluing braces on the top and the back. On the back, I glue one brace down in the right place, then use the parallel set to place the remaining ones. Lo and behold, they end up parallel to the first. It’s great for laying out the tones bars and the finger braces on the top so they are parallel as well. I just remove them and wipe any glue residue off after the braces are clamped in place. I also use them to ensure that the back braces are perpendicular to the interior central back strip.
Here’s another one — if you look at the picture, you can see exactly what this is: it’s a carpenter’s adjustable square with two of the “handles” put on the “ruler” part in opposite directions. I place one edge against the last fret, and the other edge against the front edge of the bridge when I’m figuring out the correct placement; it ensures that they are parallel. No measuring.
I’m certainly not the first to do this. It got old real fast installing frets on my hands and knees on my concrete deck. I do not want to combine yoga and guitar building. So I bought this Mojave Granite Surface Block on craigslist for about 100 bucks, and put it on my outdoor work bench. Now I can clamp the fretboard down while I’m fretting it, which helps keep it flat, and standing up is so much easier than kneeling on the concrete…