I’m currently putting together a DuoSonic from parts and got to the point where I had to drill the holes in the body for the string-through ferrules. I remembered there was some kind of trick to make sure they all lined up nicely. If you just drill straight on through with an 1/8″ drill bit, that bit is thin enough to bend and wander and will often come out off-center from where it went in. Here’s an example of what I’m talking about.
So the trick involves first, using a template to drill the holes on the front side of the guitar, but only drilling them about halfway through the body. You then use the same size drill bit to make a hole in a piece of wood or MDF which is large enough to cover your drill press table. You also clamp it to the table, so that what you end up with is a 1/8″ hole directly in line with the drill in the press. You then put another 1/8″ drill, or dowel in this hole.
Flip your guitar over and place one of the holes you drilled on the top, onto this dowel. You now know that the drill press is perfectly lined up with the hole on the front and you can now drill the rest of the way through. You then leave the guitar centered on the pin, switch to the larger drill needed for the ferrules and drill those holes to the proper depth.
It worked perfectly and here’s the results on my DuoSonic:
That description of the process may be a bit hard to follow. It’s much simpler then it sounds. I was going to make a video, but as usual, a quick google reveals someone already did. So here’s Sully, of Sully’s guitar garage drilling holes and eating chile.
