fretting over details

I’ve sort of put the guitar on hold again over the past few weeks as I am wont to do when I accomplish some significant task and want to take a breath before I start the next one.

I’ve filled the space with a few Christmas presents I wanted to make for family and friends, some additions and alterations to my tool chest and general puttering around while I worked up the nerve to start the next phase: installing frets and gluing up the fretboard.

The breather between significant steps isn’t just about procrastination. It’s a way for me to process what I’ve done and what I’m about to do, and to let my brain work through the details. In this process I’m basically asking myself two questions:

  1. Am I happy with what I’ve done so far or do I need to go back and revisit something?
  2. What is the best way to go about what I’m going to do next?

On a project like this, if I can answer both of these questions honestly I feel like I’m ready to make shavings and sawdust. These two questions have more than once caused me to go back and fix something I wasn’t happy with, but they have also saved me a world of trouble in the long run. That is to say, they generally earn their keep and I think I’ll keep them around.

The last post I made on the guitar was about fitting the neck and getting it set correctly. I had a hard time grasping for the terminology to explain what I was working toward, but As Kieran helpfully added in the comments of that post, the lexicon I was looking for was “pitch, roll and yaw.” Basically, the three axes of alignment for the neck in relation to the body of the guitar. Once I was happy that I had aligned the neck I sat it aside for a time to ask the questions enumerated above.

Problem was, I couldn’t answer the first one affirmatively. I was happy that I had aligned the neck, but in the meantime I had been obliged to trim the tenon on the neck such that it no longer fit as snugly as I wanted. There was just enough play in the joint that I knew I wasn’t going to be happy and that led me to ask if I was going to be happy with the neck fit in general.

I wasn’t.

So today I changed the design. I hand cut the straight mortise into a dovetail shape.

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The slot also angles from wider at the front to the width of the old tenon at the back. And, because a dovetail slot needs a tail to fill it I was obliged to alter the tenon by gluing blocks to either side and trimming them down to match the slot in the body.

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The load of the joint is still reinforced by a bolt through the head block (which bears most of the tension on the neck) but the new hybrid dovetail mortise locks the joint into place much more securely.

I used mahogany off cuts to make the blocks and glued them on with a gel cyanoacrylate, then trimmed them to fit the dovetail slot.

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The gel sets slower, but it also wicks into the wood in a way that leads to a stronger joint. CA does have a lower shear strength than some glues, but again, I don’t think that will be an issue here as the bulk of the tension will be mitigated by the bolt, and unless someone is really interested in that process I’ll leave it at that. It’s not as pretty as I would like, but it’s strong and functional.

All of this did mean, however, that there was a fair amount of finiting to get everything back into place, but somehow doing it this second time went a lot faster.

Having re-set the neck where I want it I turned my attention to the fretboard. I had already radiused the fretboard to 16″ (Martin’s standard for these OOO sized guitars) and so it came to installing the frets. I took a scrap of wood from the bin and drilled holes into it to hold the frets so I could pre-cut them and keep them in order. My level of attention to detail (or lack thereof) here lead me to make 27 holes instead of 24, so I guess I’m ready to build that shred guitar next.

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In any case, I pre-cut the frets a little long, installed them with super glue and a couple of well placed blows with my soft face hammer. I had trouble with one fret because there was some debris hiding in the channel which lead to removing it and re-installing, but everything went pretty smoothly.

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I cut the ends flush with a pair of wire cutters that I had previously ground flat for this specific purpose. That took care of most of the work and my radius beam (loaded with 80 grit sandpaper) and mill file took care of the rest. I made sure the tang ends were all flush and then added a slight bevel to make them more comfortable to play.
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It was time to glue the fretboard to the neck. This seemed like a “no turning back” kind of operation so I went back to my reference sources, found what I needed to know, and had at it.

I am glad I went back to the Cumpiano and Natelson text because it suggested putting a flat shim along the back of the neck to avoid any clamp damage and to give a better clamping surface. That worked out great.

This isn’t rocket science, but it is woodworking, and a lot can still go wrong so I wanted to get it right. The primary thing you need to consider is keeping the fret board from drifting and keeping even pressure on it. I used two short roll pins that corresponded with divots in the back of the fretboard to align it so that when clamps were applied nothing would shift. Problem one solved.

Problem two was solved with my handy radius beam again (seriously, it’s earned it’s keep already). After applying glue to the 15th fret on the back of the fretboard I put the shim on the back of the neck, the radius beam on the top and started clamping from the head stock down every couple of inches until I had what seemed like a nice even glue line. I let that sit until I could clean the glue with a chisel and then left it in clamps overnight.

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This morning, I couldn’t resist a little test.

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