Wednesday, June 25, 2014

Some Trouble on the Build My Guitar Front!

Build My Guitar

So here it hangs in all its glory, my guitar with a single coat of gun oil, the first of a bunch, to bring out its fabulous figuring. I would be lying were I to say I am calm about this, but it doesn't pay to get too excited, a point on which I got an important lesson on Tuesday, when I went to see Bruce Roper at his luthier's shop off Lincoln Avenue and got an unhappy surprise.

If you were living in a bubble you might not have had any trouble with humidity these past two weeks. I do not. In Pennsylvania, it was so humid it was impossible to breath even in the woods. Apparently, the same problem was at work here in Chicago. You can't see it and I'm not going to show it because it may be a problem that will solve itself, but the back of this spectacular guitar now looks a little like the surface of Lake Michigan. Wavy in a bad way. I can explain how that happened, but I am also convinced the problem will solve itself over the next couple of years. (Owning great guitars is a long-term proposition.)

How it happens.

Wood is porous, and depending on the type, some is more porous than others. That is why people who build instruments pay a lot of attention to relative humidity and the levels of humidity in the wood they are shaping. Guitars like it in the 50 to 55 percent humidity range. Bad things start to happen when humidity drops below that number, and other kinds of bad things happen when it gets above it.

Drop too far into the dry zone and the wood shrinks somewhat dramatically, sometimes cracking surfaces or pulling them away from braces. Frets, the metal strips across the fingerboard that actually stop the string so it can vibrate and make its sound, seem to grow. In reality, this is one of those, "No, fool, the sun's not going down, the horizon is coming up" problems. If frets are sticking out, it means the fingerboard is shrinking from dryness.

Bob Taylor (That's right of that Taylor) wrote a recent article and included this picture of a fretboard that has shrunk from dryness.

Doesn't seem like much of a problem, does it. Try to play a guitar like that and it feels like someone is pushing tiny chisels into your hands. Again, the problem is the fingerboard shrinking, not the fret. You can fix this. But this is not my problem.

I can find no pictures of what happens when there is too much relative humidity. So I will explain it. Just as wood shrinks in dryness, it expands when it gets wet. Not much of a problem for a piece of wood just sitting there, but the back on a guitar is glued in place in so many different ways it's pointless to list them. It's a solid thing if its done well.

The problem is the solid thing has no where to go if humidity comes to visit. In most cases, this is not a problem. Guitars adjust themselves. But in some cases, when the humidity goes up far and fast, the instrument can't do anything but create bumps as the swelling wood strains against the glue points. A little of that is what happened  on the back of my guitar.

Bruce seems mortified. It's not that his shop is sopping wet. Mine is the only guitar that has had this problem over the past couple of weeks, and Bruce has lots of guitars at lots of stages in his shop. It was such a wonderful thing just a few weeks ago. Now it has some bumps. I doubt anyone will ever see them but me and I view them as a small crisis in what is a relatively long journey. There is probably an upside here in a couple of years. When I put this instrument in my house, which has air in the summer (We have done well!) and the right kind of heat in the winter, the bumps will most likely go away.

Too much time on bumps. On to the neck thing. That's right, the neck thing. We're building the neck now.

And I do mean building.

Measuring for the fingerboard and headstock

The bald neck with its tension rod
Cutting to size
This part of the job is a little like building a bridge (Yes, I know, there is a bridge, but that's later). Bruce's neck bolts on in two directions. No glue at all. That means it is easy to get off if you have to remove it for repairs. This is the design he has settled on after 20 years or so of struggling with necks glued into place with everything from old horse hide glues to epoxy. It's much easier, although less traditional, to just bolt them on in a way that works. Bruce's is a way that works. He will have horizontal bolts going into the block at the top of the guitar, and vertical bolts under the fingerboard.

But first, we had to get everything about the neck ready for the big glue up!

Putting the frets on the fingerboard was pretty interesting. The frets have a 16 inch curve to them, to match the 16 inch radius curve of the neck. Bruce uses a couple of tools to put them in place. On is a simple fret cutter. The second is a little gizmo he invented that gently rocks a 16 inch curve in the fret so it will fit well.

Rocking the curve into a fret
Then he puts the fret in place and taps it a bit with a fret hammer just to get it going. Then he uses a drill press with a special jig that also has a 16 inch radius curve to push the fret into the slot. The frets have little tangs to hold them in place, but Bruce uses glue, too.

It takes about an hour to get all the frets into the neck for my guitar. When it's completed, it looks like this:

Frets in place on a fingerboard
I'm thinking we are close to a finish on this guitar, and that is exciting for me. I can't wait to hear it. We tap it each time I visit. It sounds bright and clear. That could be very nice. But we won't know until it's finished. My guess would be mid-July.

Until that time, it's all happening right here at

Tell your friends. Tell your inlaws. Tell your parents. And so on. See you later!