Saturday, April 2, 2011

A Night In The Box

I'd like to start by issuing a Jumbo sized thank you to Derek from Bourgeois Guitars for coming into our shop as a guest lecturer. Derek is a graduate of the Guitar Repair Program at Southeast Tech from a few years back and he now works in a shop that is producing world class instruments. Bourgeois builds some of the finest instruments that exist on the planet and Derek is largely responsible for voicing the tops of these guitars. The process of voicing involves assessing a particular top for stiffness and tap tone and then adjusting the shape of the braces to most flatter those qualities. You can find the Bourgeois website here. If you are interested in learning more about voicing acoustic instruments, Dana Bourgeois has kindly posted some outstanding articles on the topic. Look for "Tonewoods & Voicing" on the Pantheon home page.

Photobucket

Brace work. Not orthodontics per se, but we are talking about arranging mass to achieve a certain aural and tactile aesthetic. This is the aspect of guitar building that typifies the quest for TONE. There is no right or wrong way to do it and conversations about it can quickly veer into the Twilight Zone. That is part of the fun that keeps builders coming back for more. Derek came to us from the shop in Maine to help us understand and execute the process of changing a brace from adequate to "perfected". Take a good look at the braces in the above picture, then examine them again the next time they pop up (Ha ha. A bad luthier joke there.)

Moving on to other progress, the book matched back of the guitar is jointed and glued using the same method used for the top, which has appeared in another post. The back is then braced, but in a very different fashion. We glue most of the braces in using a "Go-bar deck". It's a simple concept, but versatile and effective.

Photobucket


Photobucket

Very different bracing. Right? It goes like this. The top of the guitar acts like our vocal cords. It gives the guitar the fundamental qualities of "voice". The bracing pattern and carving are like singing lessons. Good brace carving takes a guitar from sounding good to sounding great. The guitar's back, on the other hand, supplies some core resonance and reflectivity. It, allied with the sides, is the concert hall in which the vocalist performs. So the brace pattern and shaping is less critical. Basically, they need to be just strong enough to support the structure without bogging down the resonance.

The next big job is bending the sides. Prior to the lecture, this seemed an intimidating process. There is a great deal of talk about certain tonewoods being "difficult to bend" or "prone to cracking" and once you get to the point of actually bending the wood, the fear is built in. The lecture/demo allayed ours and made the process more pedestrian. Still, we are taking some very expensive wood, sanding it down to an even thickness of around 2 millimeters(!) and then bending crazy S curves into it. Here's the secret... steam and a very well made bending form. The sides are moistened with water, wrapped in a wet paper towel and sealed tin foil, then sandwiched with a heat blanket and thin spring steel. The blanket reaches about 500 degrees in 45 seconds or so and super heats the water to create fast steam.

Photobucket

Three minutes later...

Photobucket

We then pop the bent sides into an outside mold to prevent reversion and to provide protection and strength needed for the next processes, beginning with gluing in the head and tail blocks.

Photobucket

And then kerfing...

Photobucket

The kerfing adds additional strength and provides a greater surface area to glue the top to the sides. It also provides leverage for the braces to work against. This shot is pre-cleanup. Any glue squeeze out has to be cleaned up at some point if you want to produce a classy instrument.

Photobucket

After cutting the notches for the braces to fit into, the top is glued to the sides. There is great excitement in coming to this play in the game because the individual parts really start to look like a guitar.

Photobucket

Here are those "perfected" braces I spoke of...

Photobucket

And she spent her first night in the new flat. Sweet dreams...

Photobucket

We are taking big steps. Check back soon to see the rapid gains.

1 comment:

  1. Freaking brilliant Fred! I get so excited seeing the progress and I don't even PLAY. Alan does and he loves to see you moving on. Lots of Love!

    ReplyDelete