Sunday, January 27, 2013

Week 2, Top Bracing & Side Bending

What a week in the shop! The time is flying like saw dust, as we sand and chisel away!
The first step of the week was to radius the bottoms of the bracing sticks to match the desired radius of the top.  The bracing supports the guitar top from all of the pressure it will endure through years of string tension,
a notch is cut into the center of the main x braces so that they will fit together, and provide the strongest point of support.

The x brace is then glued onto the inside of the top using hot hide glue. Hot hide glue is a traditional glue used in instrument making for hundreds of years. The top is placed face down into a radius  dish, that has been machined out to the desired radius. The glue is applied to the brace sticks and they are pressed into place using a go-bar system. The go-bars are thin maple sticks that are bent between the bracing and a frame to apply even clamping pressure to the braces and push the top into the desired radius. Once the glue is painted onto the brace there is only 2 minutes to apply it, and place all the sticks, so you gotta move fast!

 The braces must remain clamped for 2 hours. The go-bars are then removed and the x brace is carved into the desired shape and profile. During this clamping time, the back pieces are jointed, glued, and clamped together.

 The brace shaping and carving is done with a chisel, finger plane, and sand paper.
There is a shape indicated on the plans and we are encouraged to try slight modifications, which will effect the tops final flexibility. Once all of the bracing is installed and shaped, David, will flex and tap the tops and make suggestions for more shaping.

Once the x braces were shaped, I took some time to lay out the sides of the guitar. I had to look at the side pieces and decide which sides of the boards would face out, and which edge would be the top and the back.
The two sides are then double stick taped together with the insides together and the outsides out. Then using a plexi glass template, I drew the profile of the sides and cut them out on a band saw.

 The next set of braces is glued to the top, and shaped. This set includes the upper and lower transverse braces, and the finger braces. They are glued into place using the same process as the x braces, and shaped the same way.

Now it is time to bend the sides! This is a slightly stress-full time in the build, because things can go perfectly, or horribly wrong! The wood is wet with water, wrapped in paper towel, then wrapped in tin foil, and laid on a heating blanket. It is pressed between two flexible pieces of spring steel. The whole " rib sandwich" is clamped loosely on a bending mold. The heat blanket is plugged in, and the "sandwich" is bent around the mold over a 3 minute time and left to set for 40 minutes. It is then re heated and left to set another 20 minutes. Then while still warm it is clamped into an outside mold shape and left over night.

The next day the sides are trimmed back to the ends of the outside mold and the mold is put together.
The mahogany neck and tail blocks will ad strength and support on the ends of the guitar. They are cut to length and the inside edges are beveled mainly for looks just in case anyone ever sees the inside of the box!

The final set of braces that go into the top are the upper transverse graft, the sound hole braces, and the bridge plate.  The graft and sound hole braces are thin strips of leftover top wood that are glued in for extra support. The bridge plate is made of maple and cut to fit into the lower x brace section. I chose maple for this piece because it will not color the sound of the top unlike rosewood ( the other common choice ) which would tend to add a bit of treble and re-verb to the overall tone of the guitar. Because my guitar is made of all mahogany ( a stiff hard wood ) it will already have enough treble built in. This set of braces was prepped and glued in in the final hour of Friday. They will be un-clamped first thing next week and the top will be mostly ready for the guitar!

Sunday, January 20, 2013

Jan 20th Week 1

Its been a busy week in the shop! Each morning we start our day with a short instructional lecture and discussion on our tasks for the day. Each step of the process is demonstrated by our instructor David Vincent as he builds his guitar for the year. Dave helps us see how each step effects the finished instrument.

The first step was to make plexi-glass templates for half of the top, and the neck profile. these templates will be used to make exact dimension parts from the wood.

The neck shape is not included in the printed plans because the guitar neck shape and size is a personal choice to the builder. Much of the play-ability and feel of the guitar comes from this part of the design. My neck measurements and shape comes primarily from a 1967 Martin O.M. that was brought in by a customer for Dave to repair.

We then used our half body template to trace onto a sheet of plywood for constructing a work board.
this work board will be come a sturdy FLAT surface for us to lay or work on and also serve as a holder when things are being glued together. It is draw out, cut out, and run through a thickness sander to make it as flat as possible.

We also draw out and make a  cork lined top template to rest our work on later to protect it from damage while we work,

While all this is going on we are also joining our top wood together! The top wood comes in two book-matched pieces about 9" wide. These pieces must be planed perfectly flat on one edge so that they can be glued together with a perfect seam. After the planing yields a seam which shows no light through when viewed with a light source under neath, it is placed on a jig, glued with hot hide glue and clamped up tight!

Once the top wood is glued up and dry it is removed from the jig and the glue seam is scraped to remove any glue that was squeezed out and has dried on the top and bottom. The joint is inspected to ensure it is sound, and the top wood is run through a thickness sander to bring it down to 3mm thick. Dave assist with this part of the build to ensure accuracy. We then use another jig and a 5 lb weight to test the deflection of the top under pressure. Dave helps us use these numbers and the tap tones of the wood to determine how much more thickness to remove if any to achieve the best top stiffness for the instrument being built.

The shape is then traced onto the top wood using the plexi template, and cut out with a 1/4" over-sized edge.
We then lay out the position of the sound hole and rosette using a compass and calipers. When we are certain the placement and measurements are right we use a laminate trim router to rout a slot for the rosette.
The rosette is glued in place and clamped and let to dry. When the glue is set the rosette is scraped flush to top wood and the sound hole is routed out.

It's starting to look like a guitar top now!
The inside of the top is then sanded smooth and the bracing pattern is drawn on using a pre-made plexi-glass template. At this point as you have seen a few photos back all the spruce brace wood has been rough cut and thickness sanded to the proper width and is ready to be radius, installed and carved.
Not bad for a few days work! Check in next week for more! Next week will be spent bracing the top and preparing the back and sides.

Monday, January 14, 2013

These parts will become an all Mahogany OM acoustic guitar in 6 short weeks!

Living the Dream

At almost thirty years old I have worked for half my life. This is an interesting thing to realize. Whats more, I have only recently ( in the past year ) begun to do work that I truly enjoy, and that actually matters to me. All I can ever remember wanting to do is make music. From an early age I have been fascinated with music and how people make it, use it, and react to it. I have sung since I could speak and have taught myself to play a variety of instruments. In my teens and early twenties, I played music in several groups, and came close to living the dream of playing for a living. I played all kinds of music with all kinds of people. I worked a slew of unimportant, uninteresting jobs for so many years just to support myself enough to have those brief amazing moments on stages of all sizes. During all this I never really gave much thought to my actual happiness. I didn't think about how sustainable my future happiness was. Then one day while working as a handyman it all hit me like a ton of bricks. I was 27 years old. I was not a famous rock star. I had been working for over 10 years with nothing to show, and I hated getting up and going to my cruddy job. It was time for a change.

All it took was one week of web searches, phone calls, and an entry test, to get me registered at a technical college where I could apply my love for music and my aptitude for mechanics. One week to start me on the path to a future in which I could be surrounded by music while making a decent living! I left my home state of Texas and moved 1600 miles to Minnesota, and after a year of filling my head with everything I could have ever imagined and more about band instrument repair, I found myself back in Texas making my living in a music store. I had done it! I was one of the few people out there who could say that I truly enjoyed my work. I was finally able to take pride in my work, knowing that the work I was doing was actually making a difference. Each instrument that I repaired gave a student or professional player the opportunity to play and sound their best, all while making a decent living and enjoying every minute of it.

After honing my skills in a busy shop repairing band instruments, I decided to return to school and expand my knowledge to include the repair and construction of one of my favorite instruments, the guitar. In just over another year I will be able to continue living my musical dreams. I will be able to truly "make" music happen. Building custom musical instruments and continuing to repair instruments of all kinds and calibers. It is a truly amazing feeling to wake up each day and enjoy what you do. If you have a dream follow it. You may be glad you did.