Class 1 (Saturday Lab)

Saturday morning class is a combined class of the classical and steel guitar making courses. There were several TA's on hand which was nice. The objective today was to build the shell of the acoustic guitar. Our sides would be made out of Brazilian Rosewood and we were lucky enough to have very distinctive coloring in our sides. There was a very noticeable red streak running through the middle of ours which turned to a purple.

In order to build the sides we have to bend the sides into the traditional S shape that an acoustic guitar has. In order bend the sides we needed to attach them together to make the frame. We attach the sides what is called a block. There is one for the neck and one for heel (bottom). The dimensions are 70mm wide 32mm thick X around 90mm tall. I had purchased a 8x8x2 block of mahongany the day before so I set off to find a T.A. to get checked off on the band saw. Cian began the work of sanding down the sides. We had planed it on Thursday night (First night of class) in the Safety Planer. The planer simply reduces the width of the board but does not leave it very smooth. Also if you weren't quick enough in pulling the board through the planer it would start to burn so we had a couple of ring marks that we needed to sand off also. After planning it down to 2.4 mm the board was still rather stiff. There were technical difficulties with the sander but once operational, the side was sanded several times until the board was much flexible

Once the side was sanded we had to do two things before we could bend them. We had to locate the beginning and the end of the side and mark them. You can see the white marks toward the end of the board. We had to mark the center point as well. Know that we knew which side was going to be external facing and which end was going to the neck or the heel of the guitar, we needed to adjust for the curvature of the top of the guitar. We found out that the acoustic body actually tapers slightly as it approaches the neck. Funny after all these years of holding an acoustic I never really knew that. To accomondate for the tapering the sides had to have a radius to the side board as it moves toward the neck. You can plainly see the tapering of the board in the above photo.

Now we turned out attention to constructing the blocks. Once we had cut and sanded the blocks to their specified size, we needed to adjust the bottom heel to the curavature of the bottom of the guitar. This was done by drawing the radius on the block and using a planer shave the corners until it fit snugly against the bottom. The neck did not need this adjustment, but the external portion (facing the sound hole) was planed for cosmetic reasons. Next time you have an acoustic look in the sound hole and you can plainly see the block looking back at you. As we were told, the insides tell as much about your ability as a craftsman as does the inside.

Now that we knew which side was up it was time to bend the sides. Bending the sides is done using a press. The board is thoroughly wet down using a spray bottle then placed in between two metal sheets. A "warming" blanket is place on top. This blanket rapidly heats up to about 500 degress. As it increased in heat we slid down the guides to hold everything in place. There are three guides, one on the bottom, one on the waist (middle) and one at the neck.

In the photo above, Jim (T.A.) shows Cian how the mold is put together. Once the sides are bent, they are placed in the mold until a top and bottom are attached to the sides, several weeks from now...

There is a risk of breaking the sides during this process. If this does happen (and it does), then super glue could be used to repair the break. Fortunately no ones has broken yet.

Notice in this picture the top guide has already been pressed into the waist. I am rolling the bottom guide down to bend the bottom of the guitar. Cian will do the neck as soon as the bottom is complete.

That's one side, now we turn off the blanket which is at about 500 degrees. We let it cool to room temperature. Once it is cool it will be placed in the mold and attached to the neck and heel blocks making the outline complete. That will have to wait until next Thursday since we did not have time to complete it.