I spent this day doing what was necessary to aid in getting the back of the guitar attached. I did many of the same steps for the front of the guitar. I began by placing the back where it would go, using a pencil to mark where the braces intersected the lining, then starting the trimming process. I used a saw and chisel to respectively cut and pry the excess off of each brace's tips. Once the braces were trimmed, I carved shallow notches in the linings, to test fit the brace intersection. After I confirmed that the notches were correctly placed, I continued the process, and made them as deep as each brace was thick.
Now, the main difference between applying the soundboard and the back is that the back has a bit of a contour- it isn't completely flat. This means that the butt of the guitar sits closer to the soundboard than the top of the back does. To explain this concept better, think of the guitar laying on its top, with the soundhole facing down- the depth from the bottom to the top of the guitar (that is, the depth of the side), is greater, where the heel block is, than where the bottom/butt/tail of the guitar is. The reason for this lies in the theory of sound propagation- it is better to have curves to project the sound, than a flat surface, that won't aid in deflecting the waves- think of how a speaker is shaped like a cone, instead of a disk, or how an amphitheater has a curved back, opposed to a flat one.
That being said, I had to use a plane to reduce the height of the sides at certain points of the guitar, to accommodate this curvature. This was a bit of a finicky process, where I had to take off a bit, and test-fit, many times over. I also had to do this at the heel block, using a plane to taper the point on the heel block, giving it a very slight slope, which was going down, towards the neck. After all of this was done, I was ready to dry-clamp the back on.
After the dry-clamp was confirmed, and the seal looked flush all the way around, the glue was put onto the lining, and in the notches, and the back was put back on, and clamped into place.
After giving it about 45 minutes to an hour of drying time, I removed the clamps, and had to do some glue scraping, on the inside of the guitar- THIS PART WAS NOT FUN. I have pretty large hands, and without that disadvantage (in this scenario, anyway), it's not fun contorting your hand inside of a guitar, where there is low clearance, and even less clearance where the braces protrude. This took me at least a half-hour...
The last step of the day was to trim off the excess wood around the perimeter of the back, as there was now about an inch of extra wood all around it. Indian rosewood is a hard wood, while cedar is a softer one, so I wasn't able to fully utilize the ease of a whittling knife to do this, as I had with the soundboard. Instead, I used a saw to get the bulk of of off, cutting what geometrically, on a circle, would be chords. For the remainder, I believe I used the whittling knife a bit, but I definitely had to put a bit more muscle into it than I did with the soundboard. And that was it.
After all was said and done, I had a guitar that had a front and a back, and I was able to tap the guitar at various points and hear different tones! It was great. The guitar was like a drum! It's going to sound fantastic, once it is all strung up ;)
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