Day 19

I've fallen behind in my blog-keeping duties.  Day nineteen is a few weeks behind me, and I have already done days 20 and 21- those will be up, shortly!

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 ;)

Days 16, 17, &18

It has been a while since I've updated the blog.  I'll condense a few days into one entry, since the days were very interrelated, and were spent doing a lot of the same processes, multiple times.  Here goes:

Days 16, 17 and 18 were mostly spent putting in linings for the top and the bottom of the guitar to be glued against, which add structural support to the guitar's body.  This included bending strips of basswood to the right shape, four times over.  I find bending to be challenging, sometimes- it definitely takes some getting used to.

Once the basswood linings were bent to the proper shape/form, I clamped two in at a time, without glue, to check the seams where the basswood met the rosewood.  Once everything looked good, and I was sure there were no gaps, I applied glue to each side of the 2 linings, and glued them into place. 

The clamping of 2 linings

I didn't glue them flush with the tops of the sides, but roughly 2.1mm below, to accommodate the top of the guitar.  I used nearly 50 clamps to keep them secure, and then waited about 45 minutes before removing the clamps to scrape away the glue squeeze-out.  I then did some planing, to make the sides nice and flush, and had to carve the linings, as well.  While the gluing surface stayed at its original width, the lower part of the linings were tapered down, to reduce mass, and create a pleasant aesthetic.

The profile of a lining

While the glue was drying, I added a shellac seal-coat to the exterior surface of the soundboard, with a cottonball wrapped in a small piece of cloth.  This was done to protect the wood from any potential blemishing or discoloration from darker sawdust that it might come into contact with, or any other contaminants, between the point of application and the time of adding the final finish.

Applying the shellac seal-coat to the soundboard

Next, I had to fit the top.  I had to centre it with the fingerboard and tail strip, and then I made lines indicating where the braces needed to be cut, as they were longer than they needed to be, as was expected.  I sawed a little bit off of each brace, and fit it again.  I did this a couple times, to get it right.  Since the braces were now just sitting on top of the linings, I had to carve out a little recession in each lining to allow the braces to sit within them.  I did this with a chisel.  Once everything was fit properly, I did a dry clamp of the top, with a jig that Ned had kicking around.  It is made of MDF (medium-density fibreboard) with a fibrous barrier on one side, that was probably 4 inches thick.  This ensured that a soft

The clamping/gluing of the soundboard to
the top linings

 surface was pressing against the top, so as not to damage it.  The fibre compressed as the clamps were applied, and everything looked pretty good.  Once it was confirmed that the fit was right, I applied glue, and clamped it into place.  I waited 45 minutes or so, then unclamped to do more glue scraping.  I also had to trim off the excess of the soundboard's perimeter, as there was a safety margin of wood left on, which was, at that point, safe to remove.  This was probably a centimeter or two around the whole soundboard- I used a whittling knife, and a plane, mostly.  The cedar was quite soft, so these tools proved to be effective.

Using the drill press to bore holes in the bridge

The bridge, after the shellac seal-coat

The second pair of linings had to be added- this step was done in the same manner as the top linings-  bending, gluing, clamping, scraping, and carving.  While these dried, I drilled the 6 holes in my bridge, where the strings were to be tied on- for this step, I used a drill press.  After the holes were bored, I used some precision tools to clean up the "exit wounds."  Finally, I did a shellac seal coat on the bridge, which made it look really nice.  It darkened the rosewood, and added a nice sheen.



Additional pictures:

Some nice-looking shavings from the plane-
basswood intertwined with Indian rosewood

 

Here's a nice shot of the guitar coming together- I especially
like the shape of the heel block.

Me and my masterpiece :)