Building An Acoustic Guitar – The Sides

It’s finally time to start constructing this guitar. After all the initial lumber prep has been done and I’ve built a few tools that I’ll need it is time!

After some thought I decided to start with the body of the guitar instead of the neck. While the neck is a bit intimidating I figured the sides, particularly bending them would be my biggest hurdle in this project. I like to get the hard stuff out of the way so that made my decision to begin working on the guitar’s body an easy one.

I began by making a template of the shape of the sides from the plans I purchased. From there I could use the template to transfer the shape to my stock for the sides. Screen Shot 2015-06-23 at 9.57.28 PMI then took the stock to my bandsaw and cut them out. I stayed about 1/8″ outside of my lines though. This allows me to attach the template back to the roughly cut out side and use a pattern routing bit at my router table to make the side an exact copy of the template. I did this for both of the side pieces.  At this point the sides are still too long. They will be trimmed to their final length after they are bent.

Next I needed to transfer the indicator lines from the template to the side. Screen Shot 2015-06-23 at 9.59.22 PMThese marks indicate the length of the sides as well as the places the bends will be made.

With all of the layout complete its time to bend them. I used my shop made bending iron for the job. I found that spraying the area of the side to be bent with water then immediately applying the side to the iron worked best for me. It took a little while for me to figure out the proper amount of pressure to use while bending as well as the rocking technique I used. I found that I was applying a significant amount of pressure. More than I had anticipated prior to starting the bending process. At a certain point you can actually feel the wood loosen up and accept its new shape. I also discovered that rocking the piece back and forth and around the iron worked well. This meant that I put pressure on the sides of the iron as well as straight down. It seemed to produce a cleaner bend as opposed to sliding the wood over the iron and only applying pressure straight down.

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Frequently during the bending process I took my piece to the mold to compare my bend to the shape of the mold. I found it was pretty easy to get the wood to bend nearly exactly to the shape of the mold.

 I did burn the sides a little bit. I’m not sure if this is a result of letting the wood become too dry or leaving it on the iron for too long. Either way the burning is minor and I’m sure I can sand and scrap it out later on in the project.

Once the sides are bent I took them to my bandsaw and trimmed them to their final length. With the sides having the proper bends and trimmed to length it’s time to put them in the mold and use the spreaders to hold them tight its sides.

Next I needed to make the heel and tail blocks for the guitar. These get glued to the inside of the guitar and are what hold the two halves of the guitar’s sides together. I referenced my plans and cut the blocks from mahogany. All of the internal structure will be from mahogany. With the blocks made they can be glued in place.


Screen Shot 2015-06-23 at 10.09.59 PMAfter the glue dries on the heel and tail blocks it’s time to glue the kerfing to the inside of the guitar. I didn’t show it in the video but I wetted the kerfing and clamped it to the outside of the guitar to help it take the proper shape. Reversed kerfing, the kind I made, has a tendency to break more often than traditional kerfing so I figured pre-shaping it couldn’t hurt. With the water dry and the kerfing roughly bent I was able to glue the strips on the sides of the guitar without issue. I did attach them slightly proud of the guitar sides. This way I could come back later and trim the kerfing and the sides flush with a block plane.

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The final step in the construction of the sides of the guitar is to install the wedge where to side pieces come together on the bottom of the guitar. I always thought this wedge was purely decorative. Now I know it is put in to hide that the joint where the sides come together may not have been absolutely perfect. I didn’t attempt to make mine perfect because I knew I’d be putting the wedge there but I can imagine a luthier a long time ago installing the wedge after discovering that his side pieces didn’t come together as perfectly as he or she would have liked. Likewise the joint where the sides come together at the neck doesn’t need to be perfect either because it’ll be cut away when the joinery for the neck is cut.

To install the wedge I found a scrap of mahogany, to contrast the walnut sides and cut a quick wedge shape from it. I then used the wedge to layout where I needed to cut to insert it. I started by sawing on my layout lines down to the tail block. I then chiseled out the wood between the cut marks. Once the wedge fit in properly I glued it in and flushed it up the to rest of the guitar.

   I’m really happy with how well this part of the process turned out. I feared that this might be the demise of the whole build. It wasn’t though and I could t be happier with how it turned out.

Next up is to start working on the top and back of the guitar!

Thanks for reading.

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