Bending the Sides

Now it is on to the sides of the guitar. The sides that I purchased are also Koa. And the best part about these sides are that they actually out of the same board as the top and back so they match perfectly.

The first thing that was done was to thickness them. They are at approximately 2.5 mm thick but will be a little thinner once we complete final sanding.

What we do next is to start the bending process. This is accomplished one side at a time. First, I had to determine the "show" side of the sides and then determine what would be the butt of the guitar (the point opposite of the neck). Then we get them prepared for bending. Bending is accomplished through the use of a very nice (albeit expensive) jig.

This is accomplished through the use of heat and steam. The sides are sprayed down with water and then placed in aluminum foil (I didn't catch any pictures of this process, but I don't think it was all that necessary). Then we set up the bending machine. The bending machine has two pieces of metal alloy that cover both sides of the guitar, and a heating blanket that can "cook" the wood to approximately 500 degrees Fahrenheit. It also has a few different clamps that can be seen in the picture to the right at the waist and at both of the ends of the guitar.

The funny thing about the sides that I purchased was that there was no extra wood with it. We had one shot to make this perfect as we didn't want make any mistakes and make the need for purchasing any other sides.

After about 20 minutes of cooking the wood and another 20 or so minutes of the sides sitting in the forms, the sides are all ready to come out.

When they came out of the foil, we saw a little greenish glow to them (pictured left). This is due to the oils in the wood that have been steamed out. Not to worry, this color will disappear after sanding a bit.

Additionally, there was some spring back when the sides came out, meaning that I will have to hand bend the sides the rest of the way using a bending iron - but we will get to that.

Just to get a look at how the sides will appear when finished, you can see a picture of the sides will a little Naptha on it (the back is also shown in the lower left hand corner). You can see that there is a lot of figure in the wood still and the back and sides will definitely match when all is said and done.

Finally, after both sides have been bent, I use some spring clamps and a piece of masking tape to hold them in place over night. This is done because the sides could be slightly wet still and we don't want to worry about any more spring back.

After the sides sit overnight as pictured left, they are ready for some final bending. and getting them ready for kerfing.

In the picture on the right, you can see the rounded bending iron. This metal piece heats the wood again so that we can bend the sides to the right dimensions. The sides are soaked again with water and then placed on the iron with some pressure around the area that needs to be bent. For this guitar, the waist had some spring back, so that was my first goal. Then, each the upper and lower bout is just given a once over so that they are perfect.

The sides are then placed in negative forms so that they will be in the exact right position. Clamps are then placed at the upper and lower bout, and also at the ends of the sides. Some sand paper is used to clean up the greenish color of the wood.

It is now time to get the kerfing set up. Kerfing is the wood that is glued between the back or top and the sides of the guitar. For this guitar, I am using spruce triangles, but there are many different types of kerfing that can be used.

The kerfing is slotted so that the wood can be wrapped around the inside of the guitar. Glue is applied to the kerfing and then is clamped down using spring clamps. As you can see a lot of spring clamps are used in this process in order to keep the the pressure consistent throughout.

When the glue is dried, the sides are strengthened so much that there is limited spring back when released from the forms.

After about an hour, the spring clamps are taken off the kerfing. The sides will sit overnight in the forms so that the glue can dry.

The next course of action will be to glue the sides to the top and neck by a process called tantalloning. This process will be showed in the next week or so. Enjoy!

Continuing on the Back

Now it is time to brace the back of the guitar. This is mainly done to strengthen the very thin wood. For the parlor guitar, I will be using three different braces. Many guitars have four. However, since this guitar is extremely small, it is only necessary to use three.

First, I built the braces and flattened them out. This wood was from the same stock as the neck and was spindle sanded down to make the scallops. Additionally, the base of the braces were flattened on the granite block (with a piece of sand paper).

The process of gluing up the braces is very similar to that of the top. However, since these braces will be visible through the sound hole, I decided put on some tape to limit the amount of excess glue that gets on the back.

Once everything was all set, Titebond was applied to the surface of the braces and then placed in the correct area of the back. It was then placed in the Go-deck and the rods were place about an half an inch apart. These braces were left in the deck for about an hour.

Next, it was time to make the center reinforcement strip. This strip is used in order to strengthen the glue joint between the two book-matched sides.

As before, some masking tape was used in order to limit them amount glue on the wood that will be visible.

Again, the Go-deck was used in order to put the correct amount of pressure on the braces. In the picture to the left, you can see a few different things. First, you can see that the braces have been shaved down in order to reduce the amount of wood that is on them. Additionally, each piece of the back strip, you can see has been numbered in order to make sure that I do not mess up the placement of the pieces.

Again after another hour or so, the back is pretty much all set and ready to go. The only thing that needs to be done is some final sanding. That will be accomplished prior to the glue up of the back to the sides. That will come a little later.

As you may notice, the back is much simpler when compared to the top. Next on the docket will be bending the sides.

Working on the Headstock

Next, I began working on the headstock. For this guitar, I choose to use a slotted headstock as it looks a bit different than most guitars and it is more of the classic style of a parlor guitar.

The first thing I did was determine the size of the bushings for the Gotoh tuners that I purchased. Additionally, I had to determine the depth of the cut that we had to make. This was done in order to make sure that there were no excess holes in the slots.

After doing all the math, it was time to make the cuts. It is definitely a kind of stressful time, as you have one shot to make it work. However, all that work, I successfully was able to make the cuts perfectly. On the picture to the left, you can see the pencil marks that I used to determine the placement of the drill press. Additionally, you can see one of the tuners that has been placed to make sure that they will fit perfectly (and they did!)

So it is at this time that we start to make the slots in the headstock. To do this, I first determine the height and length of the slots and then use the drill press again to cut out as much of the waste as possible.

Using the drill press is just a quick way to get out the waste. It could be done all by chisels, rasps, and files. But this made my life a heck of a lot easier.

Then I began the long process of getting rid of the rest of the excess wood. You can see in the picture to the left that I placed the headstock in the vice so that the lowest point of the drill cuts. I the used a 1/4" chisel to continue to cut the excess out. This was a relatively time consuming process but once it was complete, you can see some great looking slots for a slotted headstock.

There was one issue, I had decided that I did not want to have the slots be rounded over at the top and the bottom. Therefore, I had to continue to chisel out the slot in order to make it flat.

This was completed using a 3/8" chisel and some brute force. Basically, I would make small cuts in to the wood and then knock them out. It took some time but finally the four rounded humps were flat.

Lastly, I had to file the slots so that each side was completely flat. The picture to the left shows the finished product to this point.

There was one last thing that needed to be done was to make the ramps in the slots. The reason that you must have these are to let the strings be unimpeded when they are tight. This was accomplished through the use of yet another chisel and files.

By the time that this process was complete, a nice white line was able to be seen at the bottom of the slot which really made the slots pop (or at least in my eyes - see for yourself). Finally after a long process, the neck and the headstock are set to be glued up to the top of the guitar.

First, a small notch had to be cut out of the heel in the neck. This is to make it so the top and the neck were flush. Then, I had to make sure the top and the neck lined up perfectly. This is a rather stressful glue-up because if you mess this one up, the neck will have an angle which will cause issues with intonation.

To do this, center lines are drawn on each surface so that we can really line them up. Also, a piece of flat MDF has a line drawn on it so that we have a way to set everything up. Glue is then applied to both the neck and the inside of the top of the guitar.

Then the neck is placed on the top and lined up perfectly. After about five minutes of holding the neck and top in place, a large granite block is placed on the heel of the guitar to apply pressure. Then it is a waiting game. After a few hours the glue is all dried and I can finally see what I have accomplished.

Take a look at the picture on the right. You can see that the top and neck are completely straight and there is no angle. Though stressful, another perfect glue up.

Starting the back

So I began working on the back of this guitar when I started working on the top. That is, I glued up the two bookmatched sides in order to set up the back plate. However, since that time, it was just set aside awaiting its time to shine. During the glue up phase of the neck, I was able to surface the wood, so that it would be set to work with. I left this a little proud because I knew that there was going to be a decorative strip added into the back, called the backstrip. There is no real reason for this piece of wood to be added. Other than the fact that it looks nice. Some people leave it off altogether. However, for this guitar, I thought it would be a good addition. You can see in the photo to the right that the back is surfaced and the piece of Indian rosewood is laid on top. It has some white veneer on each side, to offset it from the Koa.

The first thing to do is to cut a 1/4" channel where the strip will be inlaid. This is done with a router. We are very careful not to let the router wonder. Additionally, we had to make sure that the router depth was correct, so that we would not completely cut through the back.

First, I marked a center line on the back, and then placed a piece of plywood on the back using double stick tape. I carefully place this down so that we offset the router bit perfectly. One pass with the router and we are ready for glue up. We have to be very careful with the back at this time, as there is a possibility of the back breaking from having the channel added to it.

To glue this up, we take some white glue, and put it in the channel. I spread the glue around the channel and then place the strip into the wood. We put as much pressure with our fingers as possible. We could use the go-deck at this time if we wanted. But since the strip fit perfectly, there was no need to do this.

After we let this sit for a few hours, so the glue dries. I am ready to resurface the back again. First, I use a hand plane and take some shavings off the rosewood. Once it is pretty close to flush, I start using a sanding block to take away the rest of the material and also some of the excess glue that we have on it. Finally, the last piece is to bring it back to the drum sander and get it to final thickness.

When I was done, I put some napthla on the back just to see what it would look like when it is finished. As you can see the curly grain comes out and the rosewood looks really nice against the Koa. This piece of Koa has a lot more figure than i originally had thought. I am very excited to see what it looks like completed.

The next step will be to start bracing the back. We will move on to that step in the next week or so.

Continuing on the neck

We let the scarf joint rest overnight, just to make sure that the glue had set. When I came back in the shop, there was some cleaning up to do on the head stock. I leveled the headstock down using a planer and then sanded it to make it completely flat. At this time, I set the nut witdth and determined the size of the neck. On the picture, you can see the drawing of what the final look of the neck will be. Using a spindle sander, I was able to take down the area that will make up the nut of the neck. This allows for me to be able to take the neck down using a band saw.

I then cut the channel for the truss rod. This is a metal rod that is placed inside the mahogany, underneath the fingerboard. This allows for additional strength of the neck. Additionally, some truss rods - like the one that I will be using, allows for slight changes in the relief of the neck. This means that you can allow for the neck to be a little convex or concave. This metal rod, which will be shown more later, allows a player to make modifications in that shape so that the string height is correct. I also cut the the excess wood off the sides of the neck and head stock.

In this picture to the left, you can also see the Koa veneer that will be glued onto the headstock and act as the head plate. This will be discussed more later, once we are ready for the glue up.

Okay, this is where this build gets a little crazy. So, for the past few posts, you have seen images of a beautiful piece of mahogany that will be used for the neck. Mahogany is kind of a finicky thing. It is important to use quality material and that the wood has straight grain and is quatersawn. Well, my instructor Dan came in to the shop before I got there and he saw that the wood had begun to twist. The grain may have had a little runoff, which caused this. Due to the nature of what we are doing with the neck, it is very important to not have the neck twist on you. Therefore, we had to completely scrap the neck and start from scratch. It is the nature of the beast of being a luthier. Your instrument is only as good as the materials you use. Therefore, we completely re-did everything that I had originally showed you. Since I would rather not bore you to death again, we will just act like this never happened and go on from here.

At this stage in the game, I began to shape my Spanish heel. I first drew the contour of the bottm of the heel out on the mahoganny and began to shave away a lot of material using a chisel. What I was trying to accomplish was a completely flat surface on both sides that would look like the base of a triangle. The reason that we do this now, and not when we do the neck shaping is becuase the area we are working with is a very delicate area. This is where the sides of the instrument are to be glued in. If we did the heel shaping when the sides were in, we have a likelihood of causing damage to the sides with the chisel and rasps. I continued with this for quite some time until I felt comfortable with flat surfaces. I then began to take additional wood out with the chisel to make sweeps that look similar to the traditional heel. When I felt comfortable with that, I used a radiused sanding block to make it so both sides looked the same. This can be troublesome, so you want to take extra care so that each side looks identical. Here you can see the contour of the heel looks relatively similar on both sides.

At this, I began to make a series of faceted cuts along the heel in order to make the contour of the heel continue towards the back. This is a relateively delicate process as mahoganny sometimes likes to chip out when you use a chisel. Once those cuts are made, I took a rasp to the cuts even them out so that there were no high spots. This process takes a bit of time as you constantly have to look at both sides and use your fingertips to feel the high spots and the low spots. Finally, the last step in heel carving is to take a sanding drum, to the heel. Finally, after a few hours of work, the heel was finished.

Once the heel was completed, I then glued up the headstock veneer. Though the headplate is usually looked at as a decarative piece, it also allows for additionally stability where the strings are attached to the neck. Without this, there is a possibility of the headstock separating from the neck altogether. For this guitar, I have decided to use a nice piece of curly Koa. It matches very well with the top, back and sides, so I think it works very well. I have put a thin piece of white laminate between the mohaganny and koa, just to offset it a little bit.

As you can see we put a fair amount of clamping pressure on the veneer. This is to make sure that we do not see any gaps between the layers as aestically, it would not look right with them.

We let the glue set for a few minutes using spring clamps (the orange ones you see above), and after the glue has set a bit, I put luthier clamps on the headstock, as this will give added pressure.

At this time, the neck is pretty much ready to be set up with the body of the guitar. I will most likely do some work on the headstock, to get it set with the slots and the tuner holes. But that will come later.

Finishing the top and starting the neck

So, I continued to build my braces and glue them up. Each brace is a similar process, so I won't bore you with additional pictures and prose about what I am doing with the go deck. However, after a little time, we have the bracing all completed for the top. Parlor guitars, since they are very small, do not need a lot of bracing. To the right you can see the finished top. All it needs is final sanding and it will be ready to go.

Next, it is time to begin builiding the neck for my guitar. This guitar will feature a one-piece mahoganny neck with a "Spanish" heel. If you have ever played a Martin guitar, you know the type of heel that I am talking about.

The first thing to do is cut the piece down to specifications. You may be able to see the pencil marks on the wood to indicate what those specs are. There is no sense it taking a big hunk of mohaganny and wasting a whole bunch of the material. Additionally, by doing a few different things, we can strenghen the wood in order to allow it to withstand the extreme force from the strings.

One thing that usually adds strenght to the neck is using a scarf joint for the headstock. This is where we take careful measurements of the neck blank, cut the wood and the re-glue it so that it has an angle where the headstock will be. This helps to make the headstock more stable and also is the best transmitter of neck resonance to the body of the guitar. For this headstock, since it will be a slotted headstock, we chose to make the angle of the headstock 10 degress, which is less than that of a typical steel-string guitar.

Once the cut has been made, it is time to make the two pieces that we have ready for glue up. This is done by planning down both sides so that the pieces are flush when the are put together. If these pieces are not flush, then you will see a gap between the two pieces. Additionally, the stength of the neck will be comprimised.

Finally, it is time to glue up the head stock. The picture shows how we use a block of wood to force the two pieces together. This is a very important glue up, so we use a lot of clamping pressure to make sure that the two pieces are tightly fit. After a few minutes, we flip the neck over to view the other side. This is done so that we can make sure that the two pieces are firmly together.

We then let this join tack up and sit for at least an hour or so before we do anything else. This is one joint that we definitely do not want to comprimise, as it is very important to the integrity of the neck.