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148K views 33 replies 20 participants last post by  maagz 
#1 ·
The Kit

I have started taking a classical guitar construction class at Red Rocks Community College in Lakewood, CO. I'll be blogging about it here as my journal through the process.

The kit that we are using is the KLC guitar kit from Luthiers Mercantile International . The kit has all the wood and hardware for building a classical guitar. It also comes with a DVD - "Build a Classical Guitar with Robert O'Brien". Robbie is the teacher of our class. He teaches several classes each semester and also offers private instruction. You can see and hear an example of building this kit on YouTube .



Here are some pictures of the wood that comes in the kit.

The bookmatched Indian rosewood sides and back.



The bookmatched Engelmann spruce top.



Bracewood, kerfing, etc.



Mahogany neck, ebony fingerboard, headstock veneers, etc.



All the wood looks (and smells) great! Not pictured above are the fretwire, tuners, guitar plans and dvd that also comes with the kit.

My next entry will look at building the neck blank and headstock.
 
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#3 ·
Hi Scott,

The class is a full semester (3.5 months). There are some specialty tools that are needed like a bending iron and drum sander. This is my first guitar so I don't know yet everything that is needed. LMI also sells "serviced" kits that have some of the work done that require the specialty tools. You might check with them about those kits.

That would be a pretty nice Christmas gift! I've heard several guitars that other students have made and they all sound great. I can't wait to see how mine turns out.
 
#7 ·
The neck and headstock

The first step in making the neck blank is to make a scarf joint. This creates the tilt back headstock. I laid out and cut a 15 degree cut on the neck stock with the bandsaw.



After cleaning up both sides of the scarf joint with a jack plane, I glued the joint together. You can see the short piece from the cut is flipped over and glued to the back side of the neck stock to create the angled headstock. The long piece should overhang the shorter piece a little bit.



I made a little mistake gluing this up with my caul on top overlapping the joint. I had to re-clamp after moving the caul back, so it didn't end up glued to the neck blank.

The next step was to thickness plane the headstock and neck. The final headstock thickness should be about 22 mm. Since the two headstock veneers were about 4 mm thick. I had to make the neck blank 18 mm thick on the headstock end. This was done using a bandsaw and jack plane.

The scale length was then tapered from 17 mm on the nut end to 23 mm on the heel end. This was done by repeatedly making three passes on the jointer. The first pass going a third of the way down the neck, the second pass two-thirds of the length and the third pass full length. I made these three passes on the jointer three or four times to get down to the desired thickness.

Next the two veneers, a thin white and a thick rosewood veneer, were then glued onto the headstock.

Headstock template
For the shape of the headstock, I sketched a number of different designs. I cut out the final design and traced it on a piece of 3/8" MDF.



I used a bandsaw and oscillating spindle sander to cut out the outside of the template.





To cut the inside of the template, I taped another template on top of mine and used it to guide the interior cut.



The cut was made using a drill press and a special bit made by our teacher. The bit was made from a drill bit blank with an edge ground into it. The length of the edge is two times the diameter of the bit.



Taking small bites, the bit transferred the pattern onto my template.



The Headstock

Unfortunately, I think the old template moved a little bit so you can see the holes on my template don't line up exactly. Anyway, the centerline of the template was then aligned with the center line of the neck blank. The template was positioned such that the nut end of the string holes would be 30 mm from the apex of the neck/headstock angle.



The outside shape of the headstock was then cut using the drill press and special bit.

Next, I used a drill guide to drill the holes for the tuners.



Here you can see the quality of the cut with the homemade bit. Not bad!



With the tuner holes drilled, it was back to the drill press to cut out the interior holes of the template.

Here's the result with the tuners in place:





One other step here was to trim back the veneers that were glued on with a slight overhang over the scale length. This was trimmed by placing the neck on a spacer and using the table saw so the blade only cut the veneers. I went a tiny bit too far so you can see the slight groove (dado?) just below the veneers. I'll have to sand the scale length down to get rid of that groove.
 
#8 ·
That is an interesting way to do template routing. I assume the second template is a master provided by your teacher. Did you use anything to stick the master to your template? I always use double sided carpet tape so my templates don't slip.

Nice work. Keep the blog going!
 
#11 ·
The heel

The next step in the construction of the neck blank is attaching a heel block.



In this guitar, we are using a Spanish heel to attach the neck to the body of the guitar. The Spanish heel uses two slots separated by about 11 mm in the sides of the heel block. The guitar sides will then be inserted in these slots. You can see the slot in the next photo, but this will become clearer when we attach the sides.



In roughing out the shape of the heel of the guitar, the first cut (done with a bandsaw) is the curve shown above. The second cut with the bandsaw forms a ramp on the side of the heel.



At this point, I finished shaping the end of the heel block which will be inside the guitar. Then, I sealed the end grain with shellac.



In this picture, you can also see a wide rabbet on the end of the heel block. This is where the top will be glued onto the heel block.

Back to carving the heel, the third step is to put a curve into the ramp that was formed in the second cut above. This was done using chisels. I used a little template to help me make this slight curve the same on both sides of the neck.



The primary facet was then carved. I tried to make the facet look the same on both sides of the neck.



Secondary facets were then carved on both sides of the primary facet and from there it was a simple matter of smoothing everything out.



This was my first experience carving wood and it felt good being close to the wood with just a chisel. This mahogany was really nice to work with.

I'm done with the neck blank for now. I'll finish carving the neck once the guitar body and fingerboard are attached.

 
#15 ·
The sides

The first step for the sides is to thickness the bookmatched sides. In the kit, these sides are about 4 mm thick. They need to be brought down to about 1.8 mm thick. We first used something called a Safe-T planer which is a drill press attachment that can remove material very quickly. Just like a regular thickness planer it creates a big mess quickly.



A drum sander was used to get down to final thickness.





Next we jointed one edge of the sides. This edge will be the edge where the top sits. The back edge of the sides has a slight taper from where the waist of the guitar will be to the neck. This taper gives a first approximation to the radius on the back of the guitar. It will be refined later using a radiusing dish.



It was now time to bend the sides. We used the following jig to bend the sides.



Each side was first wet with water and then wrapped in moist paper towels. This was then placed on the jig making sure the taper was facing the right way. A rubber heating blanket and flashing was placed over the side.



As the wood heated up, the side became more pliable and could be bent into the shape of the jig.



A tail block was made with a slight curve to match the form that was used for the guitar. The sides were glued on to this tail block.





Next the sides were glued into the Spanish heel making sure to keep the top edge of the sides flush with the top side of the end of the heel block. It only took a couple of drops of super glue on both the top and back side of the heel to hold this in place.



Here's the assembly in the guitar form.



Next, I scraped and sanded the inside of the sides to remove the marks left by the drum sander.



After planing the top edge of the sides and tail block so that these lay completely flat, the back edge of the sides, tail block, and heel block were shaped to conform to a 15' radius. This was done by both planing and using a radiusing dish. I didn't get a picture of this step, but I'll have another chance when we radius the back braces.

With both edges properly shaped, the kerfing was glued onto the sides. To hold the kerfing in place while the glue dried, homemade clamps made from clothespins and rubber bands were used.

 
#16 ·
This is a very cool blog series and I'm putting this on my favorites so I dont miss anything. I'd love to build one of these some day. Has the photo taking for this blog been a disruption? Seems like it would at least slow you down some. It's pretty cool that your instructor is letting you document this here.
 
#21 ·
The top

The kit for this classical guitar came with a bookmatched pair of Engelmann spruce boards for the top. My pair has some beautiful silk in it that I hope will come out in the finish. After jointing the inner edges of the two boards and tapering the opposite edges. We used a wedge jig to glue up the top. The wedge applies the clamping pressure to the joint in the middle of the top.



I then used hand planes to surface the outside of the top.



The next step is installing the rosette to this outside surface. We used a Dremel and a circle cutting jig to make the channel for the rosette.



To glue the rosette into the channel, we used the go-bar clamping system. I didn't get a picture of this but you'll see plenty of examples of using this clamping system as you read on. I flushed up the rosette to the top using a block plane and cabinet scraper. You can see some of that sweet silk in this photo!



Using a drum sander, the top was thicknessed to 2.6 mm.

For the bracing pattern, I used the one included with the kit which is the pattern in Segovia's Hauser guitar.



The first piece to be glued in is the bridge plate. I made a bit of a mistake here with the bridge plate. You can see it doesn't really match the pattern above. That's because I made it before consulting the pattern! Oops.



Here are all of the spruce braces after cutting them to size and roughly laying them out.



You can see some of the braces need to be notched to fit over the bridge plate. Robbie showed us a clever way of doing this using a bandsaw. Check out his youtube video.



Here is a picture of the first set of braces to get glued in with the go-bar clamping system. This system uses flexible rods bent between two decks to apply pressure.



The reason for gluing the braces in in steps is to give you room to shape the braces using small planes and chisels. Here is how I shaped the fan braces.



Here's the final glue up of the remaining braces.



And here is the inside of the top after everything has been shaped. At this point, you can tap the top and hear a satisfying resonance that sounds like a tuned tom-tom.

 
#30 ·
The back and back braces

In this part of the series, we'll look at making and installing the back braces, making the back, and prepping the sides for the big glue-up.

In this guitar, I put in four back braces. These braces were made from 7×15 mm strips of Spanish cedar ripped on a bandsaw. The braces were given a rounded profile on the side facing up when you look through the sound hole.



After cutting the braces to length, the ends of each brace on the rounded side were chiseled flat. This would be the side glued down onto the kerfing.

The back of this guitar will be slightly rounded to a 15' radius. So before installing the back braces, the kerfing on the sides were radiused using a 15' radius sanding dish.



In this photo, you can also see that I have already leveled the kerfing on the top with the sides and notched the kerfing to receive the cross braces on the top. This was a painstaking process because you want the top of the sides to be dead flat when you glue on the top. It involved many iterations of flipping the guitar upside down on a dead flat surface, looking for gaps, flipping the guitar back right side up, and shaving material off to reduce the gaps. Occasionally, I would break off a piece of the kerfing and have to glue it back in and wait for the glue to dry.

With the back kerfing properly radiused, I notched the kerfing with chisels to receive the back braces.



The first brace was placed at the waist and then one brace was placed to roughly divide the upper bout in half. The last two braces were placed to divide the lower bout into thirds.



I chose to place the braces so that the notches fell on full kerfs. This made the braces not perfectly parallel, but I figured I wouldn't be able to see that anyway in the finished product. This picture is also nice because you can see what the inside of the guitar would look like with the back removed. Kinda neat!

The braces were glued in without any clamps, just placed in the notches. The braces now had to be properly radiused. A block plane was used to remove most of the material.



Then, the sanding dish was used to arrive at the final radius.



The back panel can be glued up in the same way as the top. The only wrinkle is the added center strip. We actually glued the panel up with a technique that involved eight hands, CA glue, accelerator, and frustration. I think I prefer the simple wedge jig and yellow glue.



My back was made from a bookmatched pair of East Indian Rosewood. This LMI kit came with some great looking wood!

The final piece of the back was the center strip which was glued in using the go-bar clamping system that we saw in the last post on the top.



After scraping and sanding the inside surface of the back, I laid out where the center strip had to be notched to receive the back braces, heel block and tail block.



Here is the back after notching these areas out with a chisel and scraper. The final step before gluing up is rough cutting the outline of the back slightly oversized on the band saw.



Next time, the big glue up!
 
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