Pernambuco \ Western Red Cedar Falcate Classical Blog:


March 4th 2019

Thanks guys! I got back from Indonisia last week and started back up this guitar. I went through the process of making the top and back braces and bracing up the plates.

I start with the back braces by using a 27.5 degrees router bit to make house gabled shaped braces.

I used my radius stick to mark, rough out with a plane and then clean up on the radiused stick.

Used my gobar deck to glue them down.

I reinforced the seams after glue up on this guitar as it is my first three piece back.

On to the top.

First off I thickness the top to close to my final target and I glued on a soundhole patch,

I taped on a 5 mm sheet of mylar on the top and sealed the sound hole trying to protect the top.

I ripped some sitka for the main falcated braces and some other spruce for the secondary falcate braces. The strips are 1.7 mm thick. I rip them a bit thick and clean them up in a drum sander. I use three to make a brace. I bend the strips into the falcate shape on a hot iron.

I use west system 105/206 epoxy to laminate the braces

Each laminate is tall enough for two braces.

I worked out the brace positions and the edges of the inside of the top.

On the last few guitars I have routed a channel for the carbon fiber tow. I route a touch deep and and back so that it is only about 5 mills deep.

I finally found some 3K tow that I do not need to buy by the lb.

I start out with everything laid out. I paint the brace locations with epoxy, I use my gloved fingers to wet the tow, I paint the bottom of the brace and lay the fiber in the channel I routed. Making sure I clean my hands between the steps I lay the braces out and use the gobar deck to clamp.

I used a small and plane to shape the falcate braces and laid out the tertiary braces and the sound hole braces.

I went through the same lay up process to glue them down.

After those braces cured I added the top layup up of the CF tow.

The final step was to fit the transverse brace and glue it on. I mark it out with a scalpel. To cut the channels I clamp it the depth of the cut in my parrot vice and cut down until I hit the vice. I then use the vice to control the chisel cut to clear the waste.

I used a plane to put a radius on the ends leaving the center of the brace flat.

More tomorrow.

March 8th 2019

I finished up the plates and use my pencil mill grinder to notch the linings for the top.

I had to complete a few construction steps this guitar has a sound port. I hate installing a sound port as I always feel I am hacking the rims. I use my pencil mill grinder but it is always scary has the bits sometime catch and want to run. I am really too deep for the size bit I use. This time I opened a hole and used a coping saw to hack it out. I then used a rasp and the mill grinder to finish it.

Hoping not to forget anything I made a closing checklist. I think I have forgotten at least one thing I wanted to before closing on my last few guitars. Not really legible but it did help.

One of the steps was to double check the tops rim profile such that the top under the fretboard extension has the correct neck angle. At this point it is about 2 mm tall at the saddle location. Classical guitars are generally -2 mm but this guitar uses a 4 mm wedges to correct the angle created radiusing the top. In any case I am good at this point.

Before installing the end graft I wanted to bend the cocobolo, I only have a couple extra and the venetian cutaway bend is hard. I did it first on a bending iron. I used rims for my guide. I thought I took more pictures but I did manage to bend the cutaway bindings. I used the side bender to bend the normal side as it was easier and I was sure to be successful.

With good bindings I installed the end graft.

I installed a couple of patched on the the back to reinforce the two wings I needed to make the back big enough, you can see them near the bottom brace.

Triple check that the top is ready ...

Gluing and clamping ...

March 11th 2019

This weekend I got the box closed and bound. All and all I am happy with the results. Both the look, I love the pernambuco and the early tap tone.

Here is how I got there from the previous post.

I closed up the back. With the top glued on glued on the I glued on the back without the mold. The reverse kerfed linings make a rigid rims so I just made life easier.

I use a spiral flush cut bit with just a touch more than the depth of the back exposed.

I used a scraper and a touch of sanding to level the sides. I spend more time here than I have in the past. It has dawned on me that trying to level with the bindings on does not go well. I have found myself cheating to get a level look on the rims without narrowing the bindings.

I replaced my fancy Luthiers Tool head with an LMI rabbit bit with the correct sized bearing on my Fleischmann binding jig. On the last guitar I found a bit of slop in the tool between the guide bearing and the router mount causing a messy channel depth. I was able to clean up the channel on the last guitar but it was a real pain. I like the tool so I will work to figure out how to remove the slop.

A good fit!

I cut the neck rim transition rabbit by hand using a scalpel to make the cut. (They are sharp with a new blade). I used a paring chisel to remove the waste.

I went ahead and mitered and glued in the transition piece. I debated about leaving it to the end but I did it first.

I wanted the binding channels perfect so I spent a lot of time fitting the bindings. I taped them on cut them to length and checked the entire binding to make sure that the channel allowed the binding to fully sit. To help I break the inside corner of the binding. I would test fit and mark the rim with a pencil where I found that the channel needed a bit of work. I used a combination of a scraper, a chisel used as a scraper and a sanding block to clean and square the channel.

I break the outside edge to keep the binding tape for ripping

I use a scarf joint at the heel and glue the binding that makes a pocket first to make it easier to get a good joint with the second binding. The binding can not slip. Here is a dry demonstration.

all and all there was a lot of tape involved. The binding were near perfectly flush of the sides and just a touch proud on the top and back. Other than glue most of the cleanup was done with a scraper to get the tops of the bindings flush.