Quick Update

Happy New Year!

I spent the past week in the workroom busy with the guitar, however, I have not managed to keep the blog up to date. I thought I would post a quick update today, and then provide details over the next week or so when I am back at school.

Over the last week I managed to build, veneer, and attach the neck and headpiece, create a bridge, and fit and attach the soundboard.

Here is a picture of the progress:

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Back Glued to Sides

With the back braced, it is ready to glue to the sides. Yesterday, while waiting for braces to dry, I also lined the sides with kerfing to prepare them to accept the back. Today I fit and glued the back to the sides.

Lining, or kerfing, is a way to thicken the sides where they are attached to the back. Without kerfing, the sides are too thin for a strong glue joint, and the guitar would likely fall apart without much pressure. Throughout history, kerfing has taken many forms, from small triangles of wood spaced around the perimeter of the guitar, to continuous strips of wood bent with heat and glued, to strips of wood sliced and bent to the shape of the guitar. On the first classical guitar I built, I am ashamed to say that the spruce kerfing looks rather like crooked, rotting teeth. On the baroque guitar I bent strips of bass wood to fit the curve of the sides. It looks rather nifty. The only problem I encountered with this method was that the arch of the back required me to line the back in two pieces per side, rather than one continuous piece. On the steel string I cut almost all the way through strips of bass wood at quarter inch intervals to create a floppy strip of lining. This is a bit of a tedious method, but it is simple and effective. I had a couple leftover pieces of this lining, and that is what I used to line this Baroque guitar.

The strips of kerfing, once ‘kerfed’ (sliced into floppy strips of wood), are simply glued in segments to the sides of the guitar:

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The final product looks like this:

Continue reading Back Glued to Sides

Bracing

The humidity in the basement is sitting steadily at about 40%, which is fantastic for gluing braces, so I took the opportunity and braced the soundboard and back yesterday.

The plans I am using as a basis for this guitar are fantastic, however, they are missing one crucial element: the heights of the braces. The brace locations themselves are clear, if possibly inaccurate (the plans include this disclaimer, saying that brace locations were determined with an X-ray, and therefore could be slightly off). For the first Baroque guitar I built with these plans, I presented the question of brace height to Michael Schreiner, a respected early instrument builder from Toronto. From other plans he suggested that the braces could have been about 25 mm high. The braces in the first guitar are about 25 mm high, with tapered ends.

This time around, I figured I would do similarly. Then I went looking for brace wood. And I read part of a lute building book (Historical Lute Construction by Robert Lundberg). Lutes are traditionally braced with grain running parallel to the soundboard, opposite to the perpendicular grain used in modern classical guitar construction. Lundberg suggests that part of the reason for this grain direction is that most of the brace wood would have been salvaged from cut-offs from the soundboard. This seemed to be a very economical method of obtaining brace wood, so I took a look at my leftover soundboard wood. It is beautifully quarter-sawn with perfectly tight, straight grain. Using the (perhaps misguided, I will admit) logic that guitar construction was not yet standardized by any means, and that guitar construction was likely influenced by lute builders of the time, I chose to brace this guitar with grain running parallel to the soundboard. (below you can see a rather poor diagram of the two choices of grain direction, as created by me and Paint)

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The Stradivarius Baroque guitar is actually fairly strongly braced when compared with some other guitars from the period. There are 3 cross struts on both the top and the back, all about 5 mm thick and of questionable height, as discussed before. These cross struts run across the upper bout, waist, and lower bout on both plates.

I chose to use as much leftover soundboard wood as possible for the braces. I managed to salvage enough wood for three braces from the cedar for this guitar. The remaining three braces I cut from another piece of cedar, from my first classical guitar. To prepare the braces I marked and cut out the braces with a coping saw, and cleaned up the faces and thinned them to 5 mm. I then trued one edge (the gluing edge) with a sanding board. All except the soundboard upper bout brace were slightly arched for strength. Although this was not necessarily a practise at the time, it does increase the strength of the instrument. The arch is subtle, so I feel that the sacrifice of tradition for strength and longevity is acceptable at this early stage in my development as a luthier.

I then glued the braces one at a time in place, respecting the center marks I had previously made on the plates. I clamped the braces with a combination of cam-clamps and medium sized spring clamps (see below).

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Once dry, the braces are chiselled to height, tapered, and sanded smooth. A more careful and intelligent woodworker would probably choose to use a block plane to achieve an even height on all braces, however, I am not that woodworker. I love a good chisel, so I chiselled all of my braces to about 20 mm high, then sanded them flat. Then I used the same Japanese chisel to taper the ends (from about 2 – 2 1/2 inches away from the ends). Then I chiselled away the corners along the length of the braces. I finished by sanding them with 220 grit sandpaper.

The soundboard also is reinforced in a few places with small pads of soundboard wood. Three pads are located around the soundhole for strength, and another two located asymmetrically on the belly of the guitar. I cut these out of soundboard scraps, sanded the glue side flat on a sanding board, and glued them to in place. Once glued, they needed thicknessing to about 2mm (again, I used a chisel here, perhaps not the most appropriate tool), and shaping. Basic principle of shaping braces and pads: sharp corners are frowned upon, generally.

Before completing the soundboard, I carefully glued the rose in place.

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The back required a little less work than the top, as seems to always be the case. After the braces were sanded smooth, I merely had to glue strips of paper along all of the seams from piecing the back together.

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And with that, the top and back plates are braced and ready to go!

The Rose: Part 2 and Completion

Having finished the first layer of the rose around the end of September, I glued the carved piece to a second thin piece of cherry, marked the design and drilled holes to start carving layer 2. I also thinned the carved layer to about half of its original thickness by sanding.

Then I had a change of mind and decided to redesign the rose. I took out parts of my carefully carved top layer with a chisel. I had decided to move these parts of the design down a level to give the rose a more open appearance.

The second layer was carved in much the same manner as the first layer, with needle files and lots of patience. I also had to clean up the mess that removing parts of the first layer had left, as well as some glue squeeze out from attaching the layers together.

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In the image above, you can see where I removed the top layer from the design closest to the edge of the circle.

Before proceeding with the third layer, I cleaned up, as much as was possible, the glue, pencil marks, and stray bits of wood with sandpaper, a small Exacto knife, and needle files. I also thinned the second layer a bit on a sanding board.

 

The third and final layer of the rose is cut from a piece of ‘coverstock’ weight paper in a cream colour. Perhaps not the most historically accurate, but it is an easily obtainable, inexpensive paper, and the weight and texture is easy to work with for this project. Because the rose is not entirely symmetrical, I traced the actual rose onto the paper, rather than use my original design. I then sketched out my ideas in pencil, and proceeded to cut out the design.

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Most of the paper cutting was achieved with a basic Exacto knife with a standard sharp blade. The circles were cut with punches I had made for my previous rose out of metal tubes:

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These are quite easy to make: take any sized metal tube (the inside diameter should be the size of hole you require); stick it in a drill press; use a metal file to create the initial taper as the drill press spins the metal tube, and finally; polish and sharpen the taper and edge with fine sandpaper or Japanese water stones. The punches work with a sharp tap from a hammer and leave a rather clean edge.

The design for the rose has no relation to historical roses, and is rather a personal mark on the guitar. I thought the birds an appropriate addition to this rose. Let me know what you think!

The final stage was to carefully glue the paper to the wood layers. For this a very thin and even coat of glue must be applied to the entire back surface of the wood rose. It must be thin, lest unsightly glue squeeze out and ruin forever the hours of careful design and carving work! The paper layer is carefully aligned with the wood layer – and there is only one shot at getting this right, no chance to shift the paper around if it does not land in the right place – and pressed into place.

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The rose is complete and ready to glue to the soundboard. Next: bracing!

 

Carving the Rose: Layer 1

The rose is perhaps my favourite part of the Baroque guitar. While it is time consuming to construct, the intricate and beautiful designs are extremely rewarding.

Take a look at the original rose by Stradivarius. The floral layout served as inspiration for my design.

Here is the rose that I designed and constructed for my first Baroque guitar:

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This time around I decided to use a more floral rather than circular design.

First I prepared the pieces of cherry for the first two layers (the third is a heavy paper). The wood was left over from sides of another project. It is beautifully straight grained and unfigured.  I cut two pieces about 10 cm square. At this point they were around 4 mm thick, so I attached them to a sanding jig for thinning:

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The jig is just a piece of pine with two handles (on the underside in the picture). The cherry pieces are attached with double sided tape. I just flip the jig over, run it over a sanding board for a while, and voila! the pieces are evenly thinned. I thinned the pieces to about 2 mm, which is thick enough to withstand carving. After the layer is carved, I will thin it further, to just over a millimetre thick.

After sketching my design out on paper, I transferred the first layer design to a piece of cherry:

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Then I drilled holes in all of the negative spaces to prepare for carving.

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Which resulted in a strange looking pattern of holes:

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Using needle files (pictured below) I stretched the circles and removed all the excess wood. I mainly used four files: a small oval file, a one sided flat file, a triangle file, and a larger oval file. A couple of the sharper points needed to be touched up with an sharp knife, but most of the work was accomplished with these four files.

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This resulted in the first layer of the rose complete (albeit a little rough and still too thick):

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The next stage will be to glue this (with grain perpendicular) to the second piece of cherry, and then to carve the second layer of the rose in a similar fashion to the first.