This instrument was actually begun last winter, but is only now coming into completed form. The back, sides and neck are all salvaged from a tree taken down years ago on my wife’s parents’ property, where she grew up. (I built a commissioned instrument from this same tree last year.) I wish I had a lot more of it but much of the tree was lost to rot. Too bad… it is pretty wood. The Sitka spruce top came from somewhere here in the northwest, but I don’t know esactly where: I bought it from a local wood dealer.
Eventually I had the corpus (body) completed and had begun working on the neck and scroll. Arthritis was plaguing me a little, so it was slow progress.
Then it was time to set the neck. This is one of the most exacting steps in building a violin: everything has to be correct, or it will be impossible to correctly set the instrument up for playing.
Once the neck mortise is completed, such that the neck fits perfectly and all angles and dimensions are exactly right, I liberally coat the mortise and neck-heel with hot hide-glue, and quickly ram the neck into place, check all measurements one last time and clamp it with a single clamp at the heel.
After all the woodwork was completed, I varnished the instrument: The first coats are quite yellow, to provide a “golden glow” from under the color coats.
Finally the instrument was fully varnished and set-up:
The sound on this fiddle is very strong and clear: it has a well-focused C-string and is well-balanced across all five strings. I think this is possibly my best instrument so far.
This week was a hard one, in terms of getting things done, because I had some repairs to do; but I did complete the varnish prep work on the most recent five-string violin, and then rubbed into it the mineral ground I use to fill the wood pores and prevent excessive varnish saturation.
The mineral ground dried rapidly, allowing me to accomplish the final rubdown before varnishing began: so, this evening, I applied the sealer, which is designed to soak in, and lock the mineral in place, after which the solvent evaporates, leaving only the resin in the wood. I rubbed off the excess with a rag and alcohol to make sure no unwanted residue was drying on the surface.
So, here is how it looks today. From here on out, it will be varnish and set-up:
I always hang the fiddles in the dining room to dry, since we heat with wood, and that is where the woodstove is.
This is a pretty accurate view of the color, so far: I intend to use yellow varnish as my base coat(s) to produce a golden glow from within the color-coats.
So, when I saw that there were two sections of “scrap” left over, near where the neck end of the five-string double bass back was cut out, I realized that a 5-string fiddle back could fit into each of those two pieces.
So, I salvaged the wood, and not only got two backs, but also the neck blanks for two 5-string fiddles.
Five-string fiddle back cut from the scrap left from a 5-string double bass back.
Arching the Plate
I really like the look of the Oregon Big Leaf Maple back wood. I enjoyed arching the plate.
Purfling the Plate
On all my five-string instruments I usually include a purfling weave. It is a modified fleur-de-lis I designed for my first five-string fiddle and have continued to use on subsequent work.
In this photo, the slots for the purfling have been incised, but not cut deeply, so the next step is to slice deeply enough that the waste wood can be removed from between the cuts, and the purfling strips inlaid in the resulting slot.
I will include the purfling process in subsequent posts.
When I last posted, I had the garland pretty much complete, and the materials were prepared for the neck and the front and back plates. I had cut the back plate roughly to shape, in order to use as much of the “fall-off” material from the back plates, as possible, from which to make the neck.
I went ahead with the neck and scroll, just because I find it encouraging to have some of the “pretty” work done, as it makes me feel that I am making progress. You can see the neck progress, here.
But at some point, one has to go ahead with the task of bookmatching the plates and getting them ready to carve.
So, for the front and back plates, the next thing on the agenda was to plane the center-joints absolutely flat and straight and then glue them together. It took two tries on each of them, as it turned out that while they were technically “straight”, and if I put a try-square at any given point, they seemed to be square…in reality, there was a longitudinal twist to the surface I had planed, and the fit was not acceptable. (sigh…) No big deal… I just had to saw the joint back apart, and try again.
Finally, I got everything lined up correctly; then I glued and clamped the plate halves together, and produced the plate banks, ready to trace the actual shapes.
Tracing the plates
Tracing the plate out with a pipe spacer like that enables me to establish a very even overhang of about 4.5 mm. The problem is, it also makes round corners, which I did not want. So I had to correct, the corners, using a long straightedge to “point” the corners toward the center of the plate at the far end, and then use circle templates to extend the curvature of the plate edge above and below the corner to meet the straight lines. (Incidentally, the reason I have stopped using a washer for a spacer, is that any washer small enough to have the right distance from outside to inside also is so thin that if there is the smallest change in the fit between the plate and the garland, the washer will slide under the garland, changing the overhang distance to zero. The thin slice of PVC pipe never does that.)
Cutting out the Front Plate
I used an old Craftsman “Auto-scroller” saber-saw (Hand-held jigsaw) to cut out the perimeter of the front plate. Ann, my beloved wife, bought me that saw 36 years ago, when we had been married for only about three years. That little saw has a lot of miles on it!
Arching is Next:
Before I could begin arching, I needed to mark the intended plate thickness: I used a marking tool to scribe a line all the way around the plate at 6 mm. Before the plate is done, this will be reduced to 5 mm in most areas. I used a ballpoint pen to highlight the groove so that I could more easily see it when I am working, and not accidentally go past it.
Then I secured the plate in a cradle especially made to fit this design, and secured it in place by affixing small squares of 1/4″ plywood around the perimeter so that the plate will not shift laterally, while I am working on it. The reason the little stop-blocks are so thin is that I do not want them to be in the way when I am planing the edges.
Time to lay out the F-holes!
When I build the smaller instruments, I inside the f-hole perimeters quite deeply, knowing that, without exception, I end up needing to correct the arching, using the f-hole side-profile as a guide. I want the “stem” portion of the f-holes to be essentially parallel to the plane of the garland-plate joint when viewed from the side. On the violins and violas I have built, I have universally found that, in spite of my best intentions, I have left too much “puffiness” in the area of the lower wings of the f-holes and I need to plane away more wood. If I have incised them deeply enough, I don’t lose the marks when I remove the wood.
I was quite pleased to find that, on this instrument, the side profile was exactly what I had hoped for, as soon as I laid it out. So I incised them, but not very deeply, and then inked them with a ball-point pen, so that I could easily see them while perfecting the arching later, using a scraper.
So– the next step will be to complete the “graduation” of the plate– carving away the majority of the wood thickness from the inside of the plate, so that the plate is the correct thickness all over…ranging from 9mm at the center, all the way down to 5mm in the flanks.
Varnishing Process for the 16-1/2″ five-string Viola:
All Smoothing and Varnish-prep is done:
When I last posted, the final woodwork had been completed. I had twice wetted down the wood, to raise the grain, and scraped and sanded away the rough raised grain. The wood was stable enough to commence the tanning process.
After the wood is smooth, there will be:
a tanning treatment,
a mineral ground treatment,
a sealer, to lock the mineral ground in place, and
finally, the varnish itself in a series of 6-12 coats, depending on color.
Tanning the Wood
People who live in very sunny regions (New Mexico, for instance) need no light booth: they simply hang their instrument out in the sun for a few hours and it takes on a deep yellow-tan color. I live in Oregon. Western Oregon, between Portland and the coast. We are more likely to achieve a patina of bird-droppings than a sun-tan, if we hang instruments outdoors. (Sigh…)
So, a number of years ago, I bought an old cabinet, about seven feet tall, lined it with aluminum foil as a reflector, wired it with a strong UV source (two 48″ fluorescent UV tubes in a shop-light fixture), and I hang my instruments in it overnight. To heighten the effect, I brush on a coat of very diluted Sodium nitrite and let it dry before I expose it to the UV. This works pretty well, and I have pretty much adopted it as a normal pre-varnish treatment.
Years ago, an excellent luthier in Europe posted a detailed explanation of why and how he employs a mineral ground in his instruments, to improve projection. I tried it (because, “if it is good enough for Roger Hargraves…”) and immediately started getting better reviews on the sound of my instruments.
So…obviously, that became part of my process, as well. I use gypsum powder, suspended in coffee (gotta wake up the tone!) so as to achieve a little deeper color in the same move. I rub it in vigorously, trying to get the particles of gypsum to actually penetrate the pores of the wood, then rub off the excess with a rag, before it is fully dry. When it is dry, it obscures the grain, and turns a chalky white color.
The sealer, in this case, is simply rosin, dissolved in turpentine and alcohol. The mixture soaks into the wood, causing the mineral ground to become transparent, then the solvents evaporate, leaving the rosin in the wood. The mineral ground will never again be visible.
When the sealer is dry, I sand lightly, using 320 grit, to remove any lumps I may not have seen, and then I am ready to begin varnishing. I always begin with two base-coats of very yellow/gold varnish, so that the gold color will shine through the darker color coats.
I like the way the European Maple and Spruce are shining through the varnish. I think they will sound great, too. Tapping on the corpus, it sounds as though it will have a big, deep voice.
I will follow the completion of the varnish process in a later post.
Almost done with the Wood Work parts on the 16-1/2″ five-string Viola!
Completing Arching of the back plate.
When I last posted, I was nearly done arching the back plate, and nearly done shaping the neck:
Setting the neck
I forgot to take photos during this process: sorry. I get wrapped up in the work and forget all about taking photos.
Setting a neck follows this course of action:
Prepare the neck heel– angles and dimensions all correct. Heel absolutely flat, all mating surfaces absolutely smooth.
Lay out and cut out the mortise in the neck block on the corpus. I try to give myself some room for adjustment. It is always a mistake to try to cut exactly to the layout lines in the first attempt.
Check all measurements with every single change:
how does the centerline of the neck fit, relative to the centerline of the corpus?
how does the transverse level of the neck match the level of the corpus?
how does the pitch (front-to-back) angle compare to what is correct?
how does the distance between the nut line and the top edge of the front plate compare with the correct distance?
how does the height of the lower edge of the fingerboard above the edge of the front plate match the correct height?
When the final fit is perfect, checking ALL measurements, remove the neck and slather in the hot hide glue, and immediately ram the neck into place one last time, making a fast re-check of all measurements, to make sure nothing moved out of place.
Let it dry!
You will notice that I set my neck before closing the corpus. I find it easier and faster, and it allows me to achieve a perfect fit against the back button.
Graduating the Back Plate
The next step was to carve out the interior of the back plate, to achieve ideal thicknesses all over. This is called “Graduating the plate” or, simply “Graduation.”
After I established the current thicknesses for all the above locations, I carved each dot to the thickness I actually desired, leaving a series of pits all over. The following photo was actually of the front plate, but it is the same idea:
After connecting the dots, the graduation is very nearly complete. I scraped, and checked thicknesses, and scraped some more, until it looked like this:
Preparing to close the Corpus
With the back plate graduation complete, I was ready to attach the plate to the corpus, except that:
the corpus was still attached to the mold, and
the blocks and linings had yet to be shaped.
So I sketched in the planned shapes of the six blocks, trimmed the neck-heel flush, removed the mold, and then set about shaping the inside of the blocks and linings.
I used a knife and a chisel and a gouge to shape all of them, finishing with a scraper. The very first step was to sketch in the block shapes.
Then I cut the neck-heel off, flush with the neck block. I used a flush-cut saw for this step. It works well, but you have to watch carefully to make sure it is not wandering off the line.
Removing the Mold
Then I leveled the back of the garland, using a sanding board, and I was pretty much ready to remove the mold. I popped the glue-lines loose from where the blocks were attached to the mold and lifted the mold out. It is a collapsible mold, so I removed the bolts and took the mold out in three pieces. That left me with a completed corpus, and a neck already set, but no mold. At this point the structure is extremely fragile: I have to be verycareful until the back plate is glued on, making the structure rigid and strong again.
The next photo is from an earlier instrument, because I forgot to take a picture of the shaped blocks in this instrument:
Closing the Corpus
Then I installed the label, and dry-clamped the back plate to the corpus, using spool-clamps, checking carefully to see that my position was correct, and that the overhang was equal all the way around.
I then removed a few clamps at a time, and slipped hot hide glue into the joint, using a thin palette knife, and quickly replaced the clamps. When I had spool-clamps all around the perimeter, I added one last clamp, a padded C-clamp, to ensure that the joint between the neck heel and the back button was fully closed and tight. I used a glove to pad the neck, and clamped it securely.
The next thing will be to trim the neck heel and back button together, as they are the key to the strength of the joint, and must hereafter function as one.
But I will leave those steps for a later post…this one is already too long. (sorry…)
I had installed the European Spruce front plate on the garland, and showed the partially assembled corpus in spool-clamps. So, here is the partially completed corpus, out of the clamps and stacked with the rest of the parts:
So, I took a break from working on the plates, and worked on the scroll. It is made of highly flamed European Maple.
I completed the carving of the turns of the volute, and cleared it up until it was nearly complete, including the chamfers around the edges. I used an assortment of small gouges to carve the undercuts, and completed the work using scrapers.
Back Plate Beginning
Then I decided I had better get the European Maple back plate caught up to everything else, so I cut out the traced shape on my small bandsaw, and cleaned and smoothed the perimeter on the oscillating spindle-sander. I began the outside arching, using a toothed-blade finger-plane, and then switching to a smooth-blade finger plane, stopping only because I was getting tired.
I will still have a great deal of careful shaping and scraping before the back arching is truly complete. But before I stopped for the evening, I temporarily glued and clamped the ebony fingerboard to the neck, knowing that I will remove it after setting the neck and before varnishing. So, here is where the instrument sits tonight:
You will notice that I also began shaping the “handle” portion of the neck. I shape it along with the fingerboard, dressing the fingerboard to get the curvature perfect, and shaping the “handle” part of the neck for optimum playability and feel.
But, when the arching is complete, I can sweep straight on into graduation, because, of course, the back plate has no f-holes, let alone a bass bar. (I do have to remember to install the label before I close the corpus. I don’t enjoy trying to install a label with tweezers, through an f-hole.)
The next things on my agenda will be to complete the arching, complete the graduation, and get going on purfling the front plate.
Many makers install the purfling before they begin graduation, but I always had a problem with the overhang being uneven when I did that, so I switched to purfling after the plate is installed on the garland, and the overhang has been satisfactorily established.
I also usually set the neck before removing the mold, so that, when I go to install the back plate, the neck heel is already perfectly flush with the back of the garland, and the back plate fits flush and tight, all the way around. Everyone has their preferences and idiosyncrasies, I guess.
My expectation is that I should have the neck installed by the end of the week…and maybe the back plate, too. But there are always other demands on my time, so it may be next week before either of those is complete.
When I last posted, I had traced the shape of the garland onto the plates and was ready to cut out the plates. I decided to wait on the back plate, but the front plate was ready to go, so I cut it out, using my band saw, and smoothed the edges, using the spindle sander and files. (I have built precisely one instrument without power tools of any sort: One of my early teachers required it, so I complied, but it convinced me that, at my age, I need to save my joints for the things that I have to do by hand, rather than beating them to death just on principle. Besides, I am convinced that if the old masters had possessed power tools, they would have used them without question. They were very practical people.)
So, with the front plate cut to shape, I first marked the edge at a thickness of 4.5 mm. I used a wheel-style marking gauge, with a sharp disc, to mark the thickness and scribe it into the edge of the plate, all the way around. Then I began cutting away waste wood to achieve the desired arching shape. I checked a poster (Published by The Strad) of the “Conte Vitale” 1676 viola by Andrea Guarneri . It is one of the most frequently copied violas in the world, as it is a large viola that works very well, and copies of it frequently work very well, too. I am modifying the pattern a little for superior playability, but I have made this model before, so it is not “guesswork.”
I forgot to take pictures, initially, but here are a couple, belatedly:
F-hole Layout and Incision
Once the arching was complete, right down to scraping, I laid out the f-holes, and incised them deeply into the European Spruce of the front plate. Incising the f-hole outline allows me to turn the plate and sight over the edge of the plate at the profile. I want the main stem of the f-hole to be essentially parallel with the plane of the ribs, when seen from the side. I use this as a final correction for the arching, and without exception, it has required me to correct the shape of the arching before moving on.
Once the arching is truly completed, and I am satisfied with the f-holes, I begin graduating the inside of the plate. This means that I am carving the inside of the plate to “match the outside,” in that it will be an appropriate thickness all over. I usually want the center area between the f-holes one thickness, the band running up the center to each end slightly thinner, and the wing areas outside that area quite a bit thinner. There is no “set” thickness, and each luthier has to make choices in order to achieve what he or she wants from an instrument. Getting what you hope for depends on those choices you make, and the choices were (hopefully) made intelligently, based on the type and density of the chosen wood, the shape of the arching, and so forth. Getting the arching and graduations right is a lot of carving on a large instrument, but it pays off in quality of sound.
Frequently I can see the traces of the incised f-holes from the inside by the time I am finished with the graduation of the front plate. And, believe it or not, I always can easily see light through the spruce plate, in the thinner areas, if I hold it up to a lamp.
Cutting out the F-holes
I use a special tool to cut the upper and lower eyes of the two f-holes, then use a small knife to finish cutting them out.
Once the f-holes are cut out and refined, the next thing is the bass bar. This is the only brace attached to the inside of a violin, viola or cello: it supports the bass foot of the bridge, and provides for clarity and strength to the bass notes. An instrument with a weak bass bar will not sound good.
With no point of reference, it is hard to realize the size of that plate: so here is a standard violin-sized plate for comparison: A 16-1/2″ viola is pretty big.
I cut the bass bar to the desired shape, using gouges, planes and scrapers.
I know it will be difficult to accomplish the inner edgework after the plate is installed, so I always do that first. I also trim and shape the linings, so that they taper smoothly into the ribs.
Installing the Front Plate
I dry-clamped the plate to the Garland, and then, using a thin palette knife, slipped hot hide glue (on the thin side, for easy removal if needed) into the unclamped areas and immediately applied padded spool clamps totightly hold the plate until the glue could dry. Then I removed the first few clamps and inserted glue there, and reclamped. My wife thinks the instrument looks as though it is wearing hair-curlers at this point. 🙂
And that is where the instrument rests for tonight.