16-1/2″ 5-string Viola Varnish Sequence

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:

    1. a tanning treatment,
    2. a mineral ground treatment,
    3. a sealer, to lock the mineral ground in place, and
    4. 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.

Tanned front of 16-1/2" 5-string viola
Tanned front side of the 16-1/2″ five-string Viola.

 

16-1/2" Five String Viola tanned back side.
Tanned back side of the same instrument.

Mineral Ground:

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.

Mineral ground drying on 16-1/2" Five-String Viola.
Mineral ground drying on 16-1/2″ 5-string Viola. (5-string bass beginning in background.)

 

Mineral Ground is dry on the 16-1/2" Five-String Viola.
Mineral Ground is dry. I will sand off any excess mineral, and then apply the sealer.

 

Sealer

16-1/2" Five-String Viola with Sealer coat, front view.
Sealer coat, front view.

 

16-1/2" Five-String Viola with Sealer coat, back view.
Sealer coat, back view.

 

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.

Varnish Beginning

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.

16-1/2" Five-String Viola with Two coats of yellow varnish, side and front view.
Two coats of yellow varnish, side and front view.

 

16-1/2" Five-String Viola with Two coats of yellow varnish, back view.
Two coats of yellow varnish, back view.

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.

 

Thanks for looking.

 

Final woodwork on 5-string 16-1/2″ Viola

Last “woodwork” tasks on the 16-1/2″ five-string Viola:

Last time, we finished up with the neck set, and the corpus closed, but all the edgework (and final shaping of the neck heel, etc.) left to be done.

Closed corpus of the 16-1/2" five-string Viola: purfling weave sketched, heel/button need carving.
Closed corpus, purfling weave sketched, heel/button need carving.

 

Carving the heel/button combination

The neck heel and the back button, together, make up the majority of the strength of the neck-joint. I once had a cello come in for repair, fully up to tension, but “something was loose.” Yeah, the ONLY glue still holding in the neck-joint was the glue between the neck heel and back button! I removed the neck, cleaned out the old glue, and re-glued the entire joint: but I never forgot that the heel/button connection alone had held the entire load of the string tension! So I make certain that this joint is perfect, and the two are carved as one piece after gluing.

There is also a specific measurement from the center of the neck-heel curve to the top edge of each side of the front plate where it joins the back: in violas, I shoot for exactly 27mm.

Heel and button carved on the 16-1/2" five-string Viola: ready to begin purfling.
Heel and button carved: ready to begin purfling. I have laid out the purfling and incised it.

 

Purfling

I used to struggle with cutting the purfling slot (I still do, but for different reasons) because I was trying to cut the full depth in a single pass, or maybe two. One of my teachers corrected me, saying that the first pass around, with the knife, is just to “darken the lines” left by the marker. Then it is relatively easy for the blade to follow the groove for subsequent fast passes, each making the slice a little deeper. Finally, I use a special tool to pick out the waste wood from between the lines.

Purfling pick with front plate of 16-1/2" five-string Viola.
Purfling-pick with front plate.

One problem I faced with the back plate that I had not noticed so much, on the front plate, even though it had the same issue: This purfling is a little wider than what I usually use, so, in spite of the fact that I marked out the correct width, my pick tools (all of them) are made for the narrower purfling, and they do not readily make the slot the correct width. That meant a lot of going back and widening things just a little bit (0.5 mm, usually.) The European spruce of the front plate is soft, and quite forgiving. The harder European maple back plate does not give at all, so if the slot is too narrow, the strip is not going in, at all.

Another issue is that the purfling weave is on top of a fairly thin portion of the back plate, so I could not cut my slots as deeply as I wanted to. Thus, there was very little wood-support for the purfling, and the pieces were difficult to fit, whereas, around the perimeter, I could cut a slot for the full depth of the purfling strips and achieve full support. Ah, well…that’s life. But there were some joints I am not so happy with.

Anyway, this is how the purfling went:

I cut the center bout slots, first, along with the corners of the 16-1/2" five-string Viola.
I cut the center bout slots, first, along with the corners.

 

The goal is to complete the whole slot before inserting any purfling on the 16-1/2" five-string Viola.
The goal is to complete the whole slot before inserting any purfling. (Notice the shallow purfling-weave slots.)

 

Installing the purfling

As I did on the front plate, I installed the center-bout strips first, dry, and then the rest of the perimeter. I glued the perimeter in completely, before beginning the purfling weaves, themselves.

In the case of the purfling weaves, since the slots were so shallow, I glued each piece as I installed it, then worked on the other end of the instrument while the glue from that piece set up and began to hold.

Outer perimeter complete...working on the purfling weaves for the 16-1/2" five-string Viola.
Outer perimeter complete…working on the weaves.

 

Purfling weave nearly done on the 16-1/2" five-string Viola. Notice that some joints are not as clean as others.
Purfling weave is nearly complete. Notice that some joints are not as clean as others.

 

Completed purfling weave on the 16-1/2" five-string Viola: still needs to be planed flush.
Completed purfling weave: still needs to be planed flush.

 

Completed purfling weave on the 16-1/2" five-string Viola...warts and all.
Completed purfling weave…”warts and all.” I may elect to go back and improve things a little. (Probably not.)
The other weave on the 16-1/2" five-string Viola turned out a little better.
The other weave turned out a little better.

The Channel

Once the purfling is all in place, and planed flush, it is time to carve the “channel.” This is a slight “ditch” that runs all the way around the perimeter: the bottom of the “ditch” is usually at the purfling, while the outer edge of the ditch ends exactly at a line called the “crest,” which is about 40% of the distance in, from the outer edge of the plate to the outer edge of the purfling. The inner edge of the “ditch”  will be planed and scraped back to “fair” into the surface of the arching, without any lumps or hollows.

Notice the pencil-line marking the crest of the edge on the 16-1/2" five-string Viola.
Notice the pencil-line “crest”, between the purfling and the plate-edge.

 

Edgework

Finally, after all the surface of the plate is correct, I plane, scrape and sand the edges themselves, so that the outer curve of the plate edge perfectly meets the inner curve of the channel, all the way around the plate.

In this case, I did not take the picture until after I had completed the next step, which was to wet the whole structure down with water, in order to deliberately raise the grain, so that any imperfections, or compressed areas, will rise up and be seen…and subsequently, be scraped and sanded flush again. All this to say, please understand the “rough” surface of all the wood.

Edgework of the 16-1/2" five-string Viola complete, but still rough with raised grain.
Edgework complete, but still rough with raised grain.

 

So…that means the whole instrument is now complete, minus the varnish prep-work, and the actual varnish and set-up!

16-1/2" five-string Viola Front ready for varnish.
Front ready for varnish.

 

16-1/2" five-string Viola Side ready for varnish.
Side ready for varnish.

 

16-1/2" five-string Viola Back ready for varnish.
Back ready for varnish.

 

Varnish Sequence

I will post the varnish sequence as it occurs, but, for now, know that the sequence will include at least two “wet-it-down, let-it-dry, and scrape/sand-it-smooth” iterations. The idea is to produce a surface that will no longer respond to moisture by raising the grain. This is particularly important on the handle portion of the neck, where the moisture from players’ hands will certainly be in contact with the wood, every time the instrument is played. But, under the varnish, the slightest discontinuity will become glaringly obvious, so that is important as well.

After the wood is smooth, there will be:

    1. a tanning treatment,
    2. a mineral ground treatment,
    3. a sealer, to lock the mineral ground in place, and
    4. finally, the varnish itself in a series of 6-12 coats, depending on color.

 

Enough for today.

 

Thanks for looking.

 

 

 

 

 

16-1/2″ 5-string Viola nearing completion

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:

16-1/2" Five string viola Arching nearly complete; Neck nearly complete.
Arching nearly complete; Neck nearly complete.

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:

    1. Prepare the neck heel– angles and dimensions all correct. Heel absolutely flat, all mating surfaces absolutely smooth.
    2. 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.
    3. Check all measurements with every single change:
      1. how does the centerline of the neck fit, relative to the centerline of the corpus?
      2. how does the transverse level of the neck match the level of the corpus?
      3. how does the pitch (front-to-back) angle compare to what is correct?
      4. how does the distance between the nut line and the top edge of the front plate compare with the correct distance?
      5. how does the height of the lower edge of the fingerboard above the edge of the front plate match the correct height?
    4. 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.
    5. Let it dry!
16-1/2" Five String Viola Neck set complete!
Neck set complete!

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.”

Beginning graduation of the back plate of the 16-1/2" five-string Viola.
Beginning graduation of the back plate.

 

Calibration of back plate of the 16-1/2" five-string Viola begun: making thickness "dots."
Calibration of “dots’ begun: circled dots are already correct. Others need carving out.

 

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:

Dots completed on the 16-1/2" five-string Viola, and ready to be connected, using a plane.
Dots (front plate) completed and ready to be connected, using a plane.

 

After connecting the dots, the graduation is very nearly complete. I scraped, and checked thicknesses, and scraped some more, until it looked like this:

Shadow line shows curve of completed graduation on the 16-1/2" five-string Viola.
The shadow line shows the curve of completed graduation.

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.

Sketching in the block shapes for the 16-1/2" five-string Viola.
Sketching 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.

Neck heel cut off flush with the neck block in the 16-1/2" five-string Viola.
Neck-heel cut off flush with the neck block.

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 very careful until the back plate is glued on, making the structure rigid and strong again.

Mold is out! Preparing to shape the blocks in the 16-1/2" five-string Viola.
Mold is out! Preparing to shape the blocks.

 

No mold means no support! Be very careful! The 16-1/2" five-string Viola is very fragile at this point.
No mold means no support! Be very careful!

The next photo is from an earlier instrument, because I forgot to take a picture of the shaped blocks in this instrument:

The general shape of the finished blocks (earlier five-string viola.)
The general shape of the finished blocks (earlier 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.

16-1/2" Five String Viola Closed Corpus, with bass in the background. Glove is padding.
Closed Corpus, with bass in the background. (Gotta get going on that double bass again!)

 

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.

Neck heel and back button of 16-1/2" five-string Viola awaiting final shaping. Planned purfling weave sketched in.
Neck-heel and back button awaiting final shaping. Planned purfling-weave sketched in.

 

But I will leave those steps for a later post…this one is already too long. (sorry…)

 

Thanks for looking.

 

Progress moving forward!

Making advances on the 16-1/2″ 5-String Viola.

Status as of my last post:

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:

16-1/2" five-string Viola garland with top plate installed, back plate traced, and scroll begun.
Garland with top plate installed, back plate traced, and scroll begun.

 

Scroll Work

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.

16-1/2" five-string Viola scroll and pegbox essentially complete.
Scroll and pegbox essentially complete. Ready to temporarily attach the fingerboard.

 

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:

16-1/2" five-string Viola back arching nearly complete, neck and fingerboard joined.
Back arching nearly complete, neck and fingerboard joined.

 

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.)

Next Steps

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.

Thanks for looking.

 

More Progress on the 16-1/2″ Five-String Viola

Progress on the 16-1/2″ five-string Viola

Beginning the plates

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:

Remaining scribe-line for edge-thickness on the 16-1/2" five-string Viola.
Remaining scribe-line for edge-thickness. I plane down to the line all around, eventually.

 

Line beginning to disappear on the edge of the 16-1/2" five-string Viola.
Line beginning to disappear.

 

Arching complete on the front plate of the 16-1/2" five-string Viola.
Arching complete.

 

Arching complete and f-holes laid out for the 16-1/2" five-string Viola.
Arching complete and f-holes laid out.

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.

F-holes laid out and incised deeply on the front plate of the 16-1/2" five-string Viola.
F-holes laid out and incised deeply.

Graduation

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.

beginning to carve the interior of the front plate of the 16-1/2" five-string Viola.
Beginning to carve the interior for thickness graduation.

 

Carving away the waste wood from the interior of the 16-1/2" five-string Viola.
Carving away all this waste wood produces a lot of shavings. Fortunately, we heat our home with wood, and the shavings are great for starting the morning fire. 🙂

 

Carving thickness "dots" for the front plate of the 16-1/2" five-string Viola.
Once I am getting close, I carve “dots,” calibrated to specified thicknesses.

 

Connecting the thickness "dots" on the front plate of the 16-1/2" five-string Viola, by planing.
“Connecting the dots,” using a finger plane.

 

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.

f-hole cutter, boring the "eyes" of the f-holes on the 16-1/2" five-string Viola.
I use an f-hole cutter to open the upper and lower “eyes” of the f-holes.

 

Ready to cut out the stems of the f-holes on the 16-1/2" five-string Viola.
Ready to cut out the stems of the f-holes. (Earlier instrument…I forgot to take pictures…)

 

Bass Bar

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.

Bass bar fitted, glued and clamped, in the 16-1/2" five-string Viola front plate.
Bass bar fitted, glued and clamped.

 

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.

Size comparison with violin plate and bassbar: 16-1/2" five-string Viola compared to a violin.
Size comparison with violin plate and bass bar.

 

Bass bar glued into the 16-1/2" five-string Viola, and ready for trimming to shape.
Bass bar glued, and ready for trimming to shape.

 

Proposed shape of completed bass bar in the 16-1/2" five-string Viola.
Proposed shape of the completed bass bar.

 

I cut the bass bar to the desired shape, using gouges, planes and scrapers.

Completed bass bar in the 16-1/2" five-string Viola.
Completed bass bar.

 

Another size comparison between the 16-1/2" five-string Viola and a violin.
Another size comparison. Same violin plate.

 

Inner Edgework

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 to tightly 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. 🙂

Front plate of the 16-1/2" five-string Viola installed, glued and clamped to the garland.
Front plate installed, glued and clamped.

 

And that is where the instrument rests for tonight.

 

Thanks for looking.

16-1/2″ Five-String Viola Beginning

16-1/2″ 5-string Viola on the way!

New Project!

This is the first large 5-string viola I have made. So far, most players have been quite firm about wanting the same scale length as a violin…and an instrument that will fit in their fiddle case. So that is what I have mostly made. But lately, there seems to have been an increased interest in five-string violas. Some were interested specifically in a smaller viola (hence the current, nearly completed 5-string 15″ Viola,) but more recently, there were two players who were really interested in a large 5-string viola. A 16-1/2″ Viola with a high E string.

So… here we go! I already had European Maple and Spruce billets set aside from earlier “shopping trips,” and everything else that I needed to build a big viola. All I had to do was to finish the instruments already on the bench! They are now out of the way, except for completing the varnish and final set-up of the 15″ 5-string viola… so I am good to go. Here are most of the materials, with the plates already bookmatched.

 

Materials for new 5-string Viola.
Materials for new 5-string Viola.

Making, Bending and Installing Ribs

The blocks were already in the mold, and shaped. It was time to start working on ribs. I thinned the ribs to the proper thickness, using a fixture I made for my oscillating spindle sander (one of my few power-tools.) Then I bent each of them to the proper shape, using a hot bending iron.

When I had all six ribs shaped, I installed the two center-bout (often called “C-bout”) ribs, and secured them with hot hide glue and clamps. You can see that clamping to a curved surface is not easy. I held the mold in a small vise, then secured each joint using hot hide glue, cylindrical wooden cauls, and f-style clamps.

Center ribs installed on 16-1/2" five-string Viola.
Center ribs installed on 16-1/2″ five-string Viola.

 

When the glue holding the center-bout ribs was dry,  I trimmed the ends of the ribs, using the spindle sander again, and installed the lower bout ribs. The joint at the center of the instrument, between the lower ribs, has to be pretty close to perfect, as it will always be visible and any discrepancies will be glaringly obvious under the varnish.

Center ribs trimmed to match the curvature of the blocks of the 16-1/2" five-string Viola.
Center ribs trimmed to match the curvature of the blocks.

 

Lower ribs installed on the 16-1/2" five-string Viola.
Lower ribs installed.

 

Finally, I installed the upper ribs. There is no joint between the upper ribs: in fact, they don’t even have to touch. The neck mortise will remove the middle section regardless of how good my joinery is, so I leave a gap there to allow for easy installation of the ribs. (Meaning, I only have to concern myself with how the ribs fit the corner blocks and that they cleanly follow the mold up to the neck block.)

Upper ribs installed on the 16-1/2" five-string Viola.
Upper ribs installed.

 

Making, Bending and Installing Linings

While I was bending ribs, and still had the iron hot, I went ahead and cut and bent a supply of linings. The linings, like the blocks, are made of willow, because I like the way it works. The linings serve to triple the gluing surface of the edges of the ribs, where they contact the plates, as well as strengthening the rib garland.

Linings bent and ready to install on the 16-1/2" five-string Viola.
Linings bent and ready to install.

 

I made a small mortise at the juncture between each rib and each block (24 of them,) and then installed the linings dry, to make certain they fit correctly. Then, one-by-one, I removed each lining, applied hot hide glue to both the rib and the lining, and quickly reinstalled the lining and secured it with a series of small spring-clamps.

Linings installed in the 16-1/2" five-string Viola, with hot hide glue and spring clamps.
Linings with hot hide glue and spring clamps.

 

Tracing the Shape of the Plates

When the glue holding the linings was dry, I removed the clamps and used the spindle sander to trim the ends of the rib corners. I also leveled the front and back of the garland, so that I would be able to trace the shape of the plates.  The European Maple back plate is on the left, and the European Spruce front plate is on the right.  I used a small washer as a spacer, to establish the edge overhang, and a ball-point pen to trace the shapes. You can see that I have begun work on the neck, as well, which is also made of European Maple.

Completed garland, traced plate-shapes, and partially carved neck for the 16-1/2" five-string Viola.
Completed garland, traced plate-shapes, and partially carved neck.

 

The garland is temporarily out of the focus of the work, now, so I hung it up, out of harm’s way, until I am ready to begin installing plates.

Rib garland of the 16-1/2" five-string Viola, completed and set aside for safe-keeping.
Rib garland completed and set aside for safe-keeping.

 

The next step is to actually cut out the plates and begin shaping them into the voice of a Viola. I will let that wait until a later post.

 

Thanks for looking.

 

Purfling, Edgework and Scroll on a 15″ Five-string viola

Purfling the 15″ 5-string Viola

Complete the slots

When I last posted, I had only begun cutting the outer purfling slots (I planned double purfling plus a weave for the back), so the next thing was to complete those slots.

Tools I used to cut the slots for the purfling in the Five-string viola.
Tools I used to cut the slots.

 

Front Purfling slots complete on the 15" Five-string viola.
Front Purfling slots complete.

 

Back purfling slots complete on the 15" Five-string viola.
Back purfling slots complete, including the upper and lower weaves.

 

Inserting and Gluing the purfling

The next step is to insert and glue the purfling in place, using hot hide glue. First I bend the purfling, using a hot iron, then I cut the ends to match the joints where the various sections meet. I insert the pieces dry, to ascertain that they fit, then, one-by-one, I pick the pieces back out and insert hot hide glue into the underlying slot, and quickly re-insert the purfling, forcing it to the bottom of the slot.

Front purfling dry installed on the 15" Five-string viola.
Front purfling dry installed in the Sitka Spruce top plate.

 

Close-up of glued purfling for the 15" Five-string viola, partially trimmed.
Close-up of glued purfling, partially trimmed.

 

Front Purfling glued on the 15" Five-string viola...no edgework done.
Front Purfling glued…no edgework done.

 

Back Purfling glued in place in the 15" Five-string viola.
Back Purfling glued in place.

 

Upper Weave complete on the 15" Five-string viola.
Upper Weave, in heavily spalted Big Leaf Maple back.

 

Lower Weave completed on the 15" Five-string viola back.
Lower Weave. No edgework, yet.

 

So that was the completion of the purfling. Edgework was next, shaping the channel through which both purfling slots will travel, as well as the outer edge and how the channel fairs into the front and back plate curvature. I used gouges, small planes and files, to get the edges to the required shape of a finished instrument.

While all this was happening, I was also getting going on the scroll, pegbox, and neck, but I will save that story for another post.

Beginning the scroll-carving for the 15" Five-string viola.
Beginning the scroll-carving.

 

Thanks for looking.

15″ 5-string Viola Progress

Progress Report for the 15″ Five-string viola:

When I last posted, I had completed the carving of both plates and the garland, but had not begun assembling the corpus.

Bass-Bar

The next step was to install the bass bar. The bass bar is the only fixed, interior brace in violins, violas or cellos. Flatback basses do have some other bracing, but they are a different “branch of the family,” so to speak.  All members of the violin family have a bass bar– a spruce brace, which runs “north-south” at a slight angle, nearly parallel to the centerline of the front plate of the instrument, and just inboard of the bass-side f-hole, so that it supports the bass-side foot of the bridge.  In a five-string instrument, this becomes an even more critical part as the instrument has a broader range and has to have good support on the bass side, as well as the ability to sing in the higher registers.

I first carve the bass bar bottom to exactly fit the inside curve of the front plate, along the correct location, and at the correct angle, then glue and clamp it in place, using hot hide glue and special clamps, padded with cork, so as not to damage the soft spruce of the front plate.

Fitted, glued and clamped bass-bar on a Five-string viola.
Fitted, glued and clamped bass-bar. Still needs to be shaped.

 

Proposed general profile of the bass-bar for a Five-string viola.
Proposed general profile of the bass-bar.

 

Shaping the bass-bar in a Five-string viola, using a finger-plane.
Shaping the bass-bar, using a finger-plane.

 

Completed shaped of finished bass-bar for a Five-string viola.
Completed shape of finished bass-bar.

 

Five-string viola corpus assembly:

Now the plates are ready to be installed. Before doing so, I used a small finger plane and half-round files to shape the edge all the way around on the inner face of each plate, hoping to avoid having to shape it after installation. (I am aware that sometimes adjustments have to be made, so I may have to do some tight-clearance work later on, in spite of this precaution. That’s OK.)

The next step was to install the back plate. This is an older-model mold, or “form,” (my first, in fact, as I mentioned in an earlier post)  so it has some peculiarities, compared to my newer ones: it is a two-part mold, made to collapse, thus easing removal of the mold after installing the first plate. But in later iterations, I moved toward installing the front plate first, and installing the neck before removing the mold.

In this model, originally, I had planned to install the back plate, then remove the mold, and finally install the front plate, after which I could install the neck whenever I was ready to do so. Nowadays I personally find it easier, however, to install the neck before the back plate is in place, because I don’t have to concern myself with the back side of the heel aligning with the back plate button.  (Annnd, it would have been a simple matter of planning, to still do that with this mold, if I had been thinking ahead: just label the front side of the mold as being the side without the screws (which have to be accessible) and you can install the front plate first, then remove the mold after installing the neck; no problem.) However…I wasn’t thinking ahead, and I used the mold exactly as I had originally designed it, so I have no choice, now: I am forced to install the back plate first, remove the mold and then (after shaping the blocks and linings and cleaning the interior of the corpus) install the front plate. So that is what I did. (By the way, in case you are thinking that the shape of the front and back plates are mirror-image of one another, the fact is, they virtually never are exactly mirrored, and are nearly never bilaterally symmetrical even if they were. So the front plate will not fit the back of the mold, and vice-versa.) Ah, well…hindsight, etc.

Here is the back plate, glued in place: the mold is still inside, holding everything rigid. Notice the spalting and curl in the maple back. This is a striking look, and some people love it…others do not.

Back plate of the Five-string viola glued and clamped in place on the garland.
Back plate glued and clamped in place on the garland.

 

After the back plate glue was dry, I removed the mold, shaped the interior blocks and linings, and cleaned up the interior of the corpus, so that it was ready for the front plate to be installed. I also installed the signed and numbered label, marking this as one of my handmade instruments.

Then I clamped the front plate in place, dry, just as I had done with the back plate, removed a few clamps at a time, and used a thin palette-knife to insert hot hide glue between the plate and the blocks and linings. As soon as I had the glue in place, I quickly replaced whatever clamps I had removed, before the glue could gel.

Once the plate was glued and clamped all the way around, I went back around with a blade, and picked out any gelled, cooled hide-glue that had squeezed out of the joint, so as not to have to deal with it later, in the form of hard, jagged chunks of dry hide glue. Then I tightened the clamps a little, and brushed hot water all around the joint, so as to reconstitute any glue that had gelled too soon, and allow the joint to close even more tightly.

Here is the corpus, all glued together.  The next step will be to adjust the overhangs as needed, and lay out the corners so as to begin purfling.

Front plate of the Five-string viola, showing the corpus: assembled, glued and clamped.
Front plate showing: Corpus assembled, glued and clamped.

Beginning Purfling the Five-string viola:

I used to do my purfling before closing the corpus, but I frequently discovered that the rib garland had moved a little, during the removal of the mold…or in some other way, things had changed, and then my plates no longer fit the garland, and I could not change the plates, because I had already installed the purfling…which locks in the shape of the plates, irrevocably (sigh…). So, I began waiting until after the corpus is closed and whatever needed overhang adjustments have been made, and then begin purfling.

I use a two-blade purfling marker to sketch in the location of the twin, parallel cuts needed to make the purfling slot, but I have to sketch the corners in by hand, with a pencil, because the purfling marker will not correctly lay out the corners.

I went ahead and began both the front and the back plates, but got too tired to complete them last night.  (Today was spent getting last-minute things done, as we have heard they are mandating that all Oregonians stay at home, due to the coronavirus scare. Went and bought flour and other groceries, filled the car with gas, and got the snow-tires removed, as that deadline is soon upon us as well.)

One thing about the maple and spruce plates: the spruce is very soft, compared to the maple, but it is tricky to carve, because of that. The winter grains (reeds, they are called) are so much harder than the summer reeds, that the blade has a definite tendency to swerve and follow the grain instead of the line you are trying to follow. The maple is much tougher to cut, because it is hard all over, but it is much easier to follow your lines without digressing.

So, here is what the little viola looks like, today:

Back purfling-slot begun on the Five-string viola--far from finished.
Back purfling-slot begun: the dark strip at the top is the only area where I already picked out the slot.

 

Front purfling-slot begun on the Five-string viola.
Front purfling-slot begun: none of the slot has been picked out.

 

In both cases, the plan is to cut the two incisions, pick out the wood between them, and then dry-fit the purfling strips, before removing them one-by-one and gluing them in place with hot hide glue.

That will be the next post, unless I take a break and carve the scroll. Either way, it is starting to look like a fiddle!

🙂

 

Thanks for looking.

Another 14″ five-string Viola

Experiment that paid off as a Five-string viola!

I had originally begun this little viola ten years ago, wondering what effect it would have to go extra-wide on the lower bouts without changing much else: I was sidetracked with other, more pressing projects, so the little viola sat, partially completed, for ten years. I was somewhat disinclined to complete it, now, because my skills have increased significantly over the intervening years, and I can’t undo some of the “marks of the amateur” which now glare at me accusingly. But, I also felt the need to get some 5-string violas going, and if it didn’t work then I could still toss it out, or whatever…at any rate, it was just an experiment.

I completed the little 5-string viola about the time I completed the recent commission, so I numbered it accordingly, and set it up. It has a great big voice, and is balanced and clear across all five strings! What a surprise!

Accidental Imitation of a famous instrument

I sent pictures to a violist friend, and her immediate response was “A 14” Tertis! Bet that would have made the old boy mad!”

I had heard of Lionel Tertis, and his famous contribution to the viola world…but had never actually seen one of his instruments. So I looked up photos on the internet, and, to my surprise, it really does look like my little fiddle! So, I inadvertently retraced the steps of Mr. Tertis, and produced a fairly powerful little “Tertis-style” 14″ five-string viola! He, of course, was on the other end of the spectrum, trying to achieve a very large, but still playable, viola. (My apologies to the Maestro! I wasn’t being deliberately irreverent!)

🙂

Here are some photos:

14" Five String inadvertently "Tertis-style" Viola
14″ wide-bout 5-string viola front.

 

14" Five String Viola after the tradition of Lionel Tertis...by accident.
14″ wide-bout 5-string viola side.

 

14" Five String Viola after the tradition of Lionel Tertis...by accident.
14″ wide-bout 5-string viola back.

 

The back, ribs and neck are Big Leaf Maple, harvested near my home, and the belly is Sitka Spruce. I used spirit varnish, as usual.

 

Thanks for looking.