Progress report: fiddles for Fall of 2021

Progress Report 8/3/21

Foundational Work For 5-string Fiddles

My last post showed the six “kits” I had built. The post included bookmatching the five-string fiddle plates, cutting the profiles of the Big Leaf Maple necks and scrolls, and cutting appropriate ribs to size. As a result, I ended up with six kits, including bass bar blanks all cut from the same billet of Englemann Spruce, and a big pile of linings ready to bend. ( I thought the linings were willow, but I now suspect may be poplar, instead.)

Five of these front plates ar Englemann Spruce, but one is Douglas Fir. I rarely find Douglas Fir that will work for tonewood, but a friend brought me a pickup-load of firewood,  and I found some that sounds great. (As you can see, I am not a “snob” about where I get my wood. If I need special wood, I buy it, but I frequently use Oregon woods.)

(In case anyone reading this is not aware, I build all my instruments (except the fittings, as a rule) entirely from the raw materials. I make all my molds by hand, and all my templates by hand. I have even made many of my tools. So every instrument is genuinely “handmade in Oregon by Chet Bishop.”) 🙂

materials laid out for 5-string fiddles to be made in Oregon by Chet Bishop
Four of the six assembled “kits.”


I set aside four of the six “kits,” just to get them out of the work area. Then I began work on the remaining two kits.

Fiddles in pieces, waiting to become 5-string fiddles handmade in Oregon by Chet Bishop
Two of the four kits in storage.


Beginning the Builds

The first step after shaping the blocks (last post) is to bend the ribs and linings. Then I can glue the ribs to the prepared blocks, using hot hide glue, and finally glue the linings to the ribs.

I rub a heavy coat of candle-wax (“paraffin” in the US) on the outer rims of my molds. This will prevent a “sneaky” drop of hide-glue from accidentally bonding the ribs to the molds instead of just to the blocks.

(A rib accidentally glued to the mold can be a disaster if I don’t realize my mistake in time. The glue is definitely stronger than the rib. It will destroy the rib, if I don’t catch it early enough to use hot water or steam to release it. But the wax coating pretty much eliminates that problem.)

I used a bending iron and a thin aluminum bending strap, to hand-shape the ribs, and then put them aside in paired sets, with the respective molds for which they are intended.

ribs and linings bent for handmade 5-string fiddle by Chet Bishop in Oregon
Ribs and linings bent and ready to install.

Installing the Ribs

I installed the center-bout ribs first: they can be difficult, so I’m glad they are first. But the real reason they are first, is that the upper and lower ribs will overlap the ends of the center ribs: they do not have a mitered corner, but a lapped corner, which if done correctly, is essentially invisible.

installing ribs on 5-string bluegrass fiddle handmade in Oregon by Chet Bishopribs
A pair of center-bout ribs installed.

I frequently use these “French-style” molds, (flush on the back) which allow me to install the front linings and still easily remove the mold. (Italian-style molds are centered on the ribs…I use that kind, too.)

I used cylindrical clamping cauls of appropriate sizes (dowels, broom-handles…whatever) and f-clamps to quickly secure the rib ends before the hot hide glue gels. If I make a mistake, I can steam the joint loose with a teapot, and do it over, correctly.

After the center-bout ribs dry, I shape the ends of the ribs to match the curvature of the blocks.  Then the upper and lower ribs can be glued to the perfectly-shaped block and rib. Finally, I begin installing the upper and lower ribs.

installing ribs on 5-string fiddle handmade by Chet Bishop in Oregon
First upper rib installed: notice the shaped endes of the center-bout ribs.


Installing ribs in 5-string fiddle handmade in Oregon by Chet Bishop
A pair of matching upper ribs installed.


installed ribs on five-string fiddle handmade in Oregon by Chet Bishop
All the upper and lower ribs installed. (Looking from the back side of the mold.)


ribs installed on two five-string fiddles, handmade in Oregon by Chet Bishop, Luthier.
Two completed rib-sets, ready to be trimmed before adding linings. (Lots of smoke blowing in from the fires this season, making the light kind of red.)


While waiting for glue to dry on the ribs, I laid out the necks so that I will be ready to begin carving them.

Necks for five-string fiddles handmade in Oregon by Chet Bishop, Luthier.
Necks laid out for carving.


After trimming all the corners, so that they look as though the ribs come together as one, I begin installing the linings. I cut a small mortise on each side of each block, flush with the rib, so that the lining will be glued tightly to the rib, and into the block mortise. I secure them all using hot hide glue.

Next, I cut the linings to length, shaping the ends to closely fit the prepared mortises. Then, I coat about 7mm of the edge of the rib, and the entire mating surface of the lining with hot hide-glue and insert the lining into the mortises and push it to the correct level, corresponding to the ribs. Finally, moving rapidly, I secure it with small spring-clamps.

installing linings in five-string fiddles being handmade in Oregon by Chet Bishop
One set of linings fully installed: one to go!


Linings installed in five-string fiddles handmade in Oregon by Chet Bishop
All the front linings installed in both molds.


I made a good deal of progress yesterday, and had hoped to make more progress today, but there were some household repairs that needed to be addressed first; so I didn’t begin working on violins until mid-afternoon.

Tomorrow I will level the fronts of the garlands and trace the front plates… I hope.  🙂


Thanks for looking!

Need More Fiddles!

Failed to Keep Up!

I shipped the last three fiddles I had made and I am left with the “cupboard” looking pretty bare!

This had been a busy year in a lot of other ways, and I have spent a lot of time messing around, trying to build a travel case for the Travel Bass I built last summer. (Without the case, the bass isn’t going anywhere, so I really need to complete it.) Also, the last two fiddles I had made were literally hanging around the house, and so, I wasn’t feeling pressed to build more of them right away.

Sudden Change

But those two fiddles have suddenly found homes. The only two five-string violin-size fiddles I have left are ones I made several years ago: they both play very well, but the ones I am building currently are my best work, and that is what I want to put in players’ hands.

The Plan

So…I decided I had better hit the Lutherie trail in a big way: I took six of my molds (five in the photo, below…the sixth shows up later) and glued the blocks in place, to begin a group of six new fiddles. I plan to select and prepare materials, and match them together into “kits,” so that I know which top plate goes with which back plate…and neck, and ribs, etc.

Then, I plan to begin building them in pairs, but I will always have another pair ready to begin, if things slow down at all.

5-string fiddle molds with blocks and a transparent template.
Five molds with blocks and a transparent template.

The Process:

You have to look closely to see the plexiglass template in the photograph above (and below.) The template is hard to see, but it gives the precise shape I want for the outline of my blocks. I use a ballpoint pen to trace the shape onto the blocks.

Template tracing block shapes for 5-string bluegrass fiddle made by Chet Bishop
I use the template to trace the exact shape I want for my blocks.


Then, I use a saw to roughly cut out the shapes , and an oscillating spindle sander to shape them precisely. I apply wax to the edges of the molds so that an accidental drop of glue can’t bond them to a rib. The ribs are only glued to the blocks and linings, initially…the mold will be removed.

Molds with blocks shaped for 5-string bluegrass fiddle by Chet Bishop
Here are the blocks, shaped and ready for ribs.

Wood Choices

Next, I cut the ribs from wood that match the back and neck, as closely as possible. Usually, I try to get them all out of the same billet of wood. Over the years,  I have harvested some of my wood, myself, or it was given to me by a friend, in log form, and I had someone mill it up for me.  At other times, I have bought other wood from tonewood dealers.

I have used a variety of woods for the back plates: These (below) are all Big Leaf Maple, and I have used a wide variety of other woods; but when I build for classical orchestral instruments, I use only European Maple and Spruce.

I bought the wood (in the pictures below) from Bruce Harvie, of Orcas Island Tonewood Co. That piece of Big leaf maple on the right measures 2″ thick, about 6″ wide, and 16″ long, or more. The large billet allowed me to cut the ribs, neck and two-piece back all from the same billet. I cut up the Englemann Spruce billet on the left  to provide two tops and nine bass-bars.

Wood for 5-string bluegrass fiddles made in Oregon by Chet Bishop.
Englemann Spruce and Big Leaf Maple.


MAple wood for a 5-string bluegrass fiddle made in Oregon by Chet Bishop.
Same piece of Maple…closer view.

Processing the materials:

To begin with, I used a bandsaw to slice off the rib material. Then, I laid out the actual shape I needed for the back and neck. (The traced “shape” visible in the above photo is not my mark: it is just the way tonewood dealers catch the imagination of their customers.) 🙂

When I cut out the back plate shape I had to slice it in half lengthwise, and glue the halves together, to form the back plate.

planing center joint of a back plate for a Chet Bishop five-string fiddle.
Hand-planing the center joint.


Maple back for 5-string bluegrass fiddle made in Oregon by Chet Bishop.
Same billet, made into a back plate blank. The rest became ribs and neck.


Then, I traced out all the neck billets and used a bandsaw to cut them out.

Neck billets for 5-string fiddles made in Oregom by Chet Bishop.
Looks like a “bouquet of fiddle necks.” They will be matched with their respective backs and ribs.


Next, in addition to the work on the heavier components, I sliced ribs from appropriate wood to match the wood of the backs: a darker maple back required darker maple ribs. They will be only 1 mm thick when finished.

Ribs for 5-string fiddle.
I was glad I had rib material that matched the color of the old wood for this fiddle. That back (below) was harvested in September, 1983.


Wood for 5-string fiddle made in Oregon by Chet Bishop
Matching ribs and neck to back wood.


After thinning the ribs, I used a knife to cut the ribs to size.

Wood for ribs for 5-string fiddle made in Oregon by Chet Bishop
Each set of ribs requires three lengths for upper, center and lower bouts.

Douglas Fir

I usually build the top plates of spruce (Sitka, Englemann, European or other species.) Sometimes (rarely) I will use other woods: this one is Douglas Fir. Otto Erdesz used Douglas fir for front plates on many instruments. So far, I have only used Douglas Fir once, but it turned out to be an excellent fiddle, so  I am doing it again. 🙂

Wood Kit for a 5-string bluegrass fiddle handmade in Oregon by Chet Bishop.
A Douglas Fir top plate with a Big Leaf Maple back, neck and ribs.


And finally, I see the kits beginning to emerge!

Materials for 5-string fiddles handmade in Oregon by Chet Bishop
These Kits will help me keep focused and encouraged about building the six new fiddles.


I will try to provide updates and to post progress reports.


Thanks for looking.

New Five-String Fiddle Completed!

Five-String Fiddle from the Vallery Tree

The Beginning:

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 exactly where: all I can say is that I bought it from a local wood dealer.

Early stage Oregon five string bluegrass fiddle by Chet Bishop
Early stage… at this point there was a long way to go!


Eventually, I had the corpus (body) completed and had begun working on the neck and scroll. Additionally, arthritis was plaguing me a little, so it was slow progress.

handmade Oregon 5-string fiddle in progress
Completed corpus with partially carved scroll and neck.


hand carved five string fiddle scroll for oregon 5-string fiddle
Nearly-completed scroll joined to fingerboard, for final shaping as a unit.


completed scroll and neck assembly with fingerboard ready for installation on Oregon five-string fiddle
Completed neck assembly, ready for “neck-set.”


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.

Beginning the neck mortise on an Oregon handmade 5-string fiddle by Chet Bishop
Beginning the neck-mortise into which the neck heel will be set.


Final Assembly

After the neck mortise is completed, so 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 then I quickly ram the neck into place. Then, I checked all measurements one last time and clamped it with a single clamp at the heel.

neck set completed on a handmade oregon 5-string fiddle by Chet Bishop
Successful Neck-Set! (The button and heel still need to be trimmed…)


back view neck-set handmade Oregon 5-string fiddle by Chet Bishop
Back view


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.

five string fiddle handmade by Chet Bishop in Oregon
First coat of (yellow) varnish. The Spruce shows the yellow strongly.


varnishing a 5-string bluegrass fiddle handmade in Oregon by Chet Bishop
Back view: the Maple was darker to begin with, so the yellow is not as obvious.

Final Set-up

Finally, the instrument was fully varnished and set-up:

Oregon handmade five-string bluegrass fiddle by Chet Bishop
Front View of the completed instrument.


Oregon Bluegrass five-string fiddle, handmade by Chet Bishop
Side View:


Oregon five-string bluegrass fiddle, handmade by Chet Bishop
Back view.  (I love that grain!)


The Verdict:

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.


Thanks for looking!



New Handmade Five String Fiddle

fiddle with sealer

Handmade Oregon Five-String Fiddle in Progess!

Just an update: 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: It promises to be a great fiddle! (And, it did!)

front with sealer
Front view with sealer. I must have moved just a little, as I see it is blurred a little. But the color is accurate.


Treble side of five-string bluegrass fiddle, with sealer
Treble side, with sealer. I think those ribs are going to be beautiful!


Bass side of handmade Oregon 5-string fiddle with sealer.
Bass side, with sealer. Looks even nicer on this side!


Back view of Oregon Big Leaf Maple five-string fiddle with sealer.
Back view, with sealer. I like this best of all.


I always hang the fiddles in the dining room to dry, since we heat with wood, and that is where the woodstove is. The room stays warm, especially up near the ceiling.

Back of oregon five-string blurgrass fiddle with sealer drying.
Hanging in the dining room to allow the sealer to dry.


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.

Thanks for looking.

Newest Development

five string viola

15″ Five String Viola in North Carolina!

A shop in Charlotte, NC has agreed to take one of my fiddles on consignment.

The shop is called “The Violin Shoppe” and is a pretty important outlet in that area for stringed instruments, so I am thrilled to be represented there.

One of the owners, Glen Alexander, is a great fiddler, and demonstrated the posiblities offered by my little five-string viola, on his facebook page as well as on YouTube.

Here is the YouTube video: Glen Alexander putting my 5-string fiddle through its paces.

I’m gratified to see an Oregon Five-string fiddle, there, and to hear him play it!

Meanwhile, I have others on the way. 🙂

Thanks for looking!


First Complaint!

Nice Problem to have!

Addictive Fiddle!

I got a text message from Andy Pastor, stating his only complaint so far, regarding the new five-string fiddle he bought last week:

He isn’t getting enough sleep!

He finds that fiddle to be utterly addictive, and has been staying up ’til midnight playing the thing, even when he knows he has to get up and go to work in the morning! 🙂

Great problem to have!

Here is Andy, playing his new fiddle:

Playing the new 5-string Fiddle
Happy Fiddler!


And here are two sound clips (actually recorded in his bathroom where there are high, vaulted ceilings, producing a bit of an echo-effect…which he likes. )


First one is “St. Ann’s Reel” Second is “Arkansas Traveler.”


Thanks for looking!

5-string fiddle from bass back

5-string Fiddle Back from Bass Back Scrap!

I don’t like wasting tonewood!

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.

Five-string fiddle back cut from the scrap left from a 5-string double bass back.

Arching the Plate

Five string fiddle begun, with back and neck from scrap from a 5-string double bass back.
Five string fiddle begun, with back and neck from scrap from a 5-string double bass back.


I really like the look of the Oregon Big Leaf Maple back wood. I enjoyed arching the plate.

Five-string fiddle back arching nearly complete.
Five-string fiddle back arching nearly complete. It is sitting on the five-string double bass garland whose back provided the scrap for the fiddle-back.

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.

Five-string fiddle back with purfling slots incised and ready to complete.
Five-string fiddle back with purfling slots incised and ready to complete.

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.


Thanks for looking.

Beginning the Plates

Beginning the Plates

Bookmatching the Plates

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.

Sitka Spruce front plate halves for the five-string double bass.
Sitka Spruce front plate halves for the five-string double bass.
Rough shape of five-string double bass back plate, and template for the neck.
Rough shape of the five-string double bass back plate, with the template for the neck. The neck was cut out of the scrap from the back.


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.

Sitka spruce front plate for five-string double bass, bookmatched and ready to glue.
Sitka spruce front plate for five-string double bass, bookmatched, and ready to glue.


Front and back plates for five-string double bass, bookmatched and ready to trace shapes.
Front and back plates, bookmatched, and ready to trace shapes.

Tracing the plates

Sitka spruce front plate for five-string double bass, ready to trace the shape.
Sitka spruce front plate, ready to trace the shape.


Ready to trace the shape of the front plate of the five-string double bass.
Ready to trace the shape of the garland onto the front plate.


Using a pipe spacer to trace the shape of the five-string double bass front plate.
Using a pipe spacer to trace the shape of the garland onto the Front plate.


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!

Cutting out the completed shape of the front plate for the five-string double bass.
Cutting out the completed shape of the front plate. I am not attempting to cut exactly to the lines. I will correct to the lines, after the arching has been completed.


Cutting is complete: the front plate for the five-string double bass is ready for arching.
Inside view: the cutting is complete: the front plate is ready for arching.


Outside view of the front plate for the 5-string double bass.
Outside view of the front plate.

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.

Edge-thickness scribed into front plate for the 5-string double bass.
Edge-thickness scribed into front plate.


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.

Front plate for the 5-string double bass secured in a work cradle.
Front plate secured in a work cradle.


Tools for arching the five-string double bass.
Tools for arching: cradle, gouges and planes.


Sculpting the front plate arch for a five-string double bass.
Sculpting the front plate arch.


five string double bass arching in progress.
Front plate arching in progress!


Planing the arching surface smooth on a 5-string double bass.
Planing the arching surface smooth.


Planes used to shape the 5-string double bass.
Some of the planes used to shape the bass.


Shadow line defining the longitudinal arching shape of the 5-string double bass.
Shadow line defining the longitudinal arching shape.


Transverse arching shape of the 5-string double bass.
Transverse arching shape.


Arching for the 5-string double bass nearing completion.
Arching nearing completion.


Arching and outline completed for the 5-string double bass.
Arching and outline completed.


Time to lay out the F-holes!

F-holes laid out for 5-string double bass.
F-holes laid out, incised, and inked.

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.

Ready to carve the front plate graduations of the five-string double bass.
Ready to carve the front plate graduations.

But…I will leave that post for another day.

Thanks for looking.


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.



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.


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.