Upon that initial string-up, it's true that the viola played more or less like a viola. But the string action was very high. I had not effectively estimated the final neck angle, although now I believe I know how to do that for next time. The bridge had to be trimmed by about 5mm across the board, in order to bring the strings to an appropriate height from the end of the fingerboard:
But the neck really is on straight:
At least within half a degree or so, which is enough to avoid problems. I'll call it a win.
Anyway, that first stringup was only partially successful, because I had followed Partch's advice from Genesis of a Music. He said to use cello strings for the lower G-D-A, and either a violin "first or second" string at double length, or a guitar "monofilament nylon" string, for the E. I have guitar strings around, so I chose the latter... and it was awful. I don't know if guitar strings were made differently in the 1940s-70s, but no matter how much rosin I used, the bow just couldn't make the string speak, plus the tension was alarmingly low. Eventually, I gave up on it; and rather than following his other advice, and locating a specialty extra-long violin string, I just ordered a high E string for a 5-string cello. I spent more on the one string than I had on the actual viola body (not counting the cello parts), but that string sounds great and plays with no issue.
I ended up with strings from 3 different sets of 3 different gauges and ages, but I like 'em. I lucked out and ended up with warmer/duller strings for the lower two, and brighter ones for the top. And I should maybe have predicted this, but due to the fact that the scale length is about that of a 1/6-size cello, and I used normal cello strings and tuned them to cello pitch, the overall string tension is nice and low. It's comfortable to play and doesn't affect the volume much that I can tell. It also makes me feel safe about my glue joints. If I make another one of these instruments, I believe I can safely use a scarf joint for the composite neck and omit both of the pins.
OK, now that I fixed the action and got the correct strings, and there's nothing else to be done in terms of increasing the general playability, it was time to finish out the neck with varnish. I came into this with trepidation, because violin varnish has this whole mystical aura around it (they even made a movie about it), but it turns out: you can just use shellac, and it will come out fine.
This picture was about halfway through my process, and honestly I could have stopped there. But what I wanted was a) a dark finish around the heel; and b) a satin, smooth-feeling, non-glossy finish on the surface that I'd be touching. Here's my whole process:
I sanded everything with 150, then 220, then 320-grit paper.
I used a Minwax "Red Oak" penetrating stain on the bits that I wanted to darken, and sanded the boundary to a gradient. That sucked and looked awful. The glue around the shims and spacers didn't absorb any stain (predictably), so it just enhanced the cobbled-together look of it.
I added a coat of Zinsser "Amber" shellac, and that looked pretty good.
I sanded the shellac gently with 220-grit, and decided to put some black on the heel, using what I had on hand (Minwax gel stain). Because it would be between layers of shellac, rather than underneath, it apparently counts as a "glaze," and people apparently sometimes do that on purpose.
A word on blackening: it's really great to make things look presentable. When I worked in a bronze sculpture foundry, we had a range of patinas that we'd put on the final artworks. When the patina was going to be light, we needed to take a few extra steps preparing the metal surface. But when the patina would be black, those extra steps were sometimes unnecessary, because the difference would be invisible. I wouldn't go so far as to say that black can cover up shitty work--certainly not in that shop, which had a great ethic.
But outside of a professional situation, yeah, it can cover up certain mistakes.
5. I put on another layer of amber shellac. That's where the photo stands above.
That looked great, but you can see that it's still pretty glossy and shows a lot of brush marks. I wanted something that would feel very smooth, and blend with the finish of the rest of the instrument, which is not that glossy. So, after looking it up, it turns out there's a very simple and effective way to do this, called "rubbing it out." (Ha ha ha.) Here's the relevant link: http://www.woodwrecker.com/woodworking/how-to/shellacrubout.shtml
I used fine and then extra-fine steel wool, and lubricated the process with Skidmore's Restoration Cream. Cannot recommend this cream more highly for basically any application: it is incredibly easy to use, idiot-proof, and a little goes a long way.
Unfortunately, I was over-enthusiastic--I rubbed the middle of the neck almost back to the bare wood, which was fine, but I also kept taking off bits of the black glaze near the heel. So after various unsuccessful retouchings with the gel stain and spot applications of shellac, I gave up and just colored in the spots where I'd worn off the black with permanent marker. A little buffing with a paper towel to blend, and you literally can't tell they're there.
[photo of where it is now]
If I were doing this again, I'd use the dark gel stain on the bare wood, and not mess around with a glaze! Or better yet, I wouldn't have any glue on the heel in the first place, because it would be a single solid piece without shims or spacers, so I could use a normal penetrating stain without worrying about uneven absorption. But anyway, this ended up looking good from distances further than about 6 inches, so I am content.
Next: I decided on a custom 32-tone subset of Partch's 43-tone pitch collection, then mapped out what an octave of this would look like on each string. I assigned colors more or less according to Partch's scheme for the Chromelodeon, but because there were a lot of septimal intervals and I didn't care to distinguish 3-limit from 9-limit, I assigned Partch's 7-limit green to the 7-Utonal intervals, and switched his 9-limit blue to 7-Otonal intervals.
Some of them I considered to be more "composite" in identity, so I used two colors. I could have done more of this, but didn't feel the need to be rigorously systematic. The fretboards of his Adapted Guitars and the keyboard of the Chromelodeon have color-coding for both Identity and Odentity on every ratio, not to mention they write the ratio in number form as well, but that would have been very crowded in this constricted visual area.
The next step--instead of laboriously calculating every single ratio position by hand, although Partch does provide instructions for how to do this in Genesis of a Music for the martyrs among us--was to go to http://www.ekips.org/tools/guitar/fretfind2d/ and punch in the pitch collection in Scala format. This gave me "fret" positions for each individual string. It still took quite a while to mark them all, with about 200 or so to deal with (including selected pitches from the 2nd octave), but this was a reasonable activity for Election Night.
The yellow and purple all needed a base coat of white in order to show up against the rosewood, and this was achieved using humble White-Out. If I had used white nail polish for that, the two layers would make the lacquer too high of a bump; my goal was to use a single layer of nail polish for every mark. Many tests on a scrap piece from the trimmed cello fingerboard were required to come to these conclusions.
The above picture should communicate incredible anxiety.
A great deal of mess and stickiness later, I can tell you that your method for applying the nail polish accurately should involve using the brush from the bottle to apply the polish to another, finer and stiffer brush, and then painting it on the fingerboard. Once it dries and cures for a whole day, you can actually cut off bits of your lacquer (carefully!) with a sharp chisel, to correct any remaining blobbiness. Anyway, here's the purple and yellow; I got Klimt vibes from this subset of colors.
Once all colors were applied, and had cured to hardness, I sanded them very lightly to remove the worst of the peaks, then touched them up where necessary. Throughout this whole thing, I was worried that the nail polish--which is really just pigmented nitrocellulose--would be too fragile for repeated string contact. So I ultimately decided to treat the fingerboard the same way as I had the back of the neck: coat it in a few layers of shellac, then rub it back to a satin finish. So I applied three very thin layers of Zinsser Clear shellac (not Amber), lightly sanding them in between, and rubbed the last layer back very gently with the fine steel wool and the Skidmore's cream. The final appearance of the finish is very similar to the look of bare wood that's simply been oiled (which is a common treatment for, at least, guitar fingerboards), and comes with the added benefit of a bit of protection on top of the nail polish. I'm honestly pleased with it.
N.B.: Cheap viola cases are just styrofoam with fabric glued on, so you can rip off the fabric, cut the styrofoam to accommodate the profile of your newly butchered instrument, and then just glue the fabric back on. Because the fabric is inevitably going to be polyester, which is plastic, you can use superglue to attach it instantly and very effectively to the styrofoam.
I've sent this instrument to my friend, who is a real luthier, so she can fit the cello pegs into the pegbox for me. I could do that part myself, but a) the tools are specialized and too expensive, and b) frankly I'd rather not risk any more improvised woodworking! There's one more article forthcoming: Illustrated instructions on how to make an Adapted Viola in a smart and somewhat easier way, instead of a way riddled with redundancies and mistakes. This takes into account everything I've learned up to now, and will be geared toward general handypersons rather than actual luthiers (who would have their own ideas of how to go about it, which are unquestionably better and more correct than mine). There will also be videos of how the thing sounds! P.S.- I was going to talk about the fine tuners and the split on the lower bout. Well, in a nutshell, I had to cannibalize two sets of fine tuners because the set on my original viola had some missing and broken parts. And the split couldn't be joined; I eventually figured out that it had been badly repaired in the past (probably by a beleaguered and somewhat handy parent). The split was originally worse, and the rib had been reglued to the back. But this was done slightly askew, so one part of it either opened back up, or had never closed, and the repairperson had attempted to fill that gap with glue (with only partial success). So rather than take off the entire back and restart, I just glued some slivers of softwood into the gap to ensure it won't buzz or open up any further. And who's going to see?