Michael Darnton Violin Maker

Michael Darnton is a violin maker, restorer, writer and teacher who lives in Chicago...

More Ground Samples

more varnish and ground tests

In the last year my sample set has grown to about 40 tests. I don’t feel like I’ve solved anything, but from the samples, and my observations of old instruments, both in my hand and through the microscope, have given me a full set of criteria that a nice varnish ground needs to meet. At the top of the list are two things: sparkling wood fibers when lit from any direction, and maximum transparency–the ability for the microscope to see down through layers of wood cells into lower layers, which depends on very transparent wood structure. On older Cremonese violins that is much more the case than on anything new that I’ve seen.

Grinding Pigments

grinding tools

I’ve often used home-brewed pigments for varnish colors. When they’re finished, they are clumped, and sometimes gritty, in large pieces. To put them into varnish, one first needs to grind them to a fine powder.

When I worked at Bein and Fushi there wasn’t a lot of interest in raw pigments in the art world, so we had to look around to find dry pigments and the tools for grinding them. The hardest thing to get was a muller. Mullers look like upside-down mushrooms with flat tops, and are used against a piece of ground glass to break up pigment clumps and disperse them into varnish (or oil, if you’re making oil colors). The real grinding is done with a mortar and pestle: a muller isn’t a grinding tool as much as a mixing one, to make sure that every particle of pigment gets wetted with solvent or oil. [factoid: glass mullers show up on airport x-rays as completely opaque, and when the inspectors pull them out of your luggage, they still don’t have any idea what they’re looking at, of course…  which reminds me of the time I tried to take a chinrest key into a federal courthouse.]

The first one was so hard to find, that for a while after that I went hog-wild buying them whenever I saw them. They turned out to be easier to find in England, so I came back from several trips with more of them (I was particularly pleased by the little ones with knob handles which came from a wonderful artist’s store near the British Museum in London, Cornellisen’s –if you ever go to London, put it on your list of places to visit. Unlike the US where the exterior may not be mirrored inside, the inside of Cornellisen’s is even better than the facade).

I have more than the ones in the photo. The lean one in the back is the first one. The steel “muller” is actually a meat pounder I bought in a cooking store. I haven’t ever tried it, but for $6, I couldn’t resist. The big one in the front was a going-away present from the guys in the B&F shop, and has my name, all their names, and some other things sand-blasted into it (you can read “CHICAGO MICHAEL” on the top of the handle).

Mortars and pestles, which are necessary if you’re making pigments from scratch, but not always if using commercially-made ones, are easier to find, of course, so I have a variety of sizes, and one that’s just for a single one of my home made pigments that tends to stain everything it touches.

In Renaissance art studios, grinding pigments was childs’ work, and one of the primary jobs of the very young apprentices. It doesn’t take any skill, just lots of patience and time.

Old Pegs

old French pegs

A friend pulled these out of an old violin, and knowing I was interested in this kind of stuff, sent them to me. They’re violin pegs that probably predate 1800, and are maybe as old as 1750. (Notice that one peg doesn’t match–a later replacement, probably.) Eric Meyer, a great fittings maker on the west coast, tells me that they’re probably French, and, based on the number of them that he’s seen (that is: many), they were probably being commercially produced and distributed.

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A Nearly-Perfect f-hole

Amati f-hole

This f-hole is on a Brothers Amati cello dated around 1615. It’s one of the most beautiful I’ve seen and is perfect in execution. I’ve used it on a cello, and reduced it to fit on a violin, and a violino piccolo. In each case, when it’s the right size, it superimposes over the original model’s 4/4 and piccolo f-holes precisely, with no changes. That’s something would not have thought would happen; usually parts between violin family instruments don’t transfer well with a simple percentage change.

It’s All In the Details

People who aren’t intimate with violins don’t have to consider all of the things a maker has to. There are all sorts of details on a violin that have to be done in some intentional way. Not necessarily one way… I don’t mean that. I mean that when you have to do them, you find yourself wondering exactly which choice of the many you should make.

end of the rib

The cut off ends of the ribs at the corners are an example. There’s a definite thickness there; the c-bout rib feathers off to nothing on the inside of the joint (which is a miter, like on the corner of a picture frame), but the outer rib overlaps that and has about 1mm of thickness. You can cut the ends off to mimic the tip of the corner of the top and back (that’s the way that many people find natural, that’s often taught in violin making schools). Some makers in the past trimmed down the outer rib to form a sharp point; that’s logical, but fragile. Makers who taught themselves, and schools that put clamps on the ends of the rib when they glued the rib tips together, often bring both ribs up to the end full thickness, 2mm, with the joint in the center. If they were looking at good violins, they might have subsequently thinned both ribs so that the whole width of the end was 1mm. Some very obscure schools brought the inside, c-bout, rib out to the end, and feathered the outer one, so the (invisible) joint is at the outside of the end of the corner.

The corner in my drawing is the way that 17th century Cremonese makers did it: they cut the end of the (outer) exposed rib off square, so that it doesn’t match the end of the corners of the top and back. It doesn’t make a whole lot of visual sense, in context, but it’s the strongest way to make the tip, so that it doesn’t quickly wear. Guarneri del Gesu, with his sometimes very long corners backed up by blunt endings on the corner blocks that didn’t reach far enough out to give much support, often carried the outer rib out past the inner one a mm or two, by itself, and then finished it off square.

There’s lots to think about for just the end of a rib, and yet virtually everything you see on a violin has been similarly considered, calculated and designed to give a particular effect.

A Really Baroque Bridge

I hope the friend who created this drawing of a very grumpy prototype of a baroque bridge will not mind if I share it with you:

Andres' baroque bridge

More Varnish Texture

German violin texture

This one’s interesting mainly because of its lack of great age: it’s from 1944, made in Hamburg, Germany; not a time and place you see many violins from. Usually I would associate this type of mud-crack surface with a soft varnish that’s been overcoated with something much harder (violating the painter’s fat over lean rule), where expansion and contraction of the softer underlayer has caused the over coat to break up gracelessly the way ice breaks up on water, but I’m pretty sure this particular violin has nothing over the original varnish.

In real life the surface of this violin looks leathery; it’s an attractive surface, but better in some places than others. Nevertheless, the whole effect is positive on a violin of a type that you’d normally see polished up like a bowling ball.

Experimenting with Ground Coats

bridges with ground testing

I started a series of tests this week, something I’ve always meant to do. I have a lot of scraps of wood with various things painted on them, but never have gone about it in an orderly fashion. Yesterday, I took a bunch of cheap bridges, scraped one side of each, and started putting a different ground coat on each one. Some dried right away, and I have some ideas about which of those I like. Others are going to take weeks or months to dry completely, but this time, when I look at them in a year, I’ll know what they are. (I have one little scrap of wood from about 20 years ago, stuck in a notebook, with nothing written on it, that if I knew what I’d done, that’s the varnish I’d be using.)

So far I’m testing Kusmi shellac, spray shellac, mastic, Ace spar varnish, oxidized turpentine, raw linseed oil, stand oil, propolis, gum arabic, and casein emulsion. As other ideas enter my mind, I’ll try them, too. Eventually I hope to have a sample of everything imaginable.

What started this whole thing was reading Jacques Maroger’s book, The Secret Formulas and Techniques of the Masters. It’s his analysis of the materials of the first Renaissance oil painters, and a couple of the things he mentions in the book made me wonder how they’d work as grounds. Maroger’s work is one contribution to how I originally got the idea for my uncooked mastic/linseed oil varnish (which is not the same as anything in his book), but I’ve never read his book before, because it’s hard to land at a price I could afford.