Posted on

Drafting Instrument Plans

Drafting Instrument Plans

by Ted Davis

from his 1984 GAL Convention lecture

Originally published in American Lutherie #4, 1985 and Big Red Book of American Lutherie Volume One, 2000



I feel that for every 1% I put into the Guild, I get back about 120%. And I’m very high on the plan series. It’s an opportunity for repairmen and builders to preserve information about some instruments that would otherwise be lost. By making these plans available to more people, even if they don’t build them, they will see what they look like and what they are. Of course, you will also have the opportunity to build replicas of these fine old instruments. Many of them have historical value, and many of them have monetary value.

I’m sure there are a lot of “neophyte” luthiers in the audience today that would like to contribute to the Guild’s publications but just don’t feel they have the experience. Well, here’s something you can do. I’m sure you know someone that has a fine old instrument that’s a collector’s item, or perhaps you have one yourself, or perhaps the repairman will have one come into his shop. Take a few hours, take the dimensions of it, sketch it, and you can draw it at your leisure.

Drawing an instrument plan is not all that difficult, but it is time consuming. You’ll spend ten, twelve, maybe fifteen hours or more on your first one.

Become A Member to Continue Reading This Article

This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page.

If you are already a member, login for access or contact us to setup your account.
Posted on

Pre-bending Herringbone Purfling

Pre-bending Herringbone Purfling

by John Calkin

 

Herringbone purfling s a lot easier to work with if it is prebent before it is glued onto the guitar. This is best done after wetting it first. I always use a brush to spread glue on guitars. I keep a coffee cup of water handy at all times, along with an acid brush with the bristles properly trimmed back to the stiffness I like. I dip the brush, then hold it stationary as the strip of purfling is pulled across the cup underneath it. Soak the purfling well on both sides. This should take only seconds. Then the strip is pulled through a dry cloth. Soaking it for too long will encourage it to come apart as it is bent. Give the purfling a minute to absorb the water, then tape the butt end into the channel it will be glued in later. Wrap it carefully around the lower bout using a couple pieces of masking tape to hold it tight. More tape, as well as care, will be necessary to make it conform to the waist area. The wrap around the upper bout should be as easy as the lower bout. In the photo, you can see how much tape was used as well as the small fan used to dry the purfling before gluing it in place.

All photos by John Calkin

Herringbone will wrap around a moderate Venetian cutaway but do it gently and by stages. To be safe, the purfling can be wet and then sliced lengthwise on one of the glue joints using a single-edge razor blade.

On a tight Venetian cutaway, the purfling must be sliced. On this tight-waisted jumbo guitar, the purfling was sliced from the top end to below the waist area to help coax this half-herringbone purfling to conform to the shape of the guitar. Sliced purfling doesn't need to be prebent but you might wish to wet it as you reach that portion of the install. Slicing the purfling can go awry and destroy it. Buy extra.

Posted on

Blackboard Eraser Polisher

Blackboard Eraser Polisher

by Michael Dresdner

Originally published in Guild of American Luthiers Data Sheet #288, 1984 and Lutherie Woods and Steel String Guitars, 1998

 

I’ve been using a blackboard eraser to do final dressing on my frets. I take this nice soft eraser and a piece of 600 paper and go across the fretboard. It’s beautiful; it just follows the curve and gives you a nice even rounded top. This is for polishing, after you’ve shaped the frets with files.

Posted on

Twenty Ancient Dyestuffs and Eleven Mordants

Twenty Ancient Dyestuffs and Eleven Mordants

by Nicholas Von Robison

Originally published in Guild of American Luthiers Data Sheet #236, 1983 and Big Red Book of American Lutherie Volume One, 2000



Dyestuffs

1) Madder (Rubia tinctorum) is one of the most ancient dyes, and its color fastness ranks among the best. It is such an excellent source of red that its name (rubia) means red in several languages. In Holland during the 15th, 16th, and 17th centuries, it was the principal source of wealth. By 1792, encouraged by Charlemagne, France was the top grower. We are told that the French Revolution ruined the farmers. They were later revived by a decree of Louis Philippe, who made red caps and trousers mandatory for his army. In England imported madder was also used for army uniforms (redcoats). Before the “Madder Disaster,” England’s total imports came to one million pounds sterling. When alizarin, synthetic madder, was synthesized in 1869, a yearly world madder production of 70,000 tons declined to nothing. Historians speak of untilled and abandoned madder fields and of thousands of starving farmers (Schaefer, The Cultivation of Madder). Today madder can be hard to find; and sweet woodruff, one of the madder family that produces a less potent red dye, may be substituted. If you prepare the dye from roots, be sure not to use too much heat or boil it too long as the color may shift to a muddy brown.

2) Hemlock (Tsuga canadensis), also called eastern hemlock or spruce pine, is an important tannin dye. The bark, either fresh or dried, produces a wide range of colors from rose to slate gray. The nice thing about this plant is that it grows over a wide area of North America so it is easily procured with very little expense. I get mine from a landscape gardener who always saves me a bag of trimmings from one of his pruning jobs. A sharp knife will easily strip away the dark outer bark to reveal the red-purple streaks inside. It is not entirely colorfast.

Become A Member to Continue Reading This Article

This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page.

If you are already a member, login for access or contact us to setup your account.
Posted on

Finishing Lute Soundboards

Finishing Lute Soundboards

by Lawrence D. Brown

Originally published in Guild of American Luthiers Data Sheet #229, 1982 and Big Red Book of American Lutherie Volume One, 2000



There has been much discussion in early music journals recently about the materials used to finish lute soundboards. It would certainly be to our advantage if we knew exactly what was used on the soundboards of old instruments. Some people suggest that it is a moot point because no one is using exactly the same wood for soundboards that was used on old lutes. The old lute makers were almost certainly working under the same commercial pressures as any 20th-century workshop, and like us, used whatever high-quality timbers they could get ahold of. In addition, different luthiers probably used different materials and techniques to finish their soundboards.

It is well known that old lutes have very little or nothing at all on their soundboards. This would seem to be the most relevant point of all. Modern craftsmen have discovered that even one coat of varnish on a lute soundboard has a deleterious effect on the tone of the instrument.

Become A Member to Continue Reading This Article

This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page.

If you are already a member, login for access or contact us to setup your account.

Finishing Lute Soundboards

by Lawrence D. Brown

Originally published in Guild of American Luthiers Data Sheet #229, 1982 and Big Red Book of American Lutherie Volume One, 2000



There has been much discussion in early music journals recently about the materials used to finish lute soundboards. It would certainly be to our advantage if we knew exactly what was used on the soundboards of old instruments. Some people suggest that it is a moot point because no one is using exactly the same wood for soundboards that was used on old lutes. The old lute makers were almost certainly working under the same commercial pressures as any 20th-century workshop, and like us, used whatever high-quality timbers they could get ahold of. In addition, different luthiers probably used different materials and techniques to finish their soundboards.

It is well known that old lutes have very little or nothing at all on their soundboards. This would seem to be the most relevant point of all. Modern craftsmen have discovered that even one coat of varnish on a lute soundboard has a deleterious effect on the tone of the instrument.

The main concern of a historical instrument maker is to produce instruments that are acoustically, mechanically, and aesthetically similar to the instruments produced by early makers. This does not, however, preclude the use of any and all modern finishing materials. Modern lute makers must also respond to commercial forces and the demands of their customers, as long as this can be done within historical parameters. Bare wood accumulates sweat and dirt at a rate that is intolerable to musicians who are used to having a protective varnish on their instruments.

Because I build a great many lutes each year, I have been able to experiment with a variety of protective coatings on lute soundboards. Although my main concern has always been acoustical, I cannot ignore cosmetic considerations since lute making is rapidly becoming a very competitive market. For this reason, I have tried and rejected egg white sealers because they turn green — especially where the soundboard comes in contact with skin. Sodium silicate (water glass) also turns green and must be tinted with an orange dye in a lacquer overcoat. Oil finishes penetrate the wood too deeply and remain soft. They also collect dirt and discolor badly.

What is needed is a finishing material that will adhere to the surface but not penetrate it very deeply, a material that will dry to a hard, durable surface resistant to mild solvents; and a material that will go on in an extremely thin layer, so as not to have an adverse effect on the tone of the instrument.

This is the most successful method that I have found so far. It requires the use of a compressor and a spray gun, lacquer sanding sealer, lacquer, and lacquer thinner. I use a touchup gun. It is smaller than a standard gun and holds about a pint of liquid. It also has a smaller spray pattern than a larger gun, which seems about right for spraying a lute-size instrument.

Mix 1 part lacquer sanding sealer with 1 part solvent. This makes an extremely thin solution that dries instantly when sprayed on the soundboard, preventing it from soaking into the wood. (If the spray gun is held too far from the soundboard, the solution will dry in the air and deposit a dusty film on the instrument.) Sand lightly with very fine paper or steel wool. This is followed by two coats of lacquer, also mixed 1/1 with solvent. This makes an extremely thin coating that seems to have no effect on the tone of the instrument, but provides a hard and reasonably durable surface. The lacquer sanding sealer not only seals the wood but makes an excellent bonding coat between the wood and the lacquer coat. The surface may be lightly smoothed with steel wool. The reduces the gloss to a uniformly dull finish.

I have tested the acoustical effects of this finishing technique by playing the instrument in the white and after being finished. I have also compared the tone of finished instruments to identical instruments that have not been finished.

It has been noted that old lute soundboards seem to be somewhat dark in color. This was probably due to the effect of ultraviolet light on the wood. Mask one-half of a newly cut and sanded soundboard with heavy paper and leave it around the shop for a month. It does not have to be in direct sunlight. Notice how dark the exposed side of the wood becomes after such a short time. I have noticed that different types of spruce seem to darken more quickly than others. I really doubt that early lute makers artificially darkened the soundboards of old lutes, since this would mean coating the wood with an additional substance when the tendency seemed to be to put as little as possible on the soundboard.

I regularly get a variety of Middle Eastern stringed instruments, including ouds, in my shop for repair. These instruments normally have bare, untreated soundboards. The older ones (20–60 years old) have turned quite dark and closely resemble the lute soundboards in old paintings. In most instances they are not just UV-light darkened but uniformly dirty. In any case, why should we be trying to build lutes that look 20–60 years old when they are brand new? I, for one, am content to wait a few years.