Posted on May 6, 2021May 21, 2025 by Dale Phillips 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. ◆
Posted on April 29, 2021May 21, 2025 by Dale Phillips Rosin Varnishes Rosin Varnishes by Louis DeGrazia Originally published in Guild of American Luthiers Data Sheet #226, 1982 and Big Red Book of American Lutherie Volume One, 2000 Rosin varnishes are shunned by master violin makers because they are soft, “chippy,” and do not adhere well. Yet they are not so bad in these respects that they could not be used by an amateur or beginner on instruments with no pretension to outlast their maker. Pale rosin is a wonderful, natural, wood-derived resin that can be very easily made into a variety of beautiful and acoustically suitable varnishes both of the spirit and oil type. Its solubility in both alcohol and turpentine and its compatibility with oils and other resins make it a versatile ingredient that can help in combining normally incompatible substances to achieve special properties. Rosin varnishes have been around for centuries and in some respects they resemble those of the old Cremonese masters. Pale rosin in powdered form can be obtained from pharmaceutical companies which use it in preparation of salves and ointments. This is the purest grade and is recommended for varnish making. Rosin can be added to many varnishes to add body and to make them softer. Adding rosin to shellac makes a “woodcarver’s varnish” that can be prepared in just a few minutes, although it is best to let it stand overnight. This varnish brushes well, dries considerably slower than straight shellac, has good luster, and is much softer than shellac. To prepare, simply dissolve as much rosin as will go into solution in orange shellac and strain. 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 June 22, 2020May 22, 2025 by Dale Phillips Brazilian Guitar Makers Brazilian Guitarmakers by Roberto Gomes Originally published in American Lutherie #33, 1993 and Big Red Book of American Lutherie Volume Three, 2004 The guitar has been the main musical instrument in Brazil since it was brought by the Portuguese colonizers centuries ago. In those times, Baroque guitars were the most common string instruments. They had five courses of gut or wire strings. Since then it hasn’t changed much, as we can see in the “Brazilian viola” which is used for a kind of Brazilian country music called musica sertaneja (countryside music). The shape of the soundbox of this viola today resembles more a small classic guitar. Unfortunately there are very few records of those times, making it difficult to make a better study of those guitars and their makers. It’s known that most of the instruments were made in Portugal, Italy, and France. The first decade of this century brought three immigrant families from Italy: the Gianninis, the DiGiorgios, and the DelVecchios. These families were luthiers in their country of origin and later they founded the main Brazilian guitar factories which became the backbone of Brazilian-made guitars for nearly eighty years. They made mostly classic guitars and some violins, along with Brazilian violas. They also made mandolins, first with vaulted backs like lutes and later with flat backs, which are used to play choro music. 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 May 21, 2020May 20, 2025 by Dale Phillips Oil Varnish Techniques Oil Varnish Techniques by David Rolfe Originally published as Guild of American Luthiers Data Sheet #89, 1978 and in Big Red Book of American Lutherie Volume One, 2000 I decided to investigate the use of traditional oil varnishes as used by violin makers. At first sight, there seemed to be a lot of information around with enough detail to get on with the job. But as I delved deeper, I found enormous gaps in details of technique and lack of information on what is important and what is not. This is a detailed summary of what I have learned so far. My basic sources of information are the books and articles listed at the end. Materials Varnish. Traditional oil varnishes consist of a variety of resins, heated and dissolved in linseed oil, and turpentine. Coloring is added, and these agents can either be from the heartwood of certain trees (like dragon’s blood or gamboge) or organic mineral salts. Linseed oil is a slow-drying oil, and in conjunction with the resins, goes through the process of oxidation and polymerization (molecules of short length combine to become longer). Polymerization occurs mainly in the presence of ultraviolet light and continues for decades. Turpentine is used as a thinner or as a solvent to get the varnish on and then to evaporate in a relatively short time. The important characteristics of the varnish in liquid form are: 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 January 19, 2010September 10, 2025 by Dale Phillips Questions: Finish For Cocobolo Questions: Finish For Cocobolo by John McCarthy Originally published in American Lutherie #78, 2004 and Big Red Book of American Lutherie Volume Seven, 2015 Paul Dernbach of Naples, Florida asks: What is the best way to finish cocobolo? The varnish I tried on it isn’t dry after three weeks. It dried fine on my purpleheart sample. John McCarthy of Murfreesboro, Tennessee responds: The oils in cocobolo rarely dry well enough to use a gum-based varnish. I have had success with French polish (shellac) as a method for sealing prior to using any other finish. Shellac is unaffected by the oils in cocobolo. Build a thin layer of finish that doesn’t add much to the final coats. If you want to continue with the French polish, you will get good results and a very well-developed muscular arm at the same time. I tend to use shellac to seal then apply nitrocellulose lacquer over it. I like the results of French polish, but it is very time consuming and a bit difficult to match and repair if using other than as a base. I like the ease of a good nitrocellulose with a plasticizer which reduces the tendency of the finish to crack. I use an HVLP system to minimize overspray. I prefer Mohawk stringed instrument lacquer.