Posted on August 1, 2022May 23, 2025 by Dale Phillips Questions: Tru-Oil Finishes Questions: Tru-Oil Finishes by Jeff Jewitt Originally published in American Lutherie #90, 2007 ■ Eric Nicholson of Northern Ireland asks: Woodworker magazine published an article on Stewart Adamson’s work regarding Tru-Oil finishes. His method involved a considerable amount of work with Micro-mesh during the process. I tried his method on my own guitars, both classical and steel string, with very satisfying results. Tru-Oil gives an attractive semigloss finish on all woods, but Adamson also goes on to say that for those that like a gloss finish, a gloss tung oil is now available only in the USA. Does anyone know of this gloss tung oil and where it is available in the States, or if it is now available in the UK? Jeff Jewett of Homestead Finishing in Cleveland Ohio responds: Tru-Oil is not pure tung oil. It’s a mixture of linseed oil, mineral spirits, and, according to the manufacturer, “modified oil.” It’s arguable that no tung oil is even used in this stuff. When finish chemists talk about “modified oil” as an ingredient they typically mean either chemical modification or heat modification. Chemically modifying a drying oil involves reacting it with chemicals and heat to form what are known as alkyds, which are used in varnish manufacture. Heat-treated oils basically jump start the drying/curing process. Pure heat-treated oils are used all the time in making finishes, but they rarely show up as “finishes.” The only pure heat-treated linseed oil I know of is Tried and True “Varnish Oil.” Pure heat-treated tung oil is sold in this country under the Sutherland Welles brand (www.sutherlandwelles.com). So I would be tempted to say that Tru-Oil is a mix of linseed oil and some sort of modified linseed or tung oil. Because it has a high oil content, it is not possible to produce a very glossy finish. High oil (also known as long oil) products tend to form microscopic wrinkles at the surface as they cure. There is one way to heat-modify pure tung oil so that it will form a glossy film. This involves careful and controlled heating of the oil to about 450°F. Very few people can cook tung oil properly nowadays, but you can buy it under the Sutherland Welles brand “Original Formula High Lustre.” I don’t know if they will ship overseas. It’s not an easy finish to do, and I’m not sure that it will match the gloss of a French polish, but at least you know it is real tung oil, along with solvent and some driers.
Posted on August 1, 2022May 21, 2025 by Dale Phillips The Accomplishment of Gary Karr The Accomplishment of Gary Karr by Frederick C. Lyman, Jr Originally published in Guild of American Luthiers Quarterly, Volume 11 ,#4, 1983 Gary Karr’s great achievement, which brought him world renown in the late 1960s, was that he performed on the double bass, in a completely fluent melodic manner. He had perfected a technique that employed the entire register of the bass with complete freedom, with perfect intonation, with consistency of tone-quality, with complete expressive control over dynamics, attack, and shading, and with a big, rich, full sound that would carry over an entire symphony orchestra as a solo voice. Gary was the first recognized artist to achieve this mastery of the bass, and, years later, when there are hundreds, perhaps thousands of very good bassists, he is still a uniquely great performer, a genuine unmitigated virtuoso who can dazzle the audiences like no one else. The immediate response to his work was wonder and delight, as it still is. 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 August 1, 2022May 19, 2025 by Dale Phillips Letter from London Letter from London by Theron R. McClure Originally published in Guild of American Luthiers Newsletter Vol. 3, #5 & 6, 1975 he early music buff finds much to enjoy in wintry England. During the first two weeks of December, 1975, Renaissance and Baroque music concerts were presented nightly at London’s Queen Elizabeth, Purcell, and Wigmore halls. The quality of performance specialists was held to the highest level; the dozen of early performance specialists was held to the highest level; the dozen of early performance specialists had a wonderful skill. In most performances nineteenth century playing mannerisms had been excised: e.g. vibrato was not heard from London violists. But the teaching of Arnold Dolmetsch and his followers were given little heed. In an all-Dowland concert at the Purcell room, only one ornament was heard from the instrumentalists the whole evening. Early music concerts draw full houses. There is a saying in London, that the old people go to the new music and the young people to the old. But a price has to be paid for this popularity: the larger the audience, the more the viols sound like the celli. Performers can’t keep from straining their instruments toward a commonplace tone. 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 August 1, 2022May 19, 2025 by Dale Phillips Bridge Positioning Bridge Positioning by Eric Henderson Originally published in Guild of American Luthiers Data Sheet #7, 1975 One procedure I use which your readers may find useful is that on my guitar top all the cross bracing and fan bracing is made up from the cuttings from the top blanks. For the cross bracing, I have to laminate two pieces together with the joint at right angles to the top. This procedure, I feel, guarantees that the woods are compatible. Another thing I do is when gluing the bridge I drill two small holes approximately 1/16" diam. in the slot for the ivory saddle, and when the bridge is precisely positioned, I drill through the top. The bridge can then be glued without being concerned about it moving because I temporarily inset two finishing nails in the two holes. The finishing nails are removed before the glue has completely set. The holes remaining are covered up by the ivory saddle. These are just two small items, but I would like to see the members who want to share small items like this write them up. ◆
Posted on August 1, 2022May 23, 2025 by Dale Phillips Questions: String Tension and Pure Tone Questions: String Tension and Pure Tone by R.M. Mottola Originally published in American Lutherie #98, 2009 See also, Questions: String Tension and Purity of Tone by Alan Carruth Pat Bowen from the Internet asks: A generally accepted fact is that the higher the string tension, the more pure the tone. This causes me grief, since I have to build instruments to support the heaviest strings. Even if I don’t recommend them, someone is going to use them. But is this thing about the high tension and pure tone really true or is it just a folk tale? The Questions Column editor responds: The short answer is yes, it is true, and the short explanation is inharmonicity. The higher the tension, the closer the partials are to true harmonic multiples of the fundamental frequency. On p. 115 of his book Engineering the Guitar — Theory and Practice, Richard Mark French states: “...increasing the radius [of the string] or elastic modulus [i.e., stiffness] makes the deviation from the ideal harmonic series worse, while increasing tension or length makes it better.” This is an interesting topic worthy of an article or at least a longer explanation than I’ve given here, which I hope someone will provide.
