Posted on August 1, 2022March 5, 2024 by Dale Phillips Potassium Dichromate, Oxalic Acid, and Carnauba Wax Potassium Dichromate, Oxalic Acid, and Carnauba Wax by Jeffrey R. Elliott Originally published in Guild of American Luthiers Data Sheet #52, and #55, 1977 and Big Red Book of American Lutherie, Volume One, 2000 Potassium dichromate. European luthiers commonly use potassium dichromate to give that nice, brown “aged” look to lighter, newer woods. It can be used by itself or mixed with aniline dyes for additional color tints. Primarily it has been used to darken the interiors of violin-family instruments, although I know of many who have used it on the exterior to darken spruce and maple. I have used it both inside and out to create a “naturally aged” looking wood on guitars. Potassium dichromate is a chemical activated by light from the sun, sunlamp, or infrared lamp, but direct, natural, full-spectrum sunlight is best. Beware: Indirect light will not activate it, and the solution will tend to color the wood a murky green. The solution is rather weak — two tablespoons to one gallon of water. It can be applied by brushing or by wiping it on with a cloth (wear gloves). Although I have never tried it, I imagine a spray method would work as well. Whichever method is used, a light, even coat is recommended. 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, 2022March 5, 2024 by Dale Phillips Curved Panel Templates Curved Panel Templates by Reagan Cole Originally published in Guild of American Luthiers Data Sheet #80, 1978 Many instrument makers prefer to build guitars, mandolins and the like with pronounced curvature to the back panel(s). The most common method of fabricating a “vaulted” back is to work from a solid plug mold which must be carved and shaped to very exacting standards to produce acceptable results. The plug mold is in fact the best answer when one is building a number of identical instruments. The drafting technique I shall describe is a workable alternative for “one-off” projects or as an aid in visualizing three dimensional forms. Begin by making a full scale orthographic drawing of the intended form. This will show the back and side views, but it is not directly useful in determining the dimensions of thin wood (or other material) to be used in the construction. 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, 2022March 5, 2024 by Dale Phillips Intro to P.E.G. Intro to P.E.G. by H.E. Huttig Originally published in Guild of American Luthiers Data Sheet #35, 1976 This is an abstract of an article written by Mr. H.L. Mitchell, retired Chief of the former Division of Wood Quality Research, Forest Products Laboratory, U.S. Dept. of Agriculture. Not all material contained may be useful to luthiers. I leave it to the individuals to choose such things as they may wish to try and to apply to instrument building. Wood is an exceedingly complex and variable material. You will know that wood shrinks and swells with changes in atmospheric moisture. This plus problems of checking, splitting, warp, and broken glue joints are all too familiar to you. Treatment with PEG (Polyethylene glycol–1000) greatly improves the dimensional stability of wood and eliminates many of the problems. 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.
