Posted on June 13, 2024May 15, 2025 by Dale Phillips Sealing with Shellac and Varnishing Rosewood Sealing with Shellac and Varnishing Rosewood by Neil Hebert Originally published in Guild of American Luthiers Data Sheet #269, 1984 and Big Red Book of American Lutherie, Volume One, 2000 I have been using oil varnish on my instruments for years and have always found the finishing stages to be long and tedious. Still, I find the results of a good rubbed varnish job to be superior to lacquer; it gives the nicest “feel” to the guitar as well as showing the wood to the best advantage. One of the most ticklish problems in my experience is the seal coat of shellac, especially the first coat. The seal coat must be applied evenly in order to maintain consistent color on rosewood. The resins in the wood tend to wash out over the surface, which can result in irregular staining. I have tried three methods for applying this coat: 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 6, 2024May 23, 2025 by Dale Phillips Questions: French Polish VS Olive Oil Questions: French Polish VS Olive Oil by Gary Southwell and Koen Padding Originally published in American Lutherie #97, 2009 Stuart Mewburn from London, England asks: A recent request for an instrument finished with olive oil prompted me to do an experiment. I took two pieces of European spruce, the same size, oil finished one and French polished the other. I used virgin olive oil, applying one layer a day with a cloth and finished the next morning with Micro-mesh. Over fifteen days it built up a lustrous finish. Over the same time I applied thirty layers of French polish to the second piece of spruce. The oiled spruce (fifteen layers) weighed 2g more than the bare wood. The French polished spruce (thirty layers) weighed 1g more than the bare wood. If these figures are multiplied up to the size of the lower bout it means that the oiled top adds 33.2g to the weight of the working part of the top and the French polish adds 16.2g. When you consider that a bridge weighs about 19g–20g that’s a significant increase in weight for the strings to drive. The experiment begs a couple of questions. Has anyone done similar tests for other guitar finishes? To what extent does the mass of the finish affect the tone of the instrument? And as an aside, how well will a finish like olive oil hold up? 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 6, 2024May 28, 2025 by Dale Phillips Questions: Power Buffer For Finish Questions: Power Buffer For Finish by Charles Fox Originally published in American Lutherie #79, 2004 and Big Red Book of American Lutherie Volume Seven, 2015 See also, Questions: Post Buffing Finish Scratches by Brian Boedigheimer Mario from cyberspace asks: I use a power buffer to rub out my finish. It looks perfect to me at the time, but sometimes in other light I can see little tiny scratches that I’ve missed. Any advice? Charles Fox of Portland, Oregon responds: That reminds me of when I brought instruments to my first music trade show a few decades ago. Under the unforgiving glare of the convention center’s halogen lights I was appalled to see that the guitars, which I thought were perfectly finished, were in fact covered with tiny scratches that hadn’t been visible to me under either tungsten, fluorescent, or natural sun light. Now I do all of my finish work beneath halogen work lights. You can get an excellent ceiling shop light with double halogen lamps (part # 73995) from www.Rockler.com for $34.99. ◆
Posted on June 6, 2024May 22, 2025 by Dale Phillips Letter: Clarification of DVD review in AL#97 Letter: Clarification of DVD review in AL#97 by Ronald Louis Fernández Originally published in American Lutherie #99, 2009 Greetings, I thank Tom Harper for his review of my DVD, French Polishing for Guitarmakers 2.0 in AL#97. I wish to make a few clarifications. My family’s Spanish guitar business in the 1960s never involved Manuel Rodríguez. Rather, we had dealings with Miguel Rodríguez of Cordoba as well as Manuel de la Chica (Granada), Arcángel Fernández, Marcelino Barbero, Felix Manzanero, Hernández y Aguado, Juan Alvarez, and José Ramírez III. My article “Miguel Rodríguez: Some Notes on his Family Tree and Correcting the Historical Record” in AL#68 (Winter 2001) tells about the Miguel Rodríguez family and mentions my dealing with them. In a footnote of that article, I specifically mention the difference between Miguel Rodríguez of Cordoba and Manuel Rodríguez of Madrid. 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 6, 2024May 27, 2025 by Dale Phillips Questions: Post Buffing Finish Scratches Questions: Post Buffing Finish Scratches by Brian Boedigheimer Originally published in American Lutherie #86, 2006 See also, Questions: Power Buffer For Finish by Charles Fox Brian Boedigheimer of River Falls, WI responds to Mario’s question in AL#79 regarding what to do about tiny scratches in finish noticed after buffing: Charles Fox responded earlier to discuss lighting and I certainly agree lighting is key in so much of the work we do. Another thing to consider is the grading system of the abrasives one chooses to level the finish. There are three systems: CAMI, which is the U.S. standard grading system; FEPA, the European standard; and Micron grading. FEPA P800 is equivalent to CAMI 400. The P indicates the FEPA grading system, which is important because the grit particles are more uniform than in the CAMI system. Therefore there’s less chance of a stray large particle causing a scratch that we won’t see until buffing. So P800 gives you the cutting action of a 400 grit without the stray (larger) particles of the CAMI rating. Micron has the tightest tolerances for particle size, and if you have access to Micron-graded paper, that’s even better than FEPA. The equivalent Micron grade would be around 25 or 20. I recommend the FEPA grading system for abrading coatings until you’re into compounds; then you’re dealing with Micron. When sanding to level finish, the coarsest grit I would use is P400 grit, but typically I start with P600 or higher. I used to go through the process level-sanding with 320, 400, 600, and so on. The problem is, if you miss a 320-grit scratch working through the higher grits, you won’t know it until you buff out the guitar, and only in the right light will you see it. Now when I level-sand my finish before the final coats, I use P800 and spend just a little extra time with that one grit. It really doesn’t take me much longer, and I know those tiny scratches won’t suddenly appear. Then I spray the final two or three coats. Once that’s cured, I only have one grit of wet sanding to do before buffing. At that point I choose P1200. Don’t think that because each layer of nitrocellulose lacquer melts into the previous one, you won’t have stray 320 scratches show up. Even with that specific bond, a stray particle scratch from 320-grit CAMI-graded paper will show up when buffed out. I’ve experienced it. ◆
