Posted on

The Case for Using Natural Dyes

The Case for Using Natural Dyes

by Nicholas Von Robison

Originally published in Guild of American Luthiers Quarterly Volume 11, #1, 1983 and Big Red Book of American Lutherie, Volume One, 2000



Luthiers do not need to color their raw materials as much as other woodworkers. We use fine woods that can stand on their own merit without any help from the dye pot. But now and then we do find a need for dyes: for example, for rosettes, bindings, taking grey streaks from ebony, enhancing the color cast of wood, and tinting finishes.

In 1856 young William Henry Perkin was trying to synthesize quinine but instead wound up with a black tarry mess. This was mauveine, the first of the coal-tar derived dyes. By 1900 the aniline dyes (coal-tar derived) had virtually replaced all other dye materials. Up to this point, dyeing was done with naturally occurring materials and was more of an art than a science. With aniline dyes results were predictable, repeatable, stable, nonfading, and a heck of a lot simpler. There was bound to be a reaction, of course. The art of natural dyeing is returning to the amateur weavers and textile artists; I doubt if woodworkers will be far behind.

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

Questions: Spraying Lacquer in Garage

Questions: Spraying Lacquer in Garage

by Jeff Jewitt

Originally published in American Lutherie #101, 2010



MR in Portland, Oregon asks:

Anyone have suggestions for spraying lacquer in a small one-car garage? Do you really need an explosion-proof fan? I do have an unfinished bathroom in my basement, and it has a cheap exhaust fan.


Jeff Jewitt from Homestead Finishing Products in Cleveland, Ohio responds:

I definitely suggest a garage over a basement for spraying solvent lacquer. A basement is very hard to exhaust properly and most basements don’t have a large enough window for the fan necessary for flammable products. In addition, the residual odor from lacquer will be more noticeable in a basement than a garage.

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

Spraying Lacquer With Nitrogen

Spraying Lacquer With Nitrogen

by Harry Coleman

Originally published in Guild of American Luthiers Data Sheet #64, 1978 and Big Red Book of American Lutherie Volume One, 2000



There are several advantages of using compressed nitrogen for spraying over the more conventional air compressor. Air compressors, when pulling air right out of the atmosphere, also pull the moisture in the air right into the storage tank. Most of it can be filtered out, but not all. In addition, oil has a way of working its way from the piston assembly in the compressor into the air line and ending up on your work. Compressors are expensive and do break. You have to have a long enough air line to get the compressor out of the finishing room or a spark from the motor could blow you away. Long lines cause a drop in air pressure.

With nitrogen you are assured of 100% clean, dry “air.” Since there’s no motor involved, you can put the whole unit in the finishing room and use a shorter air line. The only disadvantage is that air is free, but nitrogen isn’t. You also have to take your tank out to get it filled. This is inconvenient, but the quality of the spray job makes it worth the trouble and expense, especially for a low-volume shop.

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

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

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.