Make a guitar with William
William Cumpiano/Rich Janes
Compression-molded, 100% carbon-fiber laminated guitar soundboard
Cumpiano guitar illustrated on the right is entirely made with traditional materials
-- all except for its black sound board, which is made from William's patented
compression- molded graphite carbon-fiber-laminate material.
From time immemorial, softwoods such as pine, spruce, and cedar have been selected by instrument-makers for the sound boards of their stringed instruments. The tradition continues to this day. Indeed, modern makers select these traditional materials for the same reasons as did their forebears: they are efficient, (i.e. very stiff relative to their weight); they can bear considerable loads (such as that imposed by string tension) even after they are sawn into thin sheets. Optimally, sound boards are thin in order to minimize mass, mass which can dampen the vibrations and reduce the sustaining quality of the sound.
Graphite/ Macassar Ebony Cutaway Classic by William Cumpiano
William relaxes with his Koa/graphite steel-string
|But thin sheets of softwoods crack easily when
exposed to ordinary climatic changes. They also "creep." Creep is a technical
term that describes the plastic deformation of a material after it has been under stress
for a long time. After years of use, many lightly-constructed guitar tops display
rippling, sinking, and bulging -- deformations that remain "set" even after the
string tension is released.
A logical alternative to spruce for sound boards are modern fiber-composite materials. They, too, are strong and light. They are also more uniform, an advantage that simplifies production processes. A shiny, jet-black carbon sound board was developed over a period of two and a half years by Rich Janes, a product-development engineer with over fifteen years of experience in the field of fiber composites; and guitarmaker William Cumpiano. Together, they developed a multi-laminate fiber-composite material that closely mimics the an-isotropic (non-uniform) stiffness characteristics of spruce.
The material is seen by its developers as "a modern alternative to the traditional softwood sound boards" which can be used on all kinds of plucked stringed instruments. Cumpiano said, "we designed the material as an analog to Spruce wood--which, by the way, is also made up of carbon-based fiber. The trick was to design the lay-up of the sheets to mimic the peculiarities of the natural material, so that its sound would be similar.
The material is composed of many laminations of resin-impregnated carbon fiber "skins" which are laid up in a special way. The lay-up is then heat-pressed to a 1/16 to 1/32-inch thickness. The process yields an enormously strong, stable and light material that will never creep or crack. The material also displays superior acoustic characteristics: when held up and rapped with the knuckles, the material rings like a bell! The material's outer face displays a beautiful, woven layer of carbon fiber a under polished lacquer" Indeed, a small number of other instrument manufacturers have developed their own composite soundboards, notably the Ovation and Decker/ Windsong guitar companies. Their own patented processes, however, are significantly different from the Janes and Cumpiano patent, and result in sound boards that are not as acoustically efficient or as attractive.
Although industry has been slow on the uptake, William is currently producing extraordinary sounding steel-string and classic guitars, in small quantities, using his patented "Fibracustic" soundboards.
Find out more about how to obtain and evaluate these instruments here.