JMguitars
New member
Interesting read from Jack Brigg, posted on his forum.
http://www.briggsguitars.com/forum/viewtopic.php?t=47
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With the interest in hand made guitars from small independent luthiers, the term "Eastern maple" is tossed around oh so often. And just as often, nobody seems to have questioned the accuracy of the term.
Let's examine:
Eastern maple
There is no specie of maple known in the arboreal world as "Eastern maple" per se. Several species grow in eastern locations that could be called "Eastern" as maples go. So what do most guitarists and luthiers mean when they're referring to Eastern Maple? Most often the maple that's referenced is the specie acer rubrum, or red maple. But there are other maples in the eastern United States: silver maple (a. saccharinum), sugar or rock maple (a. saccharum), box elder (a. negundo), black maple (a. nigrum), striped maple (a. pennsylvanicum) and mountain maple (a. spicatum). Having worked with at least 4 of these species, I can say that they are markedly different in respect to density and specific gravity: the two most influential specifications influencing tone transfer.
Hide Glue
A lot of debate continues to on the subject of glues used in instrument production. The old-school vintage junkies swear that hide glue - made by the rendering of the hides of cows or horses - is the best way to attach wooden parts together in building guitars, whether electric or acoustic in nature. Many electric guitar builders will nay-say and tell you that modern bottled glues are far superior to the centuries old hide glues. Anyone who says this clearly has an agenda for doing so. Simple tests are all that's needed to proclaim hide glue's superiority. Again, an agenda for saying otherwise would possibly include the fact that hide glue has to be handled with a certain amount of care and attention. It must be dissolved in water and slowly heated to 140-145ºF and used quickly before it cools as it starts to gel at about 100ºF, at which point the glue is not to be used for fear of a failed joint in the future. This is reason enough for higher-volume builders to shy away as it just isn't practical to use in a production environment. But to the independent luthier, it's not a big deal.
The difference in the completed joint is where the proof of the pudding lies. Hide glue dries to a totally crystalline state - one which does not hamper in any way the transmission of sound waves. Joints made with hide glue also require less actual glue to hold the joint, enabling a much tighter woodworking joint be made (another sound wave transmission enabler). Bottled glues used by luthiers are almost all PVA or polyvinyl acetate, which is a rubbery synthetic polymer produced by the polymerization of vinyl acetate monomer. In other words, it's vinyl based. Vinyl is a well known sound insulator. While PVA glues can seemingly dry hard, they will never approach the crystalline nature of cured hide glue. Another aspect of hide glue worth noting is that hide glue joints from several hundred years ago still are intact to this day! It has survived the test of time, to be sure.
Old Wood
Another area of much ballyhooing. What is "Old-growth" wood? Most definitions state that old-growth woods are milled from trees that were growing on these lands when the first European settlers arrived on our shores. Or maybe it can refer to tonewoods that were milled a long time ago? More important is the distinction of whether the woods were air-dried or kiln-dried. These terms refer to the initial drying of the timbers from green (approx. 30% moisture content) to usable (typically 6-8% equilibrium moisture content. There is a dynamic difference between wood that is initially air-dried and wood that is kiln-dried. Kilning woods for initial removal of free and bound water leaves cell walls somewhat to very much collapsed. Natural air-drying of same leaves the cell walls intact, which in the finished product act as tiny little acoustic chambers. Air-dried woods are noticeably more lively sounding and resonant, making for a more resonant and lively instrument. But it takes much more time for tonewoods to be air-dried and fully cured. Air-dried woods still need final curing to be performed under slightly higher temperature levels (AKA kilning) to attain the equilibrium moisture content required to build instrument with. This does nothing to reverse the benefit of initial air-drying.
Nitrocellulose Lacquer
Nitrocellulose lacquers appeared in the 1920's and quickly replaced varnish finishes on furniture and stringed instruments because of its faster drying time and ease of application. Lacquer production also ushered in the development of spray guns, which was and still remains the primary means of applying lacquer to a substrate. Other finishes popular with instrument builders include polyester and polyurethane coatings. Of the two, polyester finishes always are catalyzed finishes or having a chemical hardener added to the main coating ingredient. Polyurethanes may be either solvent based or catalyzed. What an instrument would like to see on it is as thin a coating as possible, so as not to hamper the resonation of the tonewoods. Any of the above finishes may be applied very thinly. Just as important to some is the feel of the finish coating. This is where nitrocellulose finishes can vary some, depending upon the manufacture of the lacquer material. Almost all have some amount of plasticiser, designed to keep the finished and cured film from cracking and crazing due to the expansion of wood over time. This is one thing that will occur over the lifetime of the instrument, as wood always moves. The key is to find a nitrocellulose lacquer with a minimal amount of plasticiser to prevent the cured finish from taking on a "plasticky" feel, which can be heightened by excesses of temperature and humidity.
http://www.briggsguitars.com/forum/viewtopic.php?t=47
-------------------
With the interest in hand made guitars from small independent luthiers, the term "Eastern maple" is tossed around oh so often. And just as often, nobody seems to have questioned the accuracy of the term.
Let's examine:
Eastern maple
There is no specie of maple known in the arboreal world as "Eastern maple" per se. Several species grow in eastern locations that could be called "Eastern" as maples go. So what do most guitarists and luthiers mean when they're referring to Eastern Maple? Most often the maple that's referenced is the specie acer rubrum, or red maple. But there are other maples in the eastern United States: silver maple (a. saccharinum), sugar or rock maple (a. saccharum), box elder (a. negundo), black maple (a. nigrum), striped maple (a. pennsylvanicum) and mountain maple (a. spicatum). Having worked with at least 4 of these species, I can say that they are markedly different in respect to density and specific gravity: the two most influential specifications influencing tone transfer.
Hide Glue
A lot of debate continues to on the subject of glues used in instrument production. The old-school vintage junkies swear that hide glue - made by the rendering of the hides of cows or horses - is the best way to attach wooden parts together in building guitars, whether electric or acoustic in nature. Many electric guitar builders will nay-say and tell you that modern bottled glues are far superior to the centuries old hide glues. Anyone who says this clearly has an agenda for doing so. Simple tests are all that's needed to proclaim hide glue's superiority. Again, an agenda for saying otherwise would possibly include the fact that hide glue has to be handled with a certain amount of care and attention. It must be dissolved in water and slowly heated to 140-145ºF and used quickly before it cools as it starts to gel at about 100ºF, at which point the glue is not to be used for fear of a failed joint in the future. This is reason enough for higher-volume builders to shy away as it just isn't practical to use in a production environment. But to the independent luthier, it's not a big deal.
The difference in the completed joint is where the proof of the pudding lies. Hide glue dries to a totally crystalline state - one which does not hamper in any way the transmission of sound waves. Joints made with hide glue also require less actual glue to hold the joint, enabling a much tighter woodworking joint be made (another sound wave transmission enabler). Bottled glues used by luthiers are almost all PVA or polyvinyl acetate, which is a rubbery synthetic polymer produced by the polymerization of vinyl acetate monomer. In other words, it's vinyl based. Vinyl is a well known sound insulator. While PVA glues can seemingly dry hard, they will never approach the crystalline nature of cured hide glue. Another aspect of hide glue worth noting is that hide glue joints from several hundred years ago still are intact to this day! It has survived the test of time, to be sure.
Old Wood
Another area of much ballyhooing. What is "Old-growth" wood? Most definitions state that old-growth woods are milled from trees that were growing on these lands when the first European settlers arrived on our shores. Or maybe it can refer to tonewoods that were milled a long time ago? More important is the distinction of whether the woods were air-dried or kiln-dried. These terms refer to the initial drying of the timbers from green (approx. 30% moisture content) to usable (typically 6-8% equilibrium moisture content. There is a dynamic difference between wood that is initially air-dried and wood that is kiln-dried. Kilning woods for initial removal of free and bound water leaves cell walls somewhat to very much collapsed. Natural air-drying of same leaves the cell walls intact, which in the finished product act as tiny little acoustic chambers. Air-dried woods are noticeably more lively sounding and resonant, making for a more resonant and lively instrument. But it takes much more time for tonewoods to be air-dried and fully cured. Air-dried woods still need final curing to be performed under slightly higher temperature levels (AKA kilning) to attain the equilibrium moisture content required to build instrument with. This does nothing to reverse the benefit of initial air-drying.
Nitrocellulose Lacquer
Nitrocellulose lacquers appeared in the 1920's and quickly replaced varnish finishes on furniture and stringed instruments because of its faster drying time and ease of application. Lacquer production also ushered in the development of spray guns, which was and still remains the primary means of applying lacquer to a substrate. Other finishes popular with instrument builders include polyester and polyurethane coatings. Of the two, polyester finishes always are catalyzed finishes or having a chemical hardener added to the main coating ingredient. Polyurethanes may be either solvent based or catalyzed. What an instrument would like to see on it is as thin a coating as possible, so as not to hamper the resonation of the tonewoods. Any of the above finishes may be applied very thinly. Just as important to some is the feel of the finish coating. This is where nitrocellulose finishes can vary some, depending upon the manufacture of the lacquer material. Almost all have some amount of plasticiser, designed to keep the finished and cured film from cracking and crazing due to the expansion of wood over time. This is one thing that will occur over the lifetime of the instrument, as wood always moves. The key is to find a nitrocellulose lacquer with a minimal amount of plasticiser to prevent the cured finish from taking on a "plasticky" feel, which can be heightened by excesses of temperature and humidity.
