|
|
#1
03-09-2012, 01:53 PM
|
|||
|
|||
Cocobolo...any advantages to straight grain quarter sawn
I have a classical guitar from a domestic luthier.
The back and sides are cocobolo, totally straight grain and quarter sawn. Cosmetically it is completely unremarkable,,, This is not a problem for me,, im just wondering if there is any sound or resiliancey advantage to this, over the flowery, highly figured cocobolo.... by the way, it is age dried as opposed to kiln dried. No big issue for me, just curious Thanks, Rick
__________________
Classical guitars, flat top steel string A few banjos and mandolins Accrued over 59 years of playing Last edited by rgregg48; 03-09-2012 at 05:40 PM. 
|
|
#2
03-09-2012, 02:11 PM
|
|||
|
|||
|
The main advantage of straight grain, quartersawn cocobolo is that it is far more likely not to have cracks a few years from now. It also usually has greater cross-grain stiffness. This can translate into a tonal advantage if the builder knew how to work with it; the best wood can be worked thinner and thus lighter in weight while remaining sufficiently stiff and strong.
__________________
"Still a man hears what he wants to hear, and disregards the rest." --Paul Simon
|
|
#3
03-09-2012, 02:17 PM
|
|||
|
|||
|
Quartersawn wood is always more dimensionally stable that other cuts (it moves less with changes in humidity). That said, Cocobolo (along with Honduras Mahogany) has the least differential of any species.
But "more dimensional stability" does not always equal "less prone to splitting". Many species have less split resistance when quartered so it can be a trade off. Some species are stiffer when quartered. Not sure about Cocobolo. But that may be one reason some builders would prefer to use quartered, straight grain wood. Again, other builders might want something more flexible. I'm guessing you will get a variety of opinions on this. edit: i see you already have.
__________________
Chasson Guitars Web Site
|
|
#4
03-09-2012, 03:25 PM
|
|||
|
|||
|
Kent, I've seen the Forest Products lab figures on radial and tangential shrinkage. By their numbers, cocobolo and Brazilian rosewood are among the handful of most stable woods, and Brazilian is just as stable as East Indian. This doesn't jibe with my experience regarding splitting. But, as you point out, dimensional stability and resistance to splitting are not the same thing. I think what matters more is the ratio of tangential to radial shrinkage, and the elasticity of the wood. I also have observed that cocobolo, BRW, and other rosewoods are in most cases more prone to splitting on a guitar back when they are flatsawn. This is consistent with their radial and tangential shrinkage ratios.
__________________
"Still a man hears what he wants to hear, and disregards the rest." --Paul Simon Last edited by Howard Klepper; 03-09-2012 at 04:29 PM.
|
|
#5
03-09-2012, 03:39 PM
|
|||
|
|||
|
your guitar may have used strait grained cocobolo because thats what the builder had on hand at the time
__________________
IN GOD WE TRUST USN retired Dave Last edited by dchristo; 03-09-2012 at 05:52 PM.
|
|
#6
03-09-2012, 05:34 PM
|
|||
|
|||
|
Howard, obviously we've had this conversation before and I think we agree on many aspects of it. The only reason I continue to have it is because I and many other builders occasionally choose to buck tradition and build with something other than quartersawn wood and I stand behind my practices.
My only experience with splits is from repairs and talking to other builders. I just haven't had any problems with my own guitars. We do disagree about Brazilian though. I've seen an awful lot of splits in straight/quartered wood. I've also had a few conversations with someone who has likely built more Brazilian guitars than your and my total output combined. My understanding from him is that he has not seen a correlation. He prefers quartered wood but has seen plenty of it split and seen wild grain do just fine. Aside from obvious humidity abuse, I've come to believe splits are more related to building conditions, unseen flaws, and toughness (maybe what you refer to as elasticity) than anything else. I don't expect everyone to agree but that's my rationale.
__________________
Chasson Guitars Web Site
|
|
#7
03-09-2012, 07:44 PM
|
||||
|
||||
|
The two common cracks in Brazilian in my experience have two different causes. The Flatsawn crack is invariably what I call a heart check. It comes from drying tension and is associated with instability in variable humidity. It is the reason old school builders like myself prefer quarter sawn material. The other crack is much more common in quartered material, but it comes from abuse or rough handling. Just picking up a guitar with the thumb on one side and the fingers on the other can cause it, as can a small sharp blow or even stead pressure or going in/out of a case too quickly. I have made them myself several times and was in most cases alerted by the audible "ping", which I easily recognize now. For a guitar to realize the kind of performance I attempt to endow them with they must be built extremely lightly and that does make them fragile, especially in the harder rosewoods and their stand-ins.
|
