Wood grain orientation

[Thomas Yerkey]

Hi All,

I just re-sawed some beautiful black walnut for my first acoustic guitar. The tree was felled about 40 years ago. I have beautiful quarter sawn sides. My back plate has about 5 inches of quarter sawn grain, and then it changes through rift sawn into flat sawn. Given my design, I will have about an inch of flat sawn grain either down the center of the guitar back or along the edges. The book I am working from does not offer an opinion about how to orient such grain. What do you think? IS it better to put the flat sawn grain along the edges or down the center of the guitar back?

Thanks

[Peter Wilcox]

Just a guess on my part, but I'd think that structurally it wouldn't make much difference, since it's so heavily braced down the center. Myself, I'd orient it in whatever way it looked best.

[Barry Daniels]

I would put the most vertical grain down the center, where it will do the most good. The rift grain will be supported and attached to the sides so it really doesn't become an issue.

[Bryan Bear]

I'll echo both answers you got. I would put the quarter sawn portion in the middle because it is seems like the more important place for it but also because it probably would look best. Now if the flatsawn section somehow looks really cool when bookmatched and fits the outline nicely, I would consider changing my mind.

[Thomas Yerkey]

Thanks.

[Clay Schaeffer]

I agree with Barry. If the flatsawn grain is at the edges less of it will be used (the waist will remove some of it) and what is used will be better supported (by the curve of the sides and the braces). Most of the old guitars I've seen with some flatsawn grain follow this orientation. Ideally you should maximize the vertical grain.

[Randolph Rhett]

I have seen some high end guitars with completely flat sawn back (to best show figure). My sense is that since the back doesn't carry the load of the strings directly and is usually quite heavily braced (compared to a top), you shouldn't have to worry too much about the strength. Wood does expand and contract more in the flatsawn orientation, but with a mostly quarter sawn piece from a dried and stable billet, you are probably good to use wood in any orientation.