On Thu, Mar 30, 2006, Rob Dorsey <[EMAIL PROTECTED]> said: > If the > soundboard is too roughly sanded (I don't sand a soundboard, I plane and > scrape only, even for final finishing) it can erode the softer material in > the lighter streaks more than the more dense lines, resulting in what I call > "cupping" of the surface.
I think of it more like a washboard, and in that perhaps I date myself. most any working of the surface (plane, scraper, sandpaper...) compresses both the dense and not-as-dense rings, when wetted during finishing the softer wood recovers from that compression; if the denser wood was taken past its youngs modulus it wont recover, also making a washboard. Over time the unfinished back of the top will allow moisture to infiltrate the top, this too will bring on watever washboard is lurking within the wood. -- Dana Emery To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
