Hi all, As usual I'm coming in on the tail end of the bridge cap material discussion - just read all the contributions. I too, occasionally have used rock maple which has resulted in less than satisfactory cap material. Ron Nossaman mentioned his technique of laminating at Reno. We have been experimenting with the idea since then. Del mentioned the practice of inverting every second lamination to achieve a slight cross grain effect without wastage. We have been doing this also. Currently, we are making our laminations out of quarter cut rock maple (which is firstly resawn from wider slab cut boards). This is resawn again to 2.5 mm thicknesses then reduced to 1mm laminations with a drum sander. Our first laminated caps were ten laminations thick but we are now using only six. The 1mm thick laminations are glued together using West System epoxy. I am most impressed with the incredible strength of these caps. They seem to be cleaner sounding with less false beats and more powerfully toned than conventional solid maple caps. My thinking behind using only 1mm laminations is that often the boards are dried too fast, which causes minute checks to form during the drying process. These will often close during the final stages of drying, but they are still there. When such a deficient piece is converted into a solid bridge cap the results can be disastrous. However, if it is converted into 1mm thick laminations, it appears that the epoxy almost completely permeates the layers, gluing together any minute checks which may or may not be present. I believe this is the big benefit when using laminated caps, since the laminated variety seem to be very resistance to splitting, and as Ron N. mentioned, they also seem to have superior dimensional stability in response to humidity variations. Regards, Ron O. -- _______________________ OVERS PIANOS - SYDNEY Grand Piano Manufacturers Web: http://overspianos.com.au mailto:info@overspianos.com.au _______________________
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