At 08:23 04/10/01 -0700, Delwin D Fandrich wrote: >Are you using the birch material Delignit (?) Delignit is bEEch, rock maple's European substitute. > makes just for bending grand >rims? Or is this the off-the-shelf variety of birch ply? Off the shelf 3-ply (3mm total) x 8' x 4' sheets. If I saw out strips across the grain these are, of course, very flexible and will bend without difficulty round any continuous rim curve. Since my outer rim will be in four parts, lapped and dowelled, the building of the rim will require nothing but a simple buck or former, which can be reproductive, spawning other bucks. Since Erards are the topic of the day, my master buck was made at Erard's in Paris about 1850, but I ought to admit that it went about pretending to be a piano for many years! I don't know what you others use for glue but I'm using a well tried urea formaldehyde glue (Aerolite) which involves coating one face with the paste and the other with acid (formic? very pungent anyway) which acts as a catalyst. If I can devise, inherit or find a cheap system for radio-frequency heating, I will use that to reduce dramatically the clamping time required. I believe similar glues and rf heating are commonly used in the plywood making industry, or always used to be. I was with an organ builder the other day and he uses a casein glue, never having heard of Aerolite. I dislike casein glues and their pot life is not good. Aerolite's pot life is as good as limitless, which makes it very convenient to use for time-consuming jobs and any left over will still be usable days hence. The adhesive sets very hard and fills gaps pretty well. JD
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