At 11:02 PM 9/26/2002 -0400, you wrote: >A lot of the tops I have reglued come loose in a relatively short time. I >attribute it to the difference in expansion and contraction rate from >humidity changes between the ivory or plastic and the wood, and the low >shear strength of the glue. I've never had trouble with ivories coming off again, using CA glue. What was the relative humidity when they were glued on? It may be that the glue never set well to begin with (air too dry?) I've sometimes used a damp rag to clean off the dark dirt, so that the remnants of the old wafer (containing hide glue) are just barely damp to the touch. Then I put CA (Quiktite, from Loctite, as usual) on the back of the ivory, spread it quickly to form a sheet all the way to the edges using a small screwdriver, and carefully but quickly put it in place. Usually a little squeeze-out gets on my fingers, and if I'm not careful, some gets on the top of the ivory as well. So I carry some nail polish remover, to get it back off again. A really good flush fit before you put on the glue helps as well. CA is a pretty lousy gap-filler. Donnie Byrd glued a whole set of plastic keytops onto an upright in Cuba, using Titebond and CA (together). When she checked the next year, not one had come loose. My suspicion is that poor adherence is more likely in low humidity rather than high, but I'll keep my mind open to contrary data. Susan
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