At 14:13 -0400 25/5/09, Ed Sutton wrote: >Is alcohol useful for softening all kinds of glue, or just hide glue? I'm not sure, Ed, because I've only ever used it for separating animal glue glue-lines. I think 'softening' is not the key word. Of course the glue will be softened with prolonged contact with alcohol and the water it usually contains in some small proportion, but what I think the alcohol does is almost instantaneously destroy the mechanical bond by finding its way rapidly right along the tiny fingers of glue that hold the wood together. Whether it has any effect also on the polar bond, I don't know. The application of some degree of pressure, with a jack, a knife, a lever etc. depending on the joint in question, tending to open up the joint, is to allow the alcohol to travel further into the glue-line once it has begun its work, so that it does not just sit in one place softening the glue and not getting anywhere. As the joint gradually opens up and more alcohol is fed in, you usually hear a crackling sound as the 'fingers' release their grip. I should emphasize that we are talking of ethyl alcohol. Methyl alcohol would probably do the same thing, but I doubt whether isopropyl alcohol would be effective, not that I've tried it. JD
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