In relating a field repair of some loose hammers I caused a discussion to open about the merits of Hide glue and Aliphatic Resin(Titebond) for hamer hanging and whether Titebond when it fully cured caused an unwanted twist due to it's inherant properties.Since the discussion raised questions in my mind as well I did some research and found some info at Bill Spurlock's site, actually a link to an article from woodezine(see below)on hide glue and an article from Frets Magazine(see below) on a test done between hide and Titebond. As I interpret the article from Frets the question of twist is answered by it. The reader must ignore the main body of the test, although the results are interesting, they are predictable given some thought. The point of the Frets article that I found interesting was that he took careful measurements of the joint, a lap joint, a much larger joint with more glue than a hammer and shank and it didn't change. The wood he was using was redwood, a much lighter more porous wood than the typical hammer molding and shank but he reported no change in measurement. He was doing this test questioning the use of Titebond for neck/fingerboard joints for guitars. An area a Luthier is going to be very careful to not have any twist in. I based my conclusions on that test and that is my reasoning for that conclusion. I must assume(something I rarely do)that the Luthier allowed the Titebond and the Hide glue to fully cure for his test, he is after all a craftsman of wood and would know his test results would be flawed had he not. Proof of this is that both glues held up in the initial portions of his test, if they weren't cured properly, they wouldn't have! I also took the opportunity this morning to call Franklin International(Titebond)and ask their Technical Assistance people if this was something they were aware of. The response was that the percentage of water to solids in Titebond is less than that in Hide glue, so if water based glue were the culprit it would/should be Hide glue. He did say he would check with some of the techs there and if he found anything else of interest, pass it along. I believe the question of hammer twist is more likely a case of possible lack of support for the hammer while the glue is curing or a rush to machine the shank ends off after gluing. When I hang hammers I allow them to fully cure for 24 hours before I do anything with them, the minimum cure time for both glues is 18 hours. If you try to rush that time, I believe you can be borrowing trouble. *FRETS.COM.htm* 6K View<http://mail.google.com/mail/?attid=0.1&disp=inline&view=att&th=11438277900e9fb8> Download<http://mail.google.com/mail/?attid=0.1&disp=safe&view=att&th=11438277900e9fb8> -- Michael Magness Magness Piano Service 608-786-4404 www.IFixPianos.com <http://www.ifixpianos.com/> email mike at ifixpianos.com -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070806/ad6ba6e8/attachment.html
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