I am tempted to believe that the block was not pulled together before the bolts were added. I have never seen one I repaired come apart again. I use carriage bolts, and intentionally imbed them in the wood, then they don't turn. I have just used regular glue. The bolts would not 'stretch', they would break, if the tension were too much. Especially 1/2". The person was probably just using the bolts, to pull it together, or just make sure it didn't get worse. Clamps should definitely be used to close the gap, before the holes are drilled. Just as a matter of interest, how far down in pitch was the piano? John Ross Windsor, Nova Scotia, Canada jrpiano at win.eastlink.ca ----- Original Message ----- From: "Euphonious Thumpe" <lclgcnp at yahoo.com> To: "Pianotech List" <pianotech at ptg.org> Sent: Saturday, March 29, 2008 3:08 PM Subject: Epoxy for separated pinblock, or Titebond (I,II or III) ??? > Once again, I've seen a case of a "repaired" pinblock > ( carriage bolts through back, with washers and nuts ) > that has failed. > This time, although the back is rock maple, the > string tension STILL sucked the nuts and washers into > the wood so far, that there's a 1/2" gap between the > pinblock and the back frame!!! > ( Stretching the bolts, too??????? ) > So, I'm about to glue it all together. ( With #8 > bolts all the way through, and a thick steel plate all > along the back that CAN'T get sucked into the wood! ) > I'm sure it doesn't matter, with the > compreghensive arrangement I'm using, which will > "sandwich" eveything together. > But I'm still wondering: what's better in an old > glue joint ??????? > Epoxy: which is very strong but will not ( perhaps) > bind with the old glue? > OR > One of the Titebond glues, which WILL. ( Because > they're both water soluble. ) > Thumpe > > P.S. "Test Tip": Run a sample strip of all your > favorite glues on the lid of one of those plastic > salad trays, mark them, then peel them off and play > with them after a week or so. You can see whixch are > tough, brittle, flexible, waterproof, etc. > --- Michael Kurta <mkurta at roadrunner.com> wrote: > >> > > Euphonious Thumpe > > > > ____________________________________________________________________________________ > Like movies? Here's a limited-time offer: Blockbuster Total Access for one > month at no cost. > http://tc.deals.yahoo.com/tc/blockbuster/text4.com >
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