This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment ----- Original Message -----=20 From: Brian Trout=20 To: pianotech@ptg.org=20 Sent: Thursday, August 05, 1999 7:14 PM Subject: Old Knabe Pinblocks Hi All, =20 I have a job in the shop waiting for me right now. It's a Knabe = grand, 7'4" I think, late 1800's, with a full plate. The pinblock is = sloped, and also curves from bass to treble. If you've seen one, you = know what I'm talking about. =20 The pinblock is to be replaced. I guess what I need is some advice as = to how to attack the beast. I want to do it right. The main problem I = seem to run into is that to remove the pinblock completely, it's almost = impossible without tearing off the top front parts of the case. (The = pinblocks I've seen like this one were screwed in before the case = assembly was finished, and not intended to be removed.) =20 Have any of you come up with a better way to do a pinblock replacement = on these? =20 = -------------------------------------------------------------------------= ---- Brian, et. al., This has been an interesting series of posts to follow. Having done a = couple of these in the past, perhaps I might be allowed to comment.... First, these things look far more intimidating than they actually are. = What you are faced with is simply a task that will require somewhat = more, and more demanding, woodworking that is usually called for. = Believe me, though, if I can pull one of these things off, most anyone = else out there can as well. I have not tried filling the holes with epoxy and re-drilling. It = might work, though. Epoxy, by itself, does exhibit a fair amount of = creep under load, but in this case it is just being used to reinforce = the wood fiber surrounding the pin. Basically what you would end up = with a fiber-reinforced plastic pinblock. Which may or may not be a = good thing. I'm not really qualified to evaluate the idea. But, far be = it from me to stand in the way of progress.=20 I have, however, encountered pinblocks that have been plugged and I = have encountered pianos in which portions of the pinblocks have been = routed out and inserts installed. Some have held up well, others have = abjectly failed within just a couple of years. I have encountered = inserts that have pulled loose and pinblocks in which the plugs weakened = the structure -- no, the glue holding the plug in does not make the = structure as strong as it was before you drilled out all that wood -- = sufficiently that the blocks had actually broken. So, for me, both of = those options would be out. My choices would come down to an epoxy repair of some sort or, my = preference, replacement of the original block. Taking the rim apart at = the bass end -- you shouldn't have to get into the treble end at all -- = just isn't that difficult. Neither is putting it all back together and = doing a bit of re-veneering. Cutting the original block loose from the = stretcher is also not terribly difficult. The only real challenge is = shaping the actual pinblock panel and fitting it to the plate. This can = be done fairly quickly using a variety of power and hand tools. And, = yes, we do cheat and do the final bedding to the plate using an = epoxy/wood flour matrix. I am currently updating my old class outline on replacing these = blocks. I'll be happy to send you a copy -- once it is completed -- if = you're interested. Regards, Del ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/3b/59/af/e5/attachment.htm ---------------------- multipart/alternative attachment--
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