<table cellspacing="0" cellpadding="0" border="0"><tr><td valign="top" style="font: inherit;"><div>My "thoughts" are that huge washers can be bought (2" or 3" O.D.) that are also quite thick (1/4") and that these will neither get "sucked" into the wood of the piano back (rendering the repair nearly useless) nor bend. Of course, the piano will have to be out from the wall a bit once the nuts are on the bolts and any excess bolt is sawed off, but I'd rather have that than a repair I need to worry about. (And the hex heads of the bolts in the piano's interior can be highly mirror-polished so that they are indistinguishable --to me, anyway-- from nickel plated.) It's been a couple of years since I bought such washers online, but I'll bet that Joe knows where best to get them.<br /><br />Thumpe</div></td></tr></table> <div id="_origMsg_"> <div style="font-family:arial, helvetica, sans-serif:font-size:10pt"> <br /> <div style="font-family:times new roman, new york, times, serif;font-size:12pt"> <font size="2" face="Tahoma"> <hr size="1"> <b> <span style="font-weight:bold;">From:</span> </b> paul bruesch <paul@bruesch.net>; <br> <b> <span style="font-weight:bold:">To:</span> </b> Pianotech List <pianotech@ptg.org>; <br> <b> <span style="font-weight:bold:">Subject:</span> </b> Re: [pianotech] Pinblock Separation <br> <b> <span style="font-weight:bold;">Sent:</span> </b> Sat, Jan 12, 2013 4:57:43 PM <br> </font> <br> <table cellspacing="0" cellpadding="0" border="0"> <tbody> <tr> <td valign="top" style="font:inherit;"><div dir="ltr">The one P/B separation repair I've done had to compensate for a couple of P/Rs done by yers trooly, so I absolutely had to let tension down. I still found it to be very hard to tighten my pipe clamps, and even bent one. I wound up letting it WAY down, at which point the clamps pulled it closed quite nicely. <div> <br></div><div style="">I used large washers in the back, but found the wood still crushed fairly considerably. It occurred to me at the time that I may want to glue on a 1/4" strip of maple or a hardwood plywood next time. Thoughts? </div> <div style=""><br></div><div style="">Paul Bruesch</div><div style="">Stillwater, MN</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sat, Jan 12, 2013 at 10:42 AM, Terry Farrell <span dir="ltr"><<a rel="nofollow" ymailto="mailto:mfarrel2@tampabay.rr.com" target="_blank" href="javascript:return">mfarrel2@tampabay.rr.com</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Theoretically, the tension does not have to be let down. However, it is possible that the piano has been getting pitch raises every time it's been tuned since the crack has been developing. IMHO, it is best to let the pitch down - unless perhaps the crack is small and the pitch is already a bit low. Just be careful!<br> <br> Also, if possible, sink all or most through bolts into a backpost for the most effective repair.<br> <br> Terry Farrell<br> <br> On Jan 11, 2013, at 8:26 AM, Jon Page wrote:<br> <br> > I've done this many times. The tension does not need to be let down. You do need many industrial strength clamps. I use hand screws and pipe clamps.<br> > Draw the crack closed with the clamps. Remove a screw and drill thru for a 5/16" bolt. A carriage bolt could be used but I have found the the soft face board on the back allows the bolt head to crush into the wood too much, so I use hex head bolts with washers. 3/8" bolts if more force is required.<br> > You could use T-nuts but they are pricey and chances are that your local hardware store does not supply enough.<br> ><br> > The reason to close the gap first is two fold. First, to prevent drilling debris from impacting into the gap, thus preventing its closure. Secondly, if the bolt hole were drilled prior to closing the gap then the holes on either side of the separation will no longer be in straight alignment once closed and the bolt itself will restrict closure.<br> ><br> > Many times glue is not needed for shallow separations. If glued, leave the clamps on overnight after all the bolts have been installed.<br> > Also, if the top is loose, bet that it is separated along the bottom as well. Check the bridge apron/body glue joints while you're at it. It's also good time to check the bridge notch at the treble break strut. Many time the bridge is touching the plate. Cut the bridge free with a saw blade drawn against the plate to recess the bridge. Might as well lube the casters while its on its back....<br> ><br> > -- Regards,<br> ><br> > Jon Page<br> <br> </blockquote></div><br></div> </td> </tr> </tbody> </table> </div> </div> </div>