The Hazelton Grand is repaired and up to pitch and sounding great. I had wanted to do locknstitch, but getting the details together was proving weighty. So I listened to what Willis Snyder had said, "Bolt a plate on the underside of the frame", and called an engineering/welder friend to talk me through. He recommended a 1/4 inch steel plate, and drew a pattern on the underside of the frame, marking general locations for 3/8 inch bolts. I created a cardboard pattern, leaving openings for the access holes, and a local metal shop made it for me. I drilled and tapped into the frame fifteen holes, drilled out the steel to match. Then, cleaning both surfaces with a belt sander and denatured alchohol, applied a layer of PC-7 on both surfaces. Next I bolted the sandwich together. The engineer calculated that the 12 inches of 1/4 steel I had added could carry upwards of 100,000 lbs. of stress by itself, seeing that a 1 inch rod of steel will hold 40,000. I set the bearing with a little help from epoxy putty. A few days later I drew up tension in 1/36 th increments, (very carefully). A-440 and holding perfectly. Full regulation and voicing followed. The client was here today to play it, and could find no serious complaint. The steel plate method was very cost effective, $20.00 for the plate, 3' threaded bolt and 15 nuts, PC-7, sandpaper,etc. plus time. I owe a couple of helpful experts for their time - Even if the PC-7 failed, the plate and bolts are enough to hold this. And the repair is all underneath, with only a little roughness on the top where the bolts came flush with the surface. I smoothed that out with a little super glue. A little masking, and re-guilding, and it looks very presentable. I do have the repair on digital if anyone wants to see it. It cannot go through the list, however so send requests to rchayden1@juno.com. I will let the world know if this thing ever comes apart. Roger C. Hayden, RPT On Fri, 31 Mar 2000 13:15:27 -0500 Roger C Hayden <rchayden2@juno.com> writes: > To those who are curious: > > I'm persuing the locknstitch method. I've talked to them in Calif. > and > they want pictures. The method for me is to cut out (saw out) the > crack > and heat affected area, make a steel 'plug' to fit back in, and > metal > stitch it back together. Stronger than original. They are using > this > method on pianos already. > > Gary, my contact, has already taught Pianotechs out there on the > left > coast, and was invited to teach it at the Nat. convention in > Arlington > but couldn't schedule it this year. > > We're on to something!! > > Thanks for the tip, Greg > > Roger Hayden, RPT > > On Tue, 21 Mar 2000 09:12:11 -0800 Greg Granoff <gjg2@humboldt.edu> > writes: > > > > > > Roger C Hayden wrote: > > > > > OK, Guys, I need help > > > > > > Hazleton Bros. 5'10" Grand. Neatly rebuilt, (by me). Too > little > > > downbearing in the treble, so I lowered it a bit. (I've Done > such > > things > > > before.) Brought up the tension nice and evenly, installed > > dampers, > > > sounding good at A-440, ready for fine tuning. > > > > > > During the Fine Tuning: THWUNK !! I couldn't see anything, so > I > > played > > > a chromatic scale. It climbed nicely until I passed the last > > strut, and > > > dropped a fourth. Then I could see the crack, travelling toward > > > the > > > Northeast, but holding near the edge of a circular sound hole. > I > > QUICKLY > > > dropped tension on that section, and then dropped the rest of > the > > piano. > > > > > > Fortunately this pinblock is only attached to the frame, and not > > > to the > > > case, so I loosed everything, pulled out the frame with the > block > > and > > > strings intact, and called a welder who assured me he could > handle > > this. > > > > > > Re-painted, reinstalled, strings back in place, tension up to > > A-440 and > > > holding. Last Friday before bed I played a chromatic scale > > again, and > > > it wasn't chromatic. . . . . . So I dropped the tension on the > > last > > > section and went to bed. > > > > > > There's more to welding cast iron then I knew. My welder did > not > > heat > > > the plate, nor cool it slowly, as I hear is necessary. And I've > > > heard > > > from a far more skilled fellow, that this kind of welding is > very > > much an > > > art. > > > > > > Question: What if I had a steel plate created, and with PC-7 > > between it > > > and the underside of the frame to give it strong frictional > > contact, > > > drilled, tapped and bolted this plate in place below the > cracked > > area. > > > It would be out of sight, and providing considerable strength > for > > that > > > area. Would this be sufficient to bear the tension and give us > > our whole > > > piano back? > > > > > > Roger C. Hayden, RPT > > > Clarks Summit, PA > > > ________________________________________________________________ > > > > Roger, > > I've included a link to a site which promotes an intriguing and > > apparently > > extremely successful > > variety of cast iron repair. > > Haven't talked to them, but I understand that they have done piano > > > plates and > > consider their procedure highly appropriate. > > It might be worthwhile to check with them, regardless of what you > > ultimately > > do. > > Good luck! > > > > Greg Granoff > > > > Here's the address: http://www.locknstitch.com/ > > > > ________________________________________________________________ > YOU'RE PAYING TOO MUCH FOR THE INTERNET! > Juno now offers FREE Internet Access! > Try it today - there's no risk! For your FREE software, visit: > http://dl.www.juno.com/get/tagj. ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj.
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