EXTRA! EXTRA! Plate Repairs- THIS COULD BE IT!

[Tony Caught]

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Robert,

Firstly, I am not knocking the idea as it appears to be a vast =
improvement on the original but,

In an old PTG journal (about 20 years ago) there was an article with =
photos about repairing cracks in iron frames.   From memory, the method =
used in that instant was very similar.  Holes drilled and threaded and =
screws inserted.  The piano tuner who did this was from South Australia. =
(thats the country down under)
Can't remember his name but maybe some oldtimer who has got all the old =
editions of the Journal on the list will remember the article and be =
able to look it up.

I have found through my  years of working on pianos that many seemingly =
new ideas and concepts have been done before, and we are now =
rediscovering them.

Regards

Tony Caught  caute@accessnt.com.au=20
    -----Original Message-----
    From: Robert Goodale <Robert.Goodale@NAU.EDU>
    To: pianotech@ptg.org <pianotech@ptg.org>
    Date: Wednesday, 16 December 1998 3:33
    Subject: EXTRA! EXTRA! Plate Repairs- THIS COULD BE IT!
   =20
   =20
    While at Yamaha an amazing new method for repairing cracked piano =
was shared by another member of the group.  This is a completely new =
technique and is unlike anything previously discussed.  This group =
member also brought a video tape for show and tell which put everyone in =
awe.  Even LeRoy was dumbfounded and is now wanting more information.=20
    This is no joke folks, read on...=20

    This crack repair method was developed originally for repairing =
cracked cast iron engine blocks and other heavy machinery.  It involves =
no welding whatsoever.  Instead a series of very specially designed =
screws are inserted into the crack which quite literally pull the crack =
together stronger than it was before.  When the repair is complete it is =
almost invisable.  This may sound to good to be true but the tape =
demonstrates this clearly.  Two flat pieces of cast iron were fastened =
together in a butt joint by a single one of these screws, and was then =
hooked on each end with a heavy chain.  The chain was then connected to =
a wench which lifted a 350 pound engine block.  The bond held perfectly. =
 A complete series of pins overlapping in a crack seals the crack =
permanently and stronger than it was originally.  On bench tests these =
repairs were shown to be completely air tight at 80 PSI.=20

    Ok, so here's how it works.  The screws are designed to dig in to =
the cast iron.  They must go into a pre-drilled hole using a special =
bit. The holes are also taped. The secrete is in the screw threads which =
are cupped sharply upward.  The top half of the screw has a countersunk =
collar which pulls tightly into the hole in the opposing direction of =
the cupped threads.  The screw is driven into the cast iron using an air =
drill until the torque breaks of the head.  The result is that the cast =
iron is clamped tightly together *internally*.  A series of these screws =
are installed to follow the crack side by side.  Then an overlapping =
series of screws are inserted in a second pass. The remains of the =
torqued-off heads are ground away smooth.  No welding, no mess.  This =
type of repair can even be made inside the piano without plate removal.  =
There are several types of these special screws which can be used on =
various types of cracks, even on angles or in corners.  They are also =
available in various lengths.  The video presentation was extremely =
convincing and had us talking about it for the remainder of the week.=20

    This group member's local chapter recently decided to try this =
repair as a joint project.  The inventor of this technique was =
personally present and assisted in explaining and then demonstrated the =
repair.  This proceedure is brand new and this was the first such repair =
made on a piano.  I think we can all pretty much expect to hear a lot =
about this very soon.=20

    This repair system is called the "CastMaster" by a company called =
Lock-N-Stitch.  They do have a web page.  Check it out and be amazed.=20

    Lock-N-Stitch=20

    Follow the link to "Information about Cast Master".  After you've =
read the text and looked at the pics, go to the link that demonstrates =
the complete repair.=20

    Enjoy!=20

    Rob Goodale, RPT=20


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