[ Ref. 060616 MMD, "Seek Piano Plate for Link Orchestrion"]

> I'm told welding is not practical.

Much to contrary belief, broken plates _can_ be repaired, and quite
successfully.  Beware if you attempt to install another piano into
the Link case, for the alteration will be permanent and the authentic
value will be lost forever.  Please, don't do this.

Cast iron has an exceptionally high carbon content.  This provides
tremendous strength but also makes it brittle.  Unfortunately in the
rare cases that one should break, repairs require special techniques
unlike traditional steel.  Cast iron expands dramatically when heated,
which is why it does not tolerate traditional welding.  Commonly, when
a crack in cast iron is welded, the expansion from the heat is unable
to return when it cools because the new weld has locked it.  Thus a new
crack forms shortly after it is stressed with string tension.

There are two practical ways to fix a piano plate and taking it to your
local welding shop is not one of them.  The first technique is called
"metal stitching."  Rather than repairing the crack, it is locked
together by machining out sections using a special template and then
inlaying a specially made plates that match to the recessed areas.  The
plates are slightly smaller so they are taped into place where they
will lock in place.  Special epoxy is also used.

A related technique is using special screws made for this that have an
upward curved thread.  They are countersunk into the crack itself and
when tightened the heads break off at a prescribed torque.  A series of
overlapping screws is typically used across the entire crack.  A special
epoxy is also used with the screws.

When these repairs are performed correctly it is amazing how strong and
reliable it will be.  I have done this and found it to work marvelous.
Once the repair is complete the area can be filled, (Bondo, glaze,
etc,), sanded, and when painted no one will know it was there.  This
technique was originally developed for repairing cracked engine blocks
and heads but has since been adopted by many different industries for
cast iron repair.  The leading supplier for the tools and supplies is
Lock-n-Stitch Inc.  Their web page is here: http://www.locknstitch.com/

The alternate technique requires heating the entire plate over the
course of a few days in a special oven until it is glowing red.  This
makes the expansion of the plate even.  A specialized welding procedure
is used to repair the crack and the plate is then allowed to cool slowly
over the course of a few days.  After grinding, shaping, filling, and
painting, the crack will be reliably fixed.  Needless to say, this is
a more complicated process but the metal is truly like new.  If this type
of repair is required the Lock-n-Stitch company can perform this as well.
They have the reputation of being the best in the business.

If your plate has already had a failed repair attempt it may have
been butchered beyond a traditional stitch repair and will require the
alternate method above.  The Lock-n-Stitch folks are very friendly and
helpful and will provide all the help you need.  If you send them some
pictures they can tell you where to go with it.  They also have a video
presentation they can send you that will demonstrate the stitching and
screwing processes.  You can crate and ship it to them and in a few
weeks you will get it back good as new.  Yes, it will be expensive but
you will have made a proper reliable repair and preserved the orchestrion
from a much worse fate.

Rob Goodale, RPT
Las Vegas, Nevada