My buddy finally got his repaired Mills Violano plate back early this
week.  After the repair shop drilled two 1/8" holes at the end of the
crack to keep it from running it was brazed with nickel-silver.  Three
round steel pins were also placed along the crack to keep everything
locked into proper position.  Nickel-silver brazing rod, covered with
its own special flux, was then used on the entire length of the crack
along with the steel pins.

The crack was first blasted with glass beads to remove any rust
oxidation.  For the actual repair an old-fashioned oxyacetylene torch
(oxygen & acetylene) was used at a much lower temp than would melt or
harden the old cast iron plate.  The plate was first pre-heated with
two rosebud gas heating torch tips.  These were also used to slowly
allow the plate to cool for a half hour after the repair.  The flux
was then cleaned off the plate using bead blasting.

This shop has been repairing rare engine castings for brass era and
Antique/Classic autos for 25+ years.  Many have been irreplaceable
one-of-a-kind castings made of cast-iron or aluminum "unobtainium"
(you can't find them at any price!).  I had used this shop to repair
my 1926 Springfield Rolls-Royce Silver Ghost twin cylinder castings,
with several cracks in combustion chambers, freeze-up cracks and
rust-out pin-holes.  Reproduction machined castings would have cost
me $15000 each!  My repairs cost under $1000.

The repaired Mills Violano plate was re-painted after grinding and
feather-fill.  You cannot see the repair from the plate top!  New
piano wire and custom bass string set, as well as oversize tuning pins,
were installed.  The piano plate was slowly brought up to pitch in four
stages and did not re-crack or implode.  The total cost was $350 for
the braze repair of the "harp" plate crack.  We will now see if this
repair holds; we are still keeping our fingers crossed.

Brad Hunter