As is the case of most musical box collectors, I have piles of rusty
discs that came with various size disc machines I have in my possession.
One pile contained some Polyphon 8-1/4" discs and amongst them were
about five Christmas tunes with all projections in place but with the
titles barely readable or worn completely and caked in rust.

In the past I've tried many methods to remove the rust but retaining
the title.  The most successful method I've found is immersing the disc
in a solution of water and citric acid and watching carefully while
gently agitating the solution and using a soft nylon brush to rub the
surface so as to retain as much of the title as possible.

However; with the 8-1/4" discs any hope of retaining the titles was
impossible.  I scanned each disc on a flatbed scanner and replicated
the artwork and lettering using Adobe PhotoShop to create an accurate
template that could be cut with a vinyl cutter to create a stencil.
Luckily, PhotoShop and similar digital image editing programmes allow
you to stretch and distort lettering fonts to closely match the
original lettering style.  The discs were stripped completely back to
bare metal in preparation for re-titling.

Now the real point of this enquiry is how to deal with the dished and
distorted metal in the centre of the discs.  8-1/4" Polyphon discs are
centre driven.  I've read that by applying heat to the metal can shrink
it and hopefully flatten it but I'd like to hear from anyone who has
had success with this method.  The discs are coloured brown with yellow
lettering.  The brown colour is shellac and the discs were most likely
dipped in coloured shellac before being screen printed.  My method
will be to spray the yellow titles and artwork through a stencil.

Has anyone replicated the brown coloured shellac?  If so, I'd like to
know so as to save me time with experimentation.  I will post pictures
once the discs are completed.

Mark Buckland