[ Ref. 180313 MMD, Seek Coin Piano Roll Repair Expert ]

I have repaired many rolls over the years.  Mostly edge repairs, but
I have done badly damaged and split rolls as well.  It is _very_ time
consuming.  I have a selection of electrical grade kraft papers used
for the insulation of paper insulated telephone cable conductors, and
the thicknesses range from 0.05 mm to 0.25 mm.

The most important requirement is that the paper be absolutely flat
after the repair, otherwise the paper does not get sucked onto the
tracker bar and leaks between the holes and causes multiple notes
to sound.  Although I have never done it, I believe the paper needs
to be laid out on a repair table which has a vacuum supply underneath
the paper to hold it flat.  The paper can then be aligned.  Then the
glueing needs to be done without disturbing the alignment.  We are
talking here about fractions of a millimetre.

The glue I use is a dilute PVA glue and this does allow the paper to
be moved around a bit after application, to give the correct alignment.

Rolls which have had the paper torn or crinkled are very difficult
to get flat again.  I have tried using a steam iron but with little
success.  I did repair a Recordo roll which was torn lengthwise over
a distance of about 4 foot.  The repair went okay until the region
where the repaired bit joined the unrepaired bit.  At that transition,
the roll was unable to lie flat on the tracker.  But at least the roll
is now playable.

I have seen many rolls repaired with plastic type tape materials and
invariably these repair tapes have a greater elongation than paper.
If the tape is applied with some tension, after time the tape shrinks
back to its original length and causes curling at the edge of the roll
so that the roll is, again, unplayable.

Paul Rumpf
Melbourne, Australia

 [ Wikipedia presents a good description of the kraft paper making
 [ process at https://en.wikipedia.org/wiki/Kraft_process  -- Robbie