Back in the mid 1980's I installed a Kimball pipe organ into (Nita)
Akin Auditorium in Wichita Falls, Texas.  The organ was built in 1935
and has a Kimball Welte Musicalle on it which plays 10 rolls at a time.
It has been constantly used for organ lessons and recitals since that
time.

I have also been going out there twice a year to tune and maintain it.
In over 15 years, it has only had one emergency service call.  Usually
any problem is small enough to wait until the next tuning trip.

A couple of years ago, I got a call that on my next trip, I should try
to find out why the organ was playing weakly.  We had kept rat glue
traps and bait out for years, but when I got there I discovered that
rats had moved in and had eaten the corner gussets completely out of
the first static reservoir.  I went farther into the organ and I found
another chewed reservoir and another, and another, and another.

Come to find out, I could not even tune the organ, every reservoir
was chewed except the reed static, which was way up high, and the Echo
Division at the other end of the building.  Every corner was chewed out
totally.  The rats did not bother the rib leather or any other leather
anywhere else I could find, but in the 80's when we rebuilt all these
items we used the standard tanned white leather and they seemed to find
that so delightful to chew.

I rented a truck and hauled 13 reservoirs back to the shop in St. Louis
and rebuilt them.  Some of them were the size of a good sized dining
table.  We got a new pest company and put out spring traps and more
bait and more glue traps thereafter.  All was well for a while.

Last January I got a call that the whole organ was running but the
console would not play anything.  My local professor checked the
winding and the power supply and both those were working.  I had to
make my first emergency service call.

Getting there, I found all seemed to be in order except for a few
pneumatic gang switches that turned the console off and turned the
Welte Philharmonic player on.  The rats had returned and chewed holes
in the gang switches I had recovered with vegetable tanned leather from
the 80's.

I noticed that the rats had been going strong through the organ but
had not chewed any of the new chrome tanned gussets.  They only chewed
gang switches.  None of the ones with chrome tanned leather were
touched, neither were the ones with original leather from 1935.  Only
the vegetable tanned fifteen year old leather was chewed.  I recovered
lots of them with chrome tanned pouch leather.

I will be returning next month to tune and we will get the pest man to
go with me to clean up the baits and traps, and replace them with new
ones.  It seems to me that chrome tanned leather is not inviting to
rats.  Old leather is only slightly more interesting to them.

I may try the ammonia but I wonder how often one would have to change
it.  My cleaners with ammonia all tend to off-gas the ammonia, leaving
colored liquid, unless they are kept airtight.

D.L. Bullock
St. Louis
www.thepianoworld.com