An Adventure

[Roger Jolly]

Hi Newton,
                It's been a long time sine I have done one of these
beasties. but the shelf is probably the culprit. I have had very good
success by replacing with good quality Balkan Birch plywood. 
 It's fairly easy to duplicate. clamp the new piece and old shelf together
and drill through using the old stock as a template. If there is room add
some stiffeners. Most of the Canadian pump organs use a spruce or fir 3 ply
shelf, and delamination is a common source of problems. The air escapes up
the screw hole along the lamination to the side of the shelf over a wide
area, and is difficult to detect.
Darn these things can be humbling.
Regards Roger



At 09:22 AM 16/01/99 -0500, you wrote:
>Dear List Mates
>
>Last summer I committed to refurbishing the bellows of a Mason & Hamlin
>two rank reed organ.
>
>The reservoir materiel was bad but the exhausters were made by gluing
>fine leather to stiff cardboard.  The leather was in good condition and
>without leaks.
>
>I replaced the reservoir material, the exhauster webbing and reassembled
>
>the organ, which then played fairly well, and it had an acceptable
>vacuum hold duration.
>
>I got a call from the customer, who is a metallurgist and not a
>musician, to the effect that the organ will not hold a vacuum.  I got
>there and it did not indeed hold a vacuum.
>
>Since the weather has been cold, the heat has been on a lot, I thought a
>
>board or panel had split.  I could see nothing wrong so I disassembled
>the organ, with dread, but I needed to solve the problem.  The bellows
>system was as tight as when I reinstalled it, so I looked at the sound
>chamber more closely.  No obvious leaks or splits, but the two parts did
>
>not meet evenly all around.  No real problem there because there are
>twenty screws holding them together.  A power screw driver is a must!
>
>I started to reassemble the organ. And I reassembled it, took it apart
>for some reason or other for two days. Just to find a leak.  No leaks.
>I used a stethoscope around the edges, no leaks.  When I finally got it
>together it still will not hold a vacuum like it did in the summer, so I
>
>can only conclude that the drying of the wood opened micro cracks and
>that the gasket material, long strips of buckskin, leaks some but not
>enough to be heard with a LOUD stethoscope.
>
>I hate these things.  He asked why I do them and I said that about every
>
>7 to 8 years I have to acquire a bit more humility, just enough to keep
>me honest and teach me that I do not know everything.
>
>I will accept comments about the organ but I will not accept comments on
>
>my character deficiencies.
>
>One winter adventure too many, so far.
>
>Stay warm and dry.
>
>                Newton
> 
Roger Jolly
Baldwin Yamaha Piano Centre
Saskatoon and Regina
Saskatchewan, Canada.
306-665-0213
Fax 652-0505