Anatomy of a WurliTzer Theatre Pipe Organ
The rails that run across the centre top and bottom of a manual chest
are a potential problem source for leaks between adjoining ranks.
These joins are not always perfect so gaps may be present.
As the inside of the chest was being shellaced extra shellac was
run into these joins. In some cases the shellac ran out the other
side. Repeated coats caused the leaks to stop. The gaps were not large
enough to allow glue to be forced around all the corners and a leather
strip around all the corners would be difficult. The shellac is liquid
enough to wick its way around the corners and will fill all the small
gaps. It will shrink as it dries but the next coat will have a smaller
gap to fill until it forms a complete seal.
These leaks have no effect when the adjoining ranks are on the same
regulator and trem system but they are very important when the
adjoining ranks are supposed to be seperate. A very small leak will cause
the trem from one chest to effect the other chest causing a rank with the
its trem off to have an unexpected trem. If both trems are on it will
be impossible to get either to behave properly as each will effect the other.
If the chests are on different pressures e.g. the Vox (6") next to a Flute
(10") the higher pressure will slowly pump up the lower pressure regulator
above its correct pressure until the trem is turned on or some pipes are played.
All these problems can be very mysterious and confusing when there is no
obvious way that the two wind systems could possibly be joined, but quite obvious
when you work out what is going on. It is best to avoid confusion by ensuring
that these problems do not happen.