Anatomy of a WurliTzer Theatre Pipe Organ
Stop Rails.
The straight Stop Rail that sits just above the top keyboard was much easier to get out, and a smaller job,
so it was done first.
This was the time to see what was under the finish on the console. With careful sanding the various
layers were removed to reveal the original veneer, in good condition. The veneer is much lighter than
the 70+ years of grime and shellac would suggest.
Fortunately the base board was drilled for an extra pair of pneumatics at each end so adding the Tibia Trem
tab only required adding an extra eyelet to the end of the tab pivot wire and the C-spring screw above the tab.
There was just enough wood left for the eyelet and the C-spring screw just fitted next to an existing screw
for the tab to go to the left (looking from the back) of the existing tabs.
The contact blocks, after being polished of course, had new silver contact wires fitted.
The baseboard was painted black as standard so it was sanded clean and refinished with two coats of
sealer/undercoat and the sprayed with satin black. Before the paint was applied the areas where the
pneumatice would go were covered with masking tape. Originally the pneumatics were stuck over paint
which does not work well unless you use burnt shellac as the glue which is not as easy to work with
before or after. When the masking tape was removed there was an area of clean wood onto which the
pneumatics could be glued. The bare areas also provided an obvious guide as to where the pneumatics
belong.
Before mounting the pneumatics the wiring was done so as to reduce the amount of handling that would
be required with the pneumatics in place and so reduce the chance of any accidents to the new leather.
It is also a lot easier to get to the contact blocks with a soldering iron without the pneumatics in the way.
The wiring was terminated on a "D-Sub" plug which was recessed into the side of the baseboard so the
assembly could be easily disconnected from the rest of the console to get it out of the way if neccessary.
The Horseshoe is a much larger job and very much more difficult to handle because of its size and shape.
The tin tubing that connects the preset blow box to the preset pneumatics
is glued into the horseshoe and
hangs down at an angle below the stop rail so it must be carefully positioned over the edge of the bench
to avoid any extra bends.
Unfortunately even thought the horseshoe preset blow box was built with five spare pairs of actions
and the straight rail was built ready for two more tabs the horseshoe itself was drilled for exactly the
original specification. To add the required exrta tabs meant drilling out the extra channels a long way
through the wood. This would have been easier if the cable channel had not been right where a tab action
needed to go. That channel needed to be filled and moved out of the way.
Drilling the holes over 200mm into the wood was always going to be interesting but it became more so
on about the third hole when about 100mm broke off the drill bit, about 100mm into the wood. Extracting
the broken drill required drilling several extra holes from the top of the horseshoe so that the bit could be
levered and poked and proded and pushed back out of its hole. The resulting mess was repaired by routing out
a channel surrounding the original hole, filling with a piece of timber and then redrilling the intended
hole through the new wood.
The horseshoe was then masked and refinished the same as the straight rail baseboard had been. After all the
fitting were in place the wiring was done and the pneumatics put in place.
There was enough wires left over in the 64 wire cable to the horseshoe to use for the straight rail so
the required wires were sleeved to form a sub-cable which will hang off the horseshoe and plug onto the
straight rail so all the stop tab wiring appears on a single cable.
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