Flue pipes
Resonators for medium-size and large pipes are cut with a high-precision cutting machine. The work is faster and cleaner for such a big job, and extremely precise.
The pipe mouths are marked by hand over the inside surface of the still flat pipe resonators, in such a way that the clearly defined design of the upper lip will appear on the opposite side.
Pipe metal is soft and quite malleable, and smaller pipes can be rolled around mandrels by hand. A tapered mandrel is used to form the toe of a pipe. The metal is beaten until it conforms fully to the shape of the mandrel.
Larger pipes are rolled around machines which have been specially adapted to Ruffatti’s requirements.
The surface of the metal is protected with sizing made by Ruffatti with gum arabic. The pipe maker bevels the metal edges which will be soldered, removing the sizing only where necessary. By doing this, the solder will only flow and stick where there is no sizing, creating perfectly even solder seams. This process is exclusively done by hand, and it has remained unchanged over the course of centuries.
Pipes are then washed and rounded by hand. Steel burnishers are used for the larger ones.
At the end of the process, all pipes, large and small, are individually hand polished.
Eight-foot pipes which will never be visible, placed inside the organ, are nevertheless manufactured with the precious 95% tin alloy. Their appearance, mechanical resistance, and tonal qualities are extraordinary.