Restoration of a Very Early French Harmonium: The Wind System Part 3: The Valve Board

The top of the valve board after stripping the neoprene gasket

I was going to cover both the valve board and the wadding in this post but it became clear that discussing them separately would work better. 

 

The valve board sits on top of the chest to which the reservoir is attached. Its function is to hold the valves that open each stop, making it the conduit for air to be forced through the reeds. When a valve is open the reeds for that stop can sound when the key is played.

 

As with other parts of the wind system cracks were present. I used my Japanese pull saw to widen and even out the cracks so I could splice in wood. When making a splice it is important to use the same or a similar wood, in this case a softwood such as spruce or pine. Pine was what I had at hand so that worked well. I glued in the splices, let them dry overnight, and used a small plane to bring the edges down to flush with the board on both sides. Then I shellacked the underside of the board. 

The overarching concern in the wind system is that it must be as airtight as possible. Any leak of air, however small, can compromise the function of the instrument when it is played. When looking for leaks I use a stethoscope so I can hear air escaping. Leaks can happen if a valve is not sealing properly, or a corner of a piece of leather is not glued down tight.

The underside of the valve board showing cracks

widening cracks before splicing

The valve board with splices

Restoring the valves was not difficult. I used two layers of lambskin, the top being thinner and dyed red, a traditional color for stop valves. I cleaned and polished all metal parts and reinstalled the valves. Each valve has a heavy spring to hold the valve closed until it is opened when a stop is opened.

The concern about air leaking is true with wooden parts of the wind system. A crack must be sealed so that air does not escape. The usual method of dealing with cracks is to determine if the crack can be closed by gluing and clamping, or if it must either be filled or covered with a leather seal. Wide cracks such as those I encountered here were beyond gluing and clamping.  It's a good idea to seal a filled crack with a leather strip if possible.

Restoration of the valve board complete

An unrestored valve with new leather

A valve re-covered with new leather

 In the next post I'll tackle one of the things that harmonium restorers dread the most--making new wadding!