A 19C Debain harmonium - restoration of bellows

The past month or so has been devoted to restoring a Mason and Hamlin American reed organ for the Providence Chapel in Charlwood, Surrey and a Debain harmonium for a musician. This post will concentrate on the the Debain as I found it a particularly rewarding job.

The Debain harmonium is a small instrument of only one rank of reeds but it is well used. I did some basic restoration on it a few years ago but recently the bellows finally gave out and patches put on by the owner could no longer stop the leaks. The leather and paper were in all probability the original materials from the manufacture of the harmonium about 150 years ago, so they were well beyond their life expectancy. The leather was dry and perished and the paper was lifting in several places. Some of the leaks seemed to be coming from the windtrunks.

The harmonium is a very elegant and compact instrument ideal for transporting around for concerts.

The patching was fairly obvious

The bellows and reservoir assembly can be removed in one piece.The leather was so perished that the various parts could be easily separated.

At some point - probably decades ago - a mouse had the misfortune to run between the ribs of the reservoir as they folded, got trapped and was mummified.

The entire assembly was stripped down to bare wood as it was impossible to reuse any of the leather or paper.

The original blue paper had mostly faded but a few bits were sealed under leather retaining their original colour and it was possible to match some sheets of new paper. Some of the inner boards had been covered in either a beige sugar paper or a darker shade of blue paper so these were copied as well. This also shows the releathered safety valve inside the reservoir to prevent pressure build-up.

The wind trunks were leaking because of splits in the sides. They were so securely glued in that it was not possible to remove them without some damage. New windtrunks were therefore made using salvaged 19C timber.

The feeders and reservoir were completely releathered and covered in new paper following the original pattern

The feeders have springs inside them so that they refill quickly with air.

Once all the component parts are reassembled it is beginning to look like it might have done when the harmonium left the Debain manufactory in the 1870s 

Once the reed board and action parts are reassembled the reservoir can be filled. This photo shows the reservoir at almost maximum extension against the two springs that regulate the pressure.

The harmonium is currently tuned to A=438 so the next job is raise the pitch to A=440 but for the moment it is going back to owner for the next concert and the retuning will have to wait for another day.