Sustainable solutions for restoration & conservation of pipe organs by using Plasma Ion based surface engineering vs. EMA copolymer surface treatment techniques.

Pipe organs with their unique sound and beautiful housing are important objects of the cultural heritage. The instrument consists of a number of pipes (flute and reed), which are prone to heavy corrosion attack, resulting in a loss of voice. The atmospheric corrosion of reed (CuZn alloys) and flute pipes (PbSn alloys) is strongly enhanced by traces of volatile organic compounds (VOCs) and the alloy’s instability.
Experiments have been undertaken to explore the improvement of an aqueous corrosion with the high acetic acid concentration (2–5 v/v%) of CuZn and PbSn alloys, by deposition of protective films (Al2O3 and Al) in nano scale using Pulsed laser deposition and Magnetron sputtering. Afterwards, the samples were implanted with N+ ions using plasma immersion ion implantation. Such coating is then able to withstand stresses and vibrations due to sound generation in organ pipes, and it produces a barrier to VOCs and water vapor. Furthermore, for the treatments of new or slightly corroded flute pipes, solution of 4% Paraloid B-72 in toluene has been applied as corrosion inhibitor. The complete and overall application of the PB-72 improved significantly the corrosion resistance of flute pipes. The laboratory corrosion tests were combined with field studies at affected church organs.