Deliverables
A pneumatic valve has been developed for installation in the organ wind system (wind trunks and windchests) in order to automatically ventilate the organ before start playing so the wind containing accumulated organic acids will be evacuated.
4 valves have been manufactured and installed in the pallet boxes in the windchest in a case study using the historical Stellwagen organ in St. Jakobi church, Lübeck, severely affected by corrosion.
The valve is already a product, available from the owner of this result.
Potential users or customers are organbuilders and organ restorers that want to install the valve as one of the actions included in the conservation strategy in order to impede a corrosive environment in the organ.
The availability of this valve will be disseminated through education of organbuilders and the owners of the instruments suffering from corrosion at conferences and seminars, in articles and by the project Web site. It will also be presented in a publication including a scientific/popular report and guidelines for a conservation strategy produced by the project consortium.
The European heritage of the organ is preserved in numerous historical instruments. One major threat to this heritage is the indoor atmospheric corrosion of lead and lead-tin alloys of organ pipes. In order to save the corroded pipes, cleaning the corroded pipe metal surface is a part of the conservation procedure. Cleaning the corroded pipe is done primarily to decrease the rate of corrosion by removing corrosion compounds (salts) from the surface. The insoluble corrosion products (e.g. lead white) are not to be removed. Cleaning should not affect the metal itself.
Water leaching of corroded pipes (foot area) is a method to remove corrosive compounds. Ultrasonic agitation may be used and decreases the leaching time somewhat. The leaching time depends on the extension of the corrosion attack and shape of the pipe foot. However, it is not advisable to clean the corroded pipes with water if the environment is still corrosive.
The method is intended to be used by organ restorers as a part of the conservation process of corroded organ pipes.
The dissemination is performed by seminars and workshops.
A method to take samples from corroded pipes has been set up. This method has been used in order to get samples for the study of microstructure and composition of corroded pipes as well as for the identification of corrosion products. No method had been previously defined for this kind of studies, apart from a few recommendations in order to preserve the microstructure of the metal.
The aim of our method is to get maximum information from the sample at minimum damage for the pipe. Suggestions for cutting the pipe without deforming the pipe itself and the sample have been proposed. A method to subdivide the sample for non-destructive analysis of corrosion products, microstructural and chemical analysis of the metal and observation of corrosion products in cross section has been set up.
This method may have potential applications in the field of corrosion studies on flue pipes; the method can also be modified in order to be used for other ancient lead objects. Researchers who study metal antiquities can be potential end-users of this method. Also restorers who provide samples to researchers may be interested in how to take samples according to this method. The description of the method in scientific publications can be used to disseminate this result.
A unique method to map the environment inside the organ has been developed within the project. The method provides information on the presence of potentially corrosive gases in the wind system. The concentration of organic acids, aldehydes and volatile organic compounds is measured using both active and passive sampling. Before each measurement the organ was not played for five days. This was done in order to simulate the situation where the concentrations of organic acids build up inside the organ pallet box when the organ is not played. This method may be used to analyse the environment inside an organ, in order to predict if a certain organ is at risk for heavy corrosion. This new technique will be disseminated by publishing a detailed description of it in scientific journals.
Different methods for the protection of both corroded and uncorroded lead objects have been considered, on the basis of a survey of the literature on surface treatments for the protection of lead-based alloys. A set of candidate surface treatments has been applied on lead coupons. The protective efficiency of these treatments has been tested and compared.
The innovative feature of the result is the assessment and comparison of the protective efficency in acetic acid environment of treatments for lead conservation, selected and optimised with a view to the applicability on organ pipes in an organbuilding workshop. For this reason, the result of the assessment is of particular interest for organ builders and organ restorers who might consider the application of protective coatings on lead rich-organ pipes.
The results indicate that the application of protective treatments on the inner surface of the pipe foot is not advisable, since treatments may modify the geometry of the foot tip or the mouth area without guaranteeing adequate protection in long-term exposure to organic acid environment.
This result might contribute to safeguarding the original characteristics of historical organs. This result may have potential applications in the field of conservation of organ pipes. Seminars and workshops to potential end-users (organ builders and organ restorers) have been planned to disseminate this result.
Searching for OpenAIRE data...
There was an error trying to search data from OpenAIRE
No results available