Custos Aeris: New evaluations for the preventive protection of historical lead glazing (Part 3)

Risk Temperature and humidity alternating stress


Risk of thermal cycling

Thermal cycling around 0 degrees Celsius leads to the formation of ice and condensation. Solid and liquid phases change constantly. This leads to mechanical damage to the gel layer and cracks, crusts, cracking and detachment /Hör 06/. There are still no limits as to how often this may happen per defined time unit except "as little as possible". The following diagram shows the number of changes per time unit for protective glazing in a cathedral:

Number of Thermal Cycles around 0 degrees C


Risk of moisture cycling

Moisture cycling around 80% leads to salt crystallization, cracking of the gel layer and intensification of corrosion /Hör 06/. Here too, there are no limit values, so that again the number of changes per unit of time is shown:

Number of moisture Cycles around 80% relative humidity


References:

Garrecht, H., Hahn, O. & Kappes, K. e., 2010. model test for gap temperature control at the Divi Blasii church in Mühlhausen, Germany, s.l.: s.n.
Hör, M. u. F. A. e., 2016: Possibilities of climate stabilization for stained glass collections damaged by anthropogenic environmental influences using the example of St. Sebald in Nuremberg, Nuremberg: St. Sebald, Nuremberg.
Hör, M. u. S. J., 2006. building physics investigations on the endangerment of the stained glass inventory in Nuremberg's Sebalduskirche, possibilities and limits of the effectiveness of exterior protective glazing, Nuremberg: s.n.
Schumacher, C. M., 2010. The glazing of the Protestant St. George Chapel in Fuhlenhagen, Koblenz: Büro Dr. Rauch.
Torge, M., 2011: "Exemplary evaluation of restoration and conservation measures for historical glass paintings with severe damage caused by anthropogenic influences", Berlin: Final report DBU Az 27312-45.


Acknowledgement:

This work is a separate continuation of the DBU project DBU file number 30751 "Development and exemplary application of a new sensor system for monitoring the sustainable effectiveness of protective glazing for stained glass endangered by anthropogenic environmental influences using the example of the Wiesenkirche in Soest", which was funded and completed by the DBU. We would like to take this opportunity to thank you once again for supporting the project.

Contact person: 

Michael Robrecht, iXtronics GmbH, Paderborn
Hans Daams, Hajuveda Heritage, Monschau

Direct contact: 

hans.daams@hajuvda.solutions
michael.robrecht@ixtronics.com

Web addresses: 

https://www.hajuveda.solutions
https://ix.ixtronics.com/de/

Blog: 

https://custosaeris-d.blogspot.com

Kommentare

Kommentar veröffentlichen

Beliebte Posts aus diesem Blog

Unsere neue Webseite ist fertig: Schimmel und Kondensat in historischen Gebäuden Schadenvorbeugung, Schadenerkennung und Schadenkontrolle

Das Klima ändert sich in den nächsten Jahren deutlich. Lufttemperatur und relative Feuchte fuehren zunehmend zu Schimmel und Kondensat. Der durch Menschen mitverursachte Klimawandel wird bis zum Ende des Jahrhunderts nicht nur die mittlere Lufttemperatur erhoehen, sondern auch zu einem erheblichen Anstieg der relativen Luftfeuchte fuehren. Dies bedeutet unmittelbar eine Bedrohung der Innenausstattungen von Kirchen und anderen historisch wertvollen Kulturguetern. Feuchte Luft in Kontakt zu kalten Objekten fuehrt zu Kondensation von in der Luft geloestem Wasserdampf. In Kirchen und anderen historischen Gebäuden speichern die massiven Wände die Kälte des Winters und der Nacht. Im Sommer, wenn warme feuchte Luft durch falsche Lueftung ins Innere der Gebäude gelangt, kann dies sogar zu Nebel und/oder Schwitzwasser fuehren. In vielen Fällen ist dies die Ursache von Schäden z.B. an historischen Glasfenstern, an Altären, Orgeln, Gemälden, Schreinen, Teppichen und sonstigen Objekten. Das Risiko...
Mehr anzeigen

11th Forum for the Conservation and Technology of Historic Stained Glassin Girona/Barcelona: Paper_ 1_1_by Hans Daams and Michael Robrecht

 Preserving Identity  11th Forum for the Conservation and Technology of Historic Stained Glass Girona – Barcelona, 7–9 July 2022  Organized by the Catalan Committee of the Corpus Vitrearum in Association with the International Scientific Committee for the Conservation of Stained Glass (ISCCSG) Lecture session 1: chaired by Ivo Rauch Paper 1.1. Schutzverglasung: ein thermodynamischer Rückblick auf die letzten 30 Jahre, Erfolge, Misserfolge und Schlussfolgerungen für zukünftige Projekte von  Hans Daams (Hajuveda-Heritage) und Michael Robrecht (iXtronics) Link to our Cloud: https://1drv.ms/b/s!AoHAta94EDU2gYo_-OmdQsHGWKxtqA?e=QGkoMq
Mehr anzeigen

How can cultural heritage be managed in times of climate change? Conference Bamberg, Germany, Date: February 27th/28th 2023

Long-term measurements of climate in the dome of Xanten and measurements on historic surfaces to predict damage risks on historical windows and mould risk on several historic altars in Xanten Johannes Schubert et.al. (cathedral builder Xanten), Rolf Becker (university Rhein-Waal)  and Hans Daams The current and future assessment of the indoor climate in Xanten cathedral and their effect on damages   of historical furnishings requires an extensive measurement strategy throughout the cathedral and on respective objects inside the cathedral. In cooperation with the university of Rhein-Waal this has been done now for more than three years.  This paper is focusing on in-situ measurements of historical surfaces. The valuable stained glass from the Middle Ages and the historical Petrus Altar are selected as examples of measurements and risk assessment. The impact of climate and sun on the protective glazing was measured for a period of 3 years. Data were collected for te...
Mehr anzeigen