ELAICH - Educational Linkage Approach in Cultural Heritage. For more information and presentations, please visit: http://elaich.technion.ac.il/ How should it be done? Guiding principles in conservation

1. Educational Linkage Approach In Cultural Heritage Prof. JoAnn Cassar and Roberta De Angelis – University of Malta The Conservation Process Module 4 Basic Cour s e Teaching Material Topic 4.3 How should it be done? Guiding principles in conservation Educational Toolkit

2. Educational Linkage Approach In Cultural Heritage Copyright ©ELAICH Beneficiaries 2009-2012 This material is an integral part of the “ELAICH – educational toolkit” and developed as part of the project ELAICH – Educational Linkage Approach in Cultural Heritage within the framework of EuroMed Cultural Heritage 4 Programme under grant agreement ENPI 150583. All rights reserved to the ELAICH Beneficiaries. This material, in its entirety only, may be used in "fair use" only as part of the ELAICH – educational toolkit for the educational purposes by non-profit educational establishments or in self-education, by any means at all times and on any downloads, copies and or, adaptations, clearly indicating “©ELAICH Beneficiaries 2009-2011” and making reference to these terms. Use of the material amounting to a distortion or mutilation of the material or is otherwise prejudicial to the honor or reputation of ELAICH Beneficiaries 2009-2011 is forbidden. Use of parts of the material is strictly forbidden. No part of this material may be: (1) used other than intended (2) copied, reproduced or distributed in any physical or electronic form (3) reproduced in any publication of any kind (4) used as part of any other teaching material in any framework; unless prior written permission of the ELAICH Beneficiaries has been obtained. Disclaimer This document has been produced with the financial assistance of the European Union. The contents of this document are the sole responsibility of the ELAICH Consortium and can under no circumstances be regarded as reflecting the position of the European Union. Prof. JoAnn Cassar and Roberta De Angelis – University of Malta

3. Abstract Educational Linkage Approach In Cultural Heritage A conservation intervention is often required to preserve works of art and buildings in the best possible condition. Conservation treatments, however, even if done with the best of intentions, entail some risks. Conservators work very closely with the materials making up works of art or buildings. They remove some materials from them – like dirt – or add new materials, which are usually meant to last for a long time. Wrong choices or decisions may lead to permanent damage to the works of art either in the short and/or in the long-term. For this reason conservation treatments follow specific “guiding principles” – meant to minimise the risk of making mistakes – and are carried out by professionals. Let’s see some of these principles... Prof. JoAnn Cassar and Roberta De Angelis – University of Malta

4. How should it be done? Prof. JoAnn Cassar and Roberta De Angelis – University of Malta Educational Linkage Approach In Cultural Heritage Works of art that conservators treat are irreplaceable. The task that conservators undertake is challenging: saving works of art through delicate treatments which must be carried out carefully to ensure that no permanent damage is done during the intervention and in the long-term.

5. How should it be done? Educational Linkage Approach In Cultural Heritage Treatments can involve taking materials away (dirt, old repairs, etc.) and/or adding materials (e.g. chemicals, water, cleaning agents, adhesives, etc.). © Photo courtesy of Din L-Art Ħelwa © Photo courtesy of Din L-Art Ħelwa I am performing tests to remove dirt from a statue through the application of chemicals I am injecting (adding) a material to stabilize a wall painting

6. Let’s see some examples… Prof. JoAnn Cassar and Roberta De Angelis – University of Malta Educational Linkage Approach In Cultural Heritage Both adding materials and taking materials away can imply risks to the object/monument if treatments are not carefully planned and carried out (especially in the long-term!).

7. Mistakes done in the past and sometimes even today…  Educational Linkage Approach In Cultural Heritage The application of cement to weak historic structures causes in the long-term the deterioration of the original masonry materials (bricks in this case). The application of iron clamps to strengthen walls causes in the long-term the deterioration of the masonry since iron oxidizes, expands and breaks the surrounding stone. Use of cement Use of metal clamps/dowels

8. water repellent surface (the water-repellent material penetrates inside the stone for a few mm). Water dissolves and transports salts, carries pollutants, and is essential for the growth of micro-organisms and vegetation... So keeping water away through the application of a protective coating (water repellent) seems to be a good idea... Unless salts are a problem...  Water + (dissolved) salts salts tend to crystallise just behind the water-repellent surface causing the detachment of the outer stone surface. Educational Linkage Approach In Cultural Heritage Mistakes done in the past and sometimes even today…  surface coated with a protective (water repellent) coating drops of water water evaporates but salts remain behind

9. Cleaning Educational Linkage Approach In Cultural Heritage Both taking materials away and adding materials can imply risks to the object/monument if treatments are not carefully planned and carried out (especially in the long term!). Cleaning can take some of the original material away if done with inappropriate tools or cleaning agents. This wall was cleaned using an aggressive inappropriate method... Which has taken away the dirt but also the original stone surface (look at how rough the surface is!). original surface before cleaning original surface after cleaning © Photos by Chanelle Muscat (1997) Cleaning trial © DECO http://www.inkspinster.com/ink.htm

10. Adding conservation materials can actually cause problems in the future if the material reacts chemically with the object being treated, if it changes its properties, or it ages badly and induces further damage to the object being treated. Consolidation stone before consolidation stone after consolidation A bad consolidant may bring along serious problems in the short but also in the long term as a result of its ageing! For example it might alter the colour of the original material. © Photos and experiment by Janice Borg (2011)

18. Educational Linkage Approach In Cultural Heritage This is an ageing test (salt crystallization test) to evaluate the behaviour of one type of mortar/plaster with different types of stone (click once to start viewing the test in progress). plaster stone Let’s see one example... © Photos and experiment by Elizabeth Muscat Azzopardi (2011)