dendrup's chapel

The paintings were present in all the walls but one, where a wooden altar was standing. The entrance was given by a wooden separation wall, painted as well. The wooden ceiling was painted too and it was assembled with interlocking panels. The structural wall of this chapel was made of stones piled up apparently without binder. On top of the construction stones, a coating of clay mixed up with straw was applied to create the flat surface, hosting the pictorial layer. The thickness of this coating varied according to the voids left by the construction stones. One side of the pictorial cycle was painted on a wooden wall made of planks joined together with glue. The binder of the paint layer is water based in all the three painted walls. A water-soluble varnish was applied to protect the wall paintings. The paintings were extremely damaged and it could be guessed that the majority is lost forever. Somehow people tried a very rough cleaning in the past, thus producing a great loss of paint layer. Moreover the paintings still left are covered with a thin coating of clay. The preparatory layers were not sound and many gaps and detachments are present all along the surface painted on the walls. The wood was darkened by soot deposits of smoke.

The consolidation was carried out after the coating of mud had been removed. Toothbrushes were used together with the aid of specific fiberglass pencils for restoration to accomplish the task. The same procedure was employed to clean off the clay from the ceiling. The detached preparatory layers were fixed back to the stone based wall through injections of mortars and gluing solutions based on PVA binders. The small detachments were filled up with an acrylic binder emulsion in water. As for the deepest detachments, they were filled up with a mortar composed of local clays and PVA binder.

Tests were carried out to find out the most suitable clays to be injected. 2 kinds of clay were subsequently added with a PVA binder emulsion. Prior any injection, a surfactant solution was instilled through syringes. Where it was possible, existing cracks were used for the injections but in most cases, the paint layer had to be pierces using hand-drills with bits whose width varied from 1 to 2 mm of diameter. Care was taken while drilling in order not to damage important outlines, figures or inscriptions.

Since the amount of water in any mortar or solution will evaporate, some voids would still not sound still underneath the surface of the wall paintings. Thence, the consolidation was checked every few weeks for the whole length of the project and more injections were carried out where and when needed. It is to be underlined that a PVA binder may cause the mortar to be impermeable from a 20% based solution onwards. The use of a solution in a range of 10% still leaves the wall “breathing” without causing any damages to the stratification of the wall paintings.

Unfortunately the project was stopped in 2008 following a ban imposed by the Chinese Government in all Tibetan areas soon after the infamous riots broken out in Lhasa and Chengdu in occasion of the Olympic Games. All of a sudden foreigners were not allowed anymore to work in sensitive areas, thus influencing the destiny of this project. Later on the foundation supporting the project closed down and the project could never be finished.