De-salting mural paintings

Danish scientists have discovered a way of preventing murals in medieval churches from crumbling and disappearing altogether. . .

The salt content in the bricks causes the stones to change shape if subjected to temperature changes and fluctuating humidity levels. When humidity in the air is high, the salt dissolves causing the stones to warp over time. When the air is dry, the salt is pushed out of the bricks causing them to disintegrate.

Along with a colleague, Inge Rörig-Dalgaard, a PhD student at the Technical University of Denmark, recently developed and patented a new method of removing the salt and reconstructing the brick wall. The method will be tested on the murals in Our Lady's Abbey in Helsingør after Easter.

The method uses electricity to remove the salt from the medieval bricks. A row of electrodes are placed on the ceiling of the abbey and an electric field is established that creates ion movement and extracts the salt out of the stones.

Posted by David on March 12, 2008 8:33 PM