Removing cement from ceramic panels

We de-installed 19th century Persian wall fountain ceramic panels
(four panels, each about 67 x 52 x 5 cm) from Islamic Gallery at The
Detroit Institute of Art. We discovered that the cement (5 cm
thickness and over 100 kg with two panels) with a metal mesh
reinforcement has been previously applied to the backside of the
panels during the de-installation.

We decide to remove the cement from the panels because the cement is
cracking away from the back of the panels, and the previously
reassembled panels began to loosen while they were being removed
from display on the wall.

I have begun to remove the cement from the back side of the panels
using chisels, a hammer and a hacksaw. I found that the ceramic body
is very soft and porous while the cement is very hard and dense. I
am concerned about giving the vibration to the object, even thought
the object is padding with polyethylene forms to absorb some
vibration. Also this method is time consuming and physical work. Of
course, I do not mind that if this is the safest way for the object.

I would be grateful for any suggestions or examples of methods that
are currently being used, or have been used in the past for this
kind of problem. We have not discussed the acid treatment of
removing cement at all because of the dangers to the object and
conservators but I would be happy to know for the future reference.

Naoko Fukumaru
Mellon Fellow in Conservation of Decorative Art
The Detroit Institute of Arts
Center for Conservation
5200 Woodward Ave.
Detroit, MI  48202 USA
313-833-1728
Fax: 313-833-6406


                                  ***
                  Conservation DistList Instance 17:34
                Distributed: Thursday, October 16, 2003
                       Message Id: cdl-17-34-027
                                  ***