Removing paint from concrete reliefs

As a student of the Limburg Conservation Institute (SRAL) I am doing
an internship at the 'The National Service for Archaeology, Cultural
Landscape and Built Heritage' (RACM) in the Netherlands. A part of
the internship involves the investigation of removing paint from
concrete surfaces (walls and ceilings) in a monumental building from
the 1950s. It also concerns several abstract concrete reliefs
(concrete has been cast with a wooden mould, creating a relief in
the concrete walls). According to the (now 84 years old) artist
these were intended to be unpainted, but in the past the reliefs and
the rest of the building have been "cheered up" with bright colours
of unknown types of house paints. Together with the owner and
renovating architect we are considering removing (all) the paint
from the concrete.

Conservation of concrete surfaces is a new field for me and I would
like to ask if someone has dealt with a similar situation before and
can give advise me or share his/her knowledge.

A few of my thoughts:

Would paint stripping be an option? Which paint strippers are
suitable for concrete surfaces? (Will a paint stripper leave
residues of paint and gel in the small gaps which may have
consequences for the concrete in the future?)

Would steam cleaning be an option?

In my view sandblasting would damage the skin of the concrete.

I would greatly appreciate any information or treatment ideas and
advice,

Annefloor Schlotter
Verwersdijk 65c
2611 NE Delft
The Netherlands
+31 6 42093421


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                  Conservation DistList Instance 22:7
                   Distributed: Friday, July 25, 2008
                        Message Id: cdl-22-7-013
                                  ***