Preserving bricks

Jonathan Farley has asked about preservation of a crumbling brick.
It is not clear from the description why the brick is deteriorating,
but soluble salts in the brick could be a problem. Look for
crystalline deposits or a whitish haze on or in the brick. If any
are observed, it would be a good idea to test for chlorides. The
presence of chlorides would indicate salt contamination. The remedy
for this (if the brick is strong enough) is long term soaking in
distilled water to remove soluble salts. Repeated changes of water
are necessary to remove salts from the wash water. (The brick might
need to be bound together with a water-permeable material to support
it during washing.) After washing and complete drying, it could be
consolidated.

After washing, or if there are no salt problems, the brick may be
strengthened by consolidation with a solution of B-72 acrylic resin.
A dilute solution such as 5% to 10% wt./vol. in solvent should
penetrate fairly well.  The solvent choices include xylenes,
toluene, ethanol and acetone. The latter two evaporate fairly
quickly and would not penetrate as well. The consolidant may be
brush applied or dripped onto the brick with a pipette. Repeated
applications may be needed. Broken off pieces can be adhered with
concentrated B-72 in acetone (1:1).

A stable relative humidity, possibly on the dry side, should help
preserve the brick.

Laura Reutter
Associate Conservator of Objects
Indianapolis Museum of Art

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                  Conservation DistList Instance 10:71
                 Distributed: Monday, February 10, 1997
                       Message Id: cdl-10-71-004
                                  ***