Lime grout additives

Naomi Kroll <naomi_kroll [at] nps__gov> writes

>I am considering adding ethyl carbamate or ammonium carbamate to a
>lime-based stone grout, as described in P. Baglioni et al., "New
>Autogenous Lime-Based Grouts Used in the Conservation of Lime-Based
>Wall Paintings," Studies in Conservation 42 n. 1 (1997). ...

Carbamates are known carcinogens. I think you would be better off
using a sand and lime based material containing calcined kaolin and
trass flour. Both of these materials react with calcium hydroxide to
form calcium silicates and calcium aluminates which have
cementicious qualities, the kaolin reacts relatively quickly, within
2 to 4 days whist the trass reacts over a period of 1 or 2 years,
the resulting strength is similar to that of a well carbonated
render but achieved in a couple of years.

Edgardo Pinto Guerra
Westox Consultant for Europe


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                  Conservation DistList Instance 17:7
                   Distributed: Friday, June 27, 2003
                        Message Id: cdl-17-7-001
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