Consolidating fossil fossil tree stumps

Suggestions for a suitable consolidant would be appreciated to help
protect some Carboniferous fossil tree stumps that are displayed
outside in a quarry. Some very fine details are preserved on the
specimens including bark and some fern fronds but they are suffering
quite badly from weathering. The quarry owners do not want to put
the specimens inside or cover them as they are part of a walking
trail around the site. They are on a very exposed south facing slope
and experience the full force of the English weather: cold damp
winters and warm (usually damp!) summers with the occasional dry
spell.

I gather that sealing them with a strong impermeable resin will not
allow the specimens to 'breathe' and this can cause the
crystallisation of soluble salts within the specimen--encouraging
the very 'spalling' that the treatment is intended to arrest.
Therefore I am looking for a suitable consolidant and solvent to get
the best penetration I can to provide the maximum strength and
resistance to weathering. All suggestions are welcome.

Nigel Larkin


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                  Conservation DistList Instance 25:39
                 Distributed: Friday, February 24, 2012
                       Message Id: cdl-25-39-023
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