Silica gel

George W Cannon <gwc4 [at] cornell__edu> writes

Barry Knight <barry [at] eng-h__gov__uk> writes

>It's important to be aware that standard silicone sealants out gas
>acetic acid as they cure.  Standard silicone sealants should only be
>used in a sealed case if the sealant is allowed to cure for several
>days to a couple of weeks.  A better bet is a "neutral cure"
>silicone.  These are available through major glazing supply houses
>such as C. R. Lawrence. Check with your local glass shop.
>

George Cannon is quite right: I forgot to mention that it is
important to use a silicone sealant that does not emit acetic acid
as it cures.  The one I used, which is available in the UK although
I don't know about elsewhere, is Ambersil sealant 1040N.

Barry Knight
English Heritage
London

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                  Conservation DistList Instance 10:35
                 Distributed: Saturday, October 5, 1996
                       Message Id: cdl-10-35-010
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