Lois

I haven't used Apiezon Q. But for semi-permanent sealing (of cracks in
glass lines and of ground glass joints) have found that the black wax -
Apiezon W (softens at 80-90 C; vapour pressure <10-8 mbar at 20C) -
maintains good long-term vacuum with no side effects I am aware of.

Tim Heaton

NERC Isotope Geosciences Laboratory
British Geological Survey
Keyworth, Nottingham NG12 5GG

Tel. +44(0)115 936 3401
Fax +44(0)115 936 3302
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