Stabilizing a fossil in a friable shale

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Folks,

This question stems from a real collecting situation where I lost a
beautiful crinoid that was weathering out in a friable shale and was
wondering if there was something I could have done to have stabilized
the matrix. Since I go back to that site every couple years, I would
like to go prepared to do a better job.  

In any case, I was collecting with a paleontology class in the
Mississippian (Gilmore City Quarries) here in Iowa. There was a
beautiful little crinoid with about a nine inch stem still attached.
While the fossil was still complete, it was in a very small pocket of
friable shale of about half an inch in a very hard limestone.  The shale
was flaking and the fossil would soon have weathered into pieces.  I
tried to careful chip it out, but as I feared the shale was too
weathered and it fall apart.  

The question is was there something that I could have added to the shale
right around the fossil to have held the matrix together.  Three
possibilities come to my mind.  Would a dilute Elmer's glue solution or
duco cement penetrate a shale like this and stabilize it? I know both
are used for various other paleontological applications.  Just to make
matters worse it was slightly below freezing so the puddles there had a
bit of ice on them.  Would another possibility have been dilute plaster
of Paris?  But, even if that is a good choice, would it penetrate and
harden well in colder temps.     

Any suggestions would be appreciated.  One hates to lose a nice teaching
specimen when one could have saved it. 
-- 
James F. Mahaffy                   e-mail: mahaffy@dordt.edu
Biology Department                 phone: 712 722-6279
Dordt College                      FAX 712 722-1198
Sioux Center, Iowa 51250