I thought it might be time to add the perspectives of an archaeological
conservator to this discussion.  First, I'll address some of the specifics to
the information being dispersed about alternatives for the whiteout/nail
polish technique and then start in on my own soapbox.
 
Acryloid B-72 is an acrylic polymer produced by Rohm and Haas.  It is used in
the field of conservation for many different things both because it has been
tested and has been found to be stable, and two, it is a material that is very
flexible in it's "usability". Depending on how you mix it up with solvents you
can use it as an adhesive, coating or consolidant.  It has been tested.
Various references you can check (Jim Barnes) are:
 
Down, Jane L.  1992.  Adhesive Testing at the Canadian Conservation Institute
- an evaluation of selected poly(vinyl acetate) and Acrylic Adhesives.
Ottawa: Canadian Conservation Institute. (You can get if for free by writing
CCI, 1030 Innes, Ottawa, Canada, K1A 0C8)
 
Feller, R.L. (1979) Standards in the evaluation of thermoplastic resins, In
The International Council of Museums (ICOM) COmmitte for Conservation 5th
Triennial Meeting, 78/16/4.
 
Horie, C.V.  1987 Materials For Conservation.  London:Butterworths.
 
There has been alot of discussion in the conservation field about how to get
more interaction with archaeology.  Two years ago at the American Institute
for Conservation meetings there was a panel discussion of archaeologists,
conservators, and collections managers about just this question.  In my
opinion the problem is seated in the history of both archaeology and
conservation. Briefly, "archaeological conservation" as a separate field of
conservation developed in Britain along with British prehistoric archaeology.
In the U.S. conservation developed out of the fine arts and those people who
did archaeological conservation sometimes had never been in the field, or got
their field experience separate from the conservation training (though that is
changing in recent years).  Most of the people who do active field
conservation until recent years train in Britain (including me) and still do
most of their work in the Middle East or Europe (though historical
archaeological projects are an exception). In practical terms this means that
most archaeologists interact with conservators in the museum, usually after
the field season, and after most of the initial recording and "treatments"
(cleaning, gluing etc.) have been done.  In the U.S. many of the treatments
that are used have been developed by archaeologists (often in conjunction with
conservators.  But since there is not on-going intereaction in the field,
techniques and materials that have long been discounted in conservation are
still used in archaeology.  I think both conservation and archaeology are at
fault for this lack of interaction.  Conservators should publish in
archaeological journals and attend more archaeological conferences.  But there
aren't a whole lot of us.  Probably less than fifty in the U.S. who are
actively involved specifically in archaeological conservation, and work in the
field. So, archaeologists should also attempt to learn more about
conservation. There are several new texts, and some "continuing ed" courses
being taught at different institutions.  (If anyone's interested I can send
more info.)
 
This whole thread has been less about what's right or wrong and more about
information dispersal.  In small, poorly funded fields like ours it takes a
long time for information to spread.  Hopefully, with the Internet, some of
this stuff will disperse a little faster.
 
Jessie Johnson
Texas Memorial Museum
University of Texas at Austin.