There are a number of options for sealed environments.  Rubbermaid and other man
ufacturers make some wonderful containers for the restaurant trade in polyethyle
ne, polypropylene and polycarbonate.  These range from .5 gallon rounds to 5+
gallon rounds and even larger rectangular tubs, all with lids.  A closed cell ga
sket would be necessary for the rectangular boxes, but many of the rounds are ai
r-tight.  If you use a gasket, you will also have to devise a compression
 device
 such as a bunch of small C-clamps, screws and wing-nuts, spring clamps or whate
ver works.
 
If you are using silica gel as part of the environmental control, be very carefu
l that you do not allow it to run away on the high-RH side.  It can easily do th
at unless it is monitored very regularly and frequently.
 
Another alternative is to make a box from plexiglass and incorporate a flange to
 receive a gasket and a flat lid.  Again, closed cell gasket and some sort of cl
amping arrangement is necessary.  Plex allows you to examine the contents
without opening the environment, but it means some fabrication work.  Polycarbon
ate boxes are also transparent and allow you to view the contents.  The simplest
 solution would be the polycarbonate rounds with tight lids - if they fit.
 Good
 luck.  Call me if you need more info/advice.
 
Geoffrey Brown
Kelsey Museum
University of Michigan
313-747-0439
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