In response to HHS Director, apparently you are using UV filtering Plexi
with no tinting. Unfortunately, when UV filtering Plexi or films first began
to be used in historic houses, the word did not get out adequately that
fading cannot be eliminated just by blocking out UV light. Sure, blocking UV
significantly reduces fading, but visible light continues to fade sensitive
artifacts, especially the high-energy blue light. I know of some historic
houses that installed UV blocking Plexi so that they could open the shutters
and pull back the curtains to let more light into dark rooms. In so doing,
the probably did little to extend the life of the collection and may even
have caused more light damage to sensitive collection artifacts. So the
standing recommendation from conservators is now to not only filter out all
of the UV, but also filter out us much of the visible natural light as you
can tolerate (yes, I know, the "black box" concept). How much window tinting
a room can tolerate is not determined by how the view out the windows
appears. One can see outside surprisingly well through a 90% tint,
especially if it is a warm bronze color. However, 90% tinting on all the
windows will make the room very dark inside, so more artificial light needs
to be added in the room to make it work. Even using 50% tinting on the
windows, which is hardly noticable when viewing outside, darkens the room
noticeably. Adding back tungsten or halogen lights to accentuate important
artifacts in the room significantly improves the appearance of the interiors
while exposing artifacts to only a fraction of the light that was entering
through the windows. We find that several 25 or 50 watt BAB (flood) MR16
lamps are all that is need to pleasently illuminate our average sized
historic house rooms. Of course, if you are trying to interpret your room
historically to including historical lighting that came mostly form the
windows, this lighting approach will not work.
Moisture between the Plexi and the windows can and should be prevented by
installing a "P" or "D" shaped silicon gasket on the back side of the Plexi
sheet around all 4 edges. This is the type of gasket that is used to
weatherproof a door as it closes on the top of the"P" bulb forming a good
seal. The gasket comes with a self adhesive backing that can adhere directly
to the Plexi, and the bulb seals against the wood stop molding.
Unfortunately, the bugs are probably coming in through the loose historic
windows. It is best to restore the historic windows and seal well around the
edges before interior storms are installed. We have found that Mortite
caulking cord works well and remains reversible, although if the paint
around the window is flaking, the Mortite will pull it of when it is
removed. A clear acrylic caulk makes a more permanent and invisible seal but
may not be appropriate for use against significant historic interior woodwork.
=========================================================
Important Subscriber Information:
The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes).
If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).
|
