-----Original Message-----About two years ago, there was a discussion in this list about the tropical cabinet. Several months after that, it resulted in the construction of such a cabinet in the house of my friend, Dietrich Kleinschmidt.
From: owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx [mailto:owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Elson T. Elizaga
Sent: Friday, April 09, 2004 8:40 PM
To: List for Photo/Imaging Educators - Professionals - Students
Subject: Torpical cabinet and cobalt chloride in silica gelDietrich followed almost all the details I gave him. One particular change was interesting. Instead of using two 30-watt bulbs, he used two 25 watts. The result is a shortage in relative humidity level, by about two percent. This condition, however, seems to still prevent the growth of molds, as Dietrich remains quite satisfied by his box.
See http://nazca.sni.ph/tropical_cabinet
On a related topic, I just got information from a chemist that the blue thing in silica -- the silica that we use for our photographic equipment -- is cobalt chloride which, he claims, is highly toxic. It allegedly transfers to the skin during contact, and then to food, and then inside the body, where it accumulates. Here's a portion of his post yesterday in another list:
BUT cobalt chloride (which is the indicator compound found in silica gel) is highly toxic. the LD-50 of cobalt chloride in rats is 770 mg/kg, compare that with malathion with an LD-50 of 1375 mg/kg orally. of course, comparison like this is meaningless, but just to give you an idea. cobalt in pottery and earthenwares are most probably fused, cobalt chloride in silica gel is just mixed in. if you put the indicating silica gel in water, cobalt chloride will dissolve, and you'll get a very light pink color.Any comments from other chemists in the house?cobalt in silica is not dust. you're right. but it's also not fused. and it is soluble in water (or the sweat of you hands). and that's how you get the cobalt into your system (if you touch the silica gel with your bare hands, hint hint...use gloves :).
Elson
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Nazca Graphic Design & Photography
http://nazca.sni.phKindelen Enterprises
http://nazca.sni.ph/kindelen
Elson;
That cabinet sounds
like a good idea, although I would be worried about fire if you had poor air
circulation and the lights stayed on all the time. I have spent a few
years in Korea and use to place oily rags in a box (preferably metal) along with
what we wanted to protect. Often weapons. Price sounds
right.
John
