From: kting@cse.unl.edu (Kea Ting)
Subject: Re: Drying silica gel? (Was fungal growth on lenses)
Organization: University of Nebraska - Lincoln
Distribution: usa
Date: Sun, 5 Apr 1992 16:43:35 GMT

ejh2p@faraday.clas.Virginia.EDU (TTHHWWAACCKK!!!) writes:

>In article <HSONG.92Apr4144758@ardour.bellcore.com> hsong@ardour.bellcore.com (G. Hugh Song) writes:

>[stuff deleted]

>>
>>Does anybody know how to dry silica gel to reuse it after a long period 

    Put the silica gel in a aluminium platte then 'fried it on top of the
fired. The main purpose is to make the silica gel dry again. The silica gel
will become blue / purple after you stir fried for about 10 -15 minutes. Depends
on how much do you have in the platte. The color of silica gel is pink ? 
when it is full of moisure or water in it, beware, the silica gel become very 
hot after you 'fried'it. You may want to use a fan to cool the silica gel down,
when it is not as hot, or it is just warm, put it in a air tight cointainer
to cool it down fully, eg a small air tight jam container(This is neccesary 
because I found out that silica gel will absorb moisture in the air very fast
and turn from purple to blue very fast when it contact with the humit air when
 it is hot. By the way this is what happen when I was doing it in my country, I never have a change to do the same here, it is just too dry in USA.) Only put 
silica gel with your camera when the silica gel is fully cold down.

   I have been using silica gel for years. When I was in my country, it is
much humit than here in USA. I bought one pound of silica gel and put the
lenses and camera in a air thight containner and put the whole pound of
silica gel in the container, if I don't open the containner very offen,
 the silica gel can last for 4-5 month. If I open the container very offen to
get the lens and camera, it will last for about 2-3 month before the silica
gel turn pink or very light blue.

                      

           
>>of use?
>>
>>	Hugh
>>
>I would try either putting it in an oven on low heat for a little while
>or try drying it with a hair dryer.


>BTW I heard from an associate in one of the camera stores that I worked
>that it is bad to keep the silica gel after the packaging material for
>the equipment has been opened and unsealed because it absorbs water too quickely and after a very short time just becomes a moisture magnet.  The
>reason, he said that the camera companies are able to use silica gel is
>because the equipment is in sealed containers (ie. the plastic bag
>inside the foam packaging) and there is really not much moisture for the
>silica gel to absorb.  Since I have heard many different opinions and am
>not sure which is right, could someone, anyone please try to enlighten
>me?

     If the condition of air is very humit, you will need a lot of silica gel
in a air thight container with your camera and lenses, make sure the cointainer
is not too big. You may want to put one lens in one cantainer and put some
silica gel (say 1/4 pound or so, or 1/8 pound) in it. Check it frequenly to
see if the silica gel need to be recycle ('fried'), when the silica gel turn
to color other than blue, usualy is pink or light blue, then you know it is
time to 'fried' it)


  soon

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University Of
Nebraska-Lincoln

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Disclaimer : I always speak for my self.
           : Use at your own risk for the method mention above.