In article <4ak5je$1su@castle.nando.net>, rmiller@nando.net says...
>hardjono.harjadi@Eng.Sun.COM (Hardjono Harjadi) wrote:
>>Does anybody know where to get silica gel ? Besides opening a bunch
>>of food packages :). How do you know if your silica gel is still
>>potent (not saturated with moisture) ? Can you "recharge" it by
>>putting it in the oven ?
>You can buy silica gel from most florist shops as they use it in drying
>flowers. The disadvantage of this silica gel is it usually is a fine
>powder with will raise hell with cameras. This form needs to be
>contained somehow. You can also buy it from most of the major NY >camera supply houses. This silica gel, which contains an indicator, is >in the form of crystals, usually in a small perforated metal box. When >the crystals turn from blue to pink you know it is time to regenerate. >Regeneration is done in a household oven at a temperature of 200-250F. >Once the crystals turn blue (best to let the stuff cool in a ziplock >bag so it doesn't pick-up moisture) it is ready to go again.

You can also buy indicator silica gel in jars from your local college
chemistry dept. stores (you may need to know someone to get access).
It can be spread out in a large pan for baking, as described above,
or you can heat it in a sauce pan on a stove top (stir continuously),
until it turns blue. If the environment it will be placed in is not
extremely air-tight, check it in a couple of days - it will probably need regeneration (it will take a cycle or two to dry out the local environment even if the enclosure is well sealed, since the gel
cannot hold a vast amount of water).
Hope this helps.