Thread: A question about desicated silica gel

I, like many others here, use packets of desicated silica gel packets to help keep moisture away from my razors. But there has been an annoying thought in the back of my mind. Just how much moisture can each packet absorb? Do they reach a point where they are just there for looks? And if they can only absorb a certain amount of moisture, is there a way to refresh them?

I'd love to hear your thoughts on this.

Yea they only work for so long. I don't know if they can be recharged like putting them in an oven or similar.

Some have colour indicators when recharged in the oven at low temperature for hours the ones i have show pink

ian

works in the microwave too !

Hi Nathan,
Most silica gels are sodium silicate...these often are often blue in color (the gel is blue when dry and pink when hydrated, at which point it has already reached saturation and needs refreshing or replacement).

The best thing to do is to replace these things every couple of months (depending on humidity).

But, to refresh, you heat the silica to 120ºC (250ºF) for 2.5 hrs...this will get the waters off and refresh the gel...but, over time, this effectiveness wears off.

The problem is that most silica gels come in packets and you can't see the color to judge whether this thing is good or not...what I recommend is to have more than two packets in the box (or wherever you keep your stuff from humidity)...open one of the packets and expose the silica (this is to monitor the color)...once this turns pink, change all packets and start with another set of more than two. These things are cheap anyways.

Hope this helps
-Robert

As others said, Silica Gel does reach a point where it simply cannot absorb any more moisture. There are some varieties that change colors. Blue to pink contains Cobalt Chloride which is toxic. There is also Silica Gel that turns from orange to green which is non-toxic. It is safe to reactivate the orange to green, or plain clear Silica Gel in the oven. While it can be reactivated in the microwave, this is not the manufacturer recommended method. Be sure that the packet material can handle being heated in an oven before reactivating any packets. There are sites online that sell the orange to green indicating Silica Gel and provide detailed instructions on reactivating the Silica Gel. SilicaGelPackets.com is one such site.