re-charging desiccant ???

[MIL-DOT]

i've looked,but i can't seem to find any info on the proper temperature and duration for baking silica-gel desiccant packs back to their fully absorbant state. i've read recomendations from 160-180 degrees,to as high as 250.but i'm more concerned with how long it should be left in the oven. any help much appreciated....

 

[.45Guy]

I stick the ones at work in the oven at 103 degrees celcius for 24 hours.

 

[Byron Quick]

I have the ones in the can with the window where you can see the color change so I don't really have to watch time and temperature that closely.

 

[Bruce333]

Found this searching the net:

The most commonly used desiccant is silica gel. This is an amorphous, highly adsorbent form of silica. It is most easily found in a form called "indicating silica gel" which are small white crystals looking much like granulated sugar with small colored specks scattered throughout.

Those specks are how we determine whether the gel is dry or has adsorbed all of the moisture it will hold. If the specks are blue, the gel is dry and capable of carrying out its moisture adsorbing mission. If the specks have turned pink, then the gel has adsorbed all it will and is now saturated. Part of what makes silica gel so useful is that it can be refreshed by driving out the adsorbed moisture so it can be used again. This is a simple as pouring the saturated desiccant into shallow pans and placing in a 250 F oven for no more than five hours until the colored crystals have once again turned blue. You can also do the same thing in a microwave. Stir thoroughly and repeat until dry.

This is for loose silica gel. Some of the silica gel packs may need a lower temp due to the other materials used in the container.

 

[Sheldon J]

The directions on my boys says 150 degrees for 1 hour.

 

[trueblue1776]

Mil spec packs are 250 for 24 hours, we usually went for 4 hours though and they worked well. Those were the older fist-sized ones.

 

[MIL-DOT]

many thanks for the numerous replies. i think i should have elaborated a little more in my original post. i'm using these little tiny packets that my brother just brought me from the music store he works at. they come in guitar cases from the factory. i assume it's OK to toss these in the oven ?

 

[hksw]

As you can see, there are many settings folk use.

The issue is merely to drive out the moisture stored in the silica gels. I've cooked silca canisters in a 350°F oven without any detriment. The key is to just drive out the water. Unless you're using a furnace that's capable of over 500°F, you should be all right with whatever moderate temperature you use.

 

[model 649]

If the packets are made of paper, stay below 451 degrees.
Ray

 

[duck911]

I have one of those paper Remington bags (Rem-Dri) and the directions say 200 degrees for a minimum of 3 hours, or for best results, 200 degrees for 6-10 hours.

--Duck911

 

[hso]

longer=better until all the water is driven out and then it's a waste of power