# Renewing desiccant packs?



## Arklatex (May 24, 2014)

I got my hands on a few of the large desiccant packs from work. About the size of a deck of cards. They have been exposed to the humidity for a good while before I got them. I've heard in the past that these things can be "recharged" I have seen tutorials on how to do this using ovens, microwave and dehydrators. Have any of yall done this? I would like to put these in some ammo cans if they can be safely recharged. Is there any health concerns regarding doing this since all techniques require the use of things we process food in?


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## Denton (Sep 18, 2012)

Arklatex said:


> I got my hands on a few of the large desiccant packs from work. About the size of a deck of cards. They have been exposed to the humidity for a good while before I got them. I've heard in the past that these things can be "recharged" I have seen tutorials on how to do this using ovens, microwave and dehydrators. Have any of yall done this? I would like to put these in some ammo cans if they can be safely recharged. Is there any health concerns regarding doing this since all techniques require the use of things we process food in?


Yup, you recharge them in the oven. Done it quite a few times.


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## Auntie (Oct 4, 2014)

Denton said:


> Yup, you recharge them in the oven. Done it quite a few times.


Are you going to tell us how you have done it or should we google it and hope that we pick the correct way?


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## Farmboyc (May 9, 2015)

Only health concerns would be if these packs absorbed anything other that water vapor. If they were in a chemical rich environment I would keep them out of the oven. A toaster oven works well. Just set the oven temp above the boiling point of water and it will drive the water vapor put of the silica gel.


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## Mad Trapper (Feb 12, 2014)

Arklatex said:


> I got my hands on a few of the large desiccant packs from work. About the size of a deck of cards. They have been exposed to the humidity for a good while before I got them. I've heard in the past that these things can be "recharged" I have seen tutorials on how to do this using ovens, microwave and dehydrators. Have any of yall done this? I would like to put these in some ammo cans if they can be safely recharged. Is there any health concerns regarding doing this since all techniques require the use of things we process food in?


If it is calcium sulfate it can be regenerated by baking the water off at ca. 425 oF/210 oC.

It is commonly mixed with an indicator, copper (II) sulfate, which is blue when dry and pink when hydrated.

https://secure.drierite.com/catalog3/page19b.cfm

Whoops! Cobalt (II) chloride not copper sulfate is the indicator


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## tinkerhell (Oct 8, 2014)

hadnt thought about it before, but sure! it sounds like a good idea. if the temp of boiling water kills most organisms in water, then it would make sense that the same( or slightly higher) oven temp (once the package is fully saturated with heat) would reset or kill off anything bacteria inside the desiccant bag.


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## Mad Trapper (Feb 12, 2014)

You need to get much higher than bp of water to drive off the water from the hydrate. The indicator will turn blue again when dried.

There are other ways but you need more expensive equipment (vacuum desiccator, high vacuum pump, and secondary desiccant to absorb the water 
(phosphorus pentoxide) ).


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## SOCOM42 (Nov 9, 2012)

There are two types I run into, one made from clay and one from silica jel.
Both can be reused.
If a jell pack, best if you can open one and put contents in in a pyrex measuring cup.
High moisture content will show a dark blue.
When dried the will look almost like light blue tinted ice to clear ice.
Use the open pack as a control item. 
Place all in an oven at 275-325 degrees and watch for color change as stated, remove and seal as soon as possible.
With clay, same temp for one hour to two will do.
Leave the door open a bit to let the moisture escape.
You can make your own from cat litter.


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## paraquack (Mar 1, 2013)

Also thru work I have a few dozen silicone get desiccant packs. I've been drying them in my dehydrator for years. Takes about 8-9 hours for my big ones, 1/2 pound packs. I save up the "dead ones" and do them all at once. Problem is storage of the good ones. Plastic zip lock bags are handy but allow a lot of moisture to get inside that they go bad in six months (I've the ones with the blue color that turns pink when bad). I've started using 2 quart wide mouth mason jars and vacuum them in addition.


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## Mad Trapper (Feb 12, 2014)

I'm thinking you mean silica gel.

Try storing them in 1-gal paint cans and seal the rim with hot wax after closing. You can also dip the mason jars upside down in wax to seal, or just seal them hot and cooling will make it's own vacuum/seal with good lids.


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## tango (Apr 12, 2013)

They can be regenerated by heating in the oven. Directions should be on the packs.
The useable time will be decreased with each regeneration.


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## Denton (Sep 18, 2012)

Auntie said:


> Are you going to tell us how you have done it or should we google it and hope that we pick the correct way?


Sorry, I wandered off for a bit.

I throw them in the oven for an hour or so at about 200 degrees f. "Or so" means I'm not very good at paying attention to time. One time, I fell asleep while making mac and cheese. I woke up to the smokiest house one can have without the house being on fire.

I use the packs that come with large, electronic equipment at work. I dunno if all packs are made the same.


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