Have you ever wondered why so many products come with little packets that say 'Do Not Eat'? The packets contains silica gel beads, which absorb water vapor and keep the product dry, which is an easy way of preventing mold and mildew from taking their toll. Other items would absorb water unevenly (e.g., parts of a wooden musical instrument), causing them to warp. You can use the silica packets or another dessicant to keep special items dry or to keep water from hydrating chemicals. All you need is a hygroscopic (water-absorbing) chemical and a way to seal your container.
Common Desiccant Chemicals
- silica gel (the beads in those little packets)
- sodium hydroxide (sometimes sold as a solid drain cleaner)
- calcium chloride (sold as a solid laundry bleach or a road salt)
This is extremely simple. Just place a small amount of one of the desiccant chemicals into a shallow dish. Enclose an open container of the item or chemical you wish to dehydrate with the container of desiccant. A large plastic bag works well for this purpose, but you could use a jar or any airtight container.
The desiccant will need to be replaced after it has absorbed all of the water that it can hold. Some chemicals will liquefy when this occurs so that you will know they need to be replaced (e.g., sodium hydroxide). Otherwise, you'll just need to switch out the desiccant when it starts to lose its effectiveness.