Summary

This is a very simple, inexpensive and yet effective dry bag for filament.

Instructions

Parts required for the build:

One Ziploc Big Bag Large size
One 50 gram pack of orange indicating desiccant

Tools required

Phillips #0 screw driver

Assembly

Poke holes in the desiccant pack with a Phillips #0 screw driver. I suggest six to eight holes spread evenly over the top of the pack.

Place spools in Ziploc bag and place desiccant pack on top, seal bag. I find over night in a heated place is enough to dry out PLA to be printable again.

When beads in the pack turn green it is time to think about replacing it or refreshing it in the oven.

Amazon link for Ziploc: http://www.amazon.com/gp/product/B003U6A3C6/ref=oh_details_o00_s00_i00
eBay link for desiccant: http://offer.ebay.com/ws/eBayISAPI.dll?BinConfirm&_trksid=p2047675.l1356&rev=4&item=221056467788

Suggested warm place: top of your hot water tank. (if your hot water tank isn't water tight you've got bigger issues than damp PLA)

Update 12/27/2012:

I have now tested this design using an Eva-dry Renewable EDV-300/E-333 Wireless Mini Dehumidifer. This device has a built in dryness indicator so you know when your filament is staying dry and when you need to renew the dehumidifier. The device has a built in drier that allows you to plug it into the wall over night and have it dry itself out. Device is rated to absorb up to a cup of water.

The Ziplock Big Bag and Eva Dry can both be purchased from Amazon.

http://www.amazon.com/Eva-dry-Renewable-E-333-Wireless-Dehumidifer/dp/B000H0XFCS/ref=cm_cmu_up_thanks_hdr

Simple Filament Dry Bag