I know that heating wet filament in the oven is the best way to dry it, and that desiccant is typically used to keep filament dry, but will it also eventually dry a spool that has been sitting out in a humid environment? If so, how long would this typically take?
For example, I have a 1kg spool of tightly-wound PLA sitting out at 55% RH for months. If I put it in an airtight container with sufficient desiccant, will it eventually become dried? And how long would it take?
No, it will not. It will help protect it from ambient moisture, but it won’t remove moisture already within the filament, since the filament itself acts as a desiccant.