The Invisible Enemy
Most thermoplastics are hygroscopic - they absorb moisture from the air. Wet filament is behind a surprising number of print failures: popping sounds, stringing, weak layer bonds and brittle spools that snap. Here's how to spot it and fix it.
Signs Your Filament Is Wet
- Popping or hissing sounds during extrusion
- Rough, bubbly surface finish
- Stringing and oozing between moves
- Brittle filament that snaps when bent
Which Materials Need Drying Most
| Material | Hygroscopic? | Typical Drying |
|---|---|---|
| PLA+ | Moderate | 45-50°C, 4h |
| PETG | High | 65°C, 4-6h |
| ABS / ASA | Moderate | 80°C, 4h |
| Nylon / PA | Very high | 80-90°C, 6-8h |
Drying and Storage
A dedicated filament dryer is the cleanest solution, but a food dehydrator or heated bed with a cover also works. After drying, store spools in sealed bags with desiccant, or a dry box that feeds the printer directly.
Prevention beats curing. Buy quality filament that's properly sealed, and dry it before long or important prints. A little preparation removes the single biggest source of inconsistent results.