Is your filament wet? How to tell and how to fix it
If your prints suddenly started stringing, popping, or coming out rough after weeks of working fine, the filament has probably soaked up water from the air. PETG, TPU and nylon pick up moisture fastest, but even PLA goes bad if it sits out long enough.
Signs your spool is wet
- Crackling or popping sounds from the nozzle while printing
- More stringing than usual, even with settings that used to work
- Rough, bubbly or dull patches on surfaces that should be smooth
- PLA that snaps when you bend it instead of flexing first
- Weak layer bonding, so parts split along the layer lines
How to dry it
A dedicated filament dryer is the easiest fix. It holds a steady low temperature and many let you print straight from the box. Use the drying temperature printed on your spool or the maker's website, since blends differ. As a rough guide, PLA dries at lower temperatures than PETG, and nylon needs the most heat and time. Expect several hours.
A kitchen oven can work in a pinch, but many ovens run hotter than the dial says, and too much heat will soften the filament or warp the spool. Check the real temperature with an oven thermometer first.
Keep it dry
Store spools in an airtight bin or vacuum bag with desiccant packs, and add a cheap hygrometer so you can see the humidity. Recharge or replace the desiccant when the reading starts to climb. If you sell prints, drying before a big batch saves you from reprinting a whole order.