Wet filament: how to recognize and dry it safely

Bubbles, popping, rough surfaces or strings can indicate moisture; temperature, retraction or dirt can cause similar symptoms. Before buying a dryer, compare the same spool against a known profile and read the maker’s guidance.

Step-by-step diagnosis

1. Check that the nozzle is clean and use the recommended profile.
2. Save a sample of the defect and record temperature, speed and how long the spool has been open.
3. Check drying time and temperature for that exact brand. Prusa publishes a material table, but its values are not universal for every spool.
4. Check the spool’s heat tolerance and let air circulate as the dryer instructs.

Drying is not curing

A heated dryer works on filament; a UV station works on resin parts. Afterwards, store the spool in a sealed container with desiccant.

Technical source: Prusa drying guidance.