Wet Filament: How to Dry It and Keep It Dry

Popping, hissing, stringing or a rough finish? Your filament may have absorbed moisture from the air. Drying it properly can restore cleaner extrusion, stronger layers and a more consistent surface finish.

How to tell if filament is wet

• Popping or crackling sounds from the nozzle
• Small bubbles or steam coming from the extruded filament
• Unusual stringing, even when your settings were previously working
• A rough, cloudy or inconsistent surface finish
• Weak layers, brittle prints or inconsistent extrusion

Filament can look perfectly normal and still contain moisture. Hygroscopic materials such as PETG, TPU, nylon and polycarbonate absorb moisture faster than PLA, but any open spool can eventually benefit from drying.

Drying filament

Always check the filament and spool manufacturer’s temperature limits first. Drying temperature depends on the material, and excessive heat can soften the filament or deform a plastic spool.

1. Drying filament in an oven

For a basic PLA spool, 50°C for approximately four hours is a useful starting point. Preheat the oven first and confirm the real temperature with a separate thermometer if possible, because many household ovens cycle above and below their displayed setting.

1. Preheat the oven and make sure the temperature is stable.
2. Place the spool in the centre of a clean tray, away from the heating element.
3. Dry it at 50°C for roughly four hours and turn the spool halfway through.
4. Allow it to cool in a dry space, then seal it immediately with silica beads.

Important: 50°C is a general PLA starting point, not a universal setting. Never leave the oven unattended, and do not exceed the heat rating of the filament or spool.

2. Using an enclosed printer and heated bed

An enclosed printer can be used as a warm drying chamber when a dedicated dryer is not available. Place the spool inside the enclosure on a clean, heat-resistant spacer above the heated bed so the plastic spool is not sitting directly against a hot surface. Set the heated bed to 70°C, close the enclosure and leave the filament inside for approximately four to six hours.

• Do not start a print while using the printer for drying.
• Keep the spool clear of belts, wiring and moving parts.
• Turn the spool once during the drying period for more even heating.
• The heated-bed setting is not the same as the enclosure’s air temperature, so drying may take longer than in a proper dryer.

This method works best with a fully enclosed printer that can safely hold a steady temperature. Check the spool regularly and stop if it begins to soften or deform.

3. Using a Creality Space Pi filament dryer

The easiest and most controlled method is a dedicated filament dryer. With the Creality Space Pi, select the type of filament and use the matching preset. The dryer controls the heat for you while allowing moisture to escape. Keep its air vents clear and follow the recommended cycle for the selected material.

A dryer is especially useful for PETG, TPU, nylon and other moisture-sensitive materials. It can also keep the spool warm and dry while you print, reducing the chance of the filament absorbing moisture again during a long job.

Useful starting temperatures

Material	Starting temperature	Approximate time
PLA	45–50°C	4–6 hours
PETG	55–60°C	4–6 hours
TPU	50–55°C	4–6 hours
ABS / ASA	60–70°C	4–6 hours
Nylon / Polycarbonate	70–80°C	6–12 hours

Keeping filament dry

Drying fixes the moisture already inside the filament. Correct storage slows down how quickly it absorbs moisture again.

Best option: vacuum filament bags

Once the spool has cooled, place it in a vacuum filament bag with a small breathable sachet or container of silica beads. Remove the air and seal the bag properly. This is one of the best options for storing individual spools because it takes up very little space and keeps each material separate.

• Use fresh or regenerated silica beads.
• Keep loose beads away from the filament by using a sachet or ventilated holder.
• Check the valve and zip seal before putting the spool away.
• Reseal the bag as soon as possible after printing.

Sealed plastic storage enclosure

For several spools, use a strong plastic storage enclosure with a proper rubber or silicone seal. Add silica beads in a breathable container and, if possible, place a small hygrometer inside so you can monitor the humidity.

This is the desiccant container we recommend and use at DC3D Printers.

• Make sure the enclosure is completely dry before loading it.
• Use enough silica for the size of the container and number of spools.
• Aim to keep the relative humidity below approximately 20%.
• Replace or regenerate the silica when the humidity begins to climb.
• Open the enclosure only when necessary.

Simple rule: dry filament first, let it cool, then seal it with silica. A storage box or vacuum bag keeps dry filament dry, but it will not properly dry a spool that is already wet.

If the same spool still pops, strings or produces a rough finish after drying, repeat the cycle for another hour or two before changing printer settings. This helps prevent moisture problems from being mistaken for a slicer, nozzle or calibration problem.