Home/How to Dry Filament

How to dry filament.

Bad prints often have nothing to do with your slicer settings. The filament is wet. Moisture turns to steam in the nozzle and ruins the surface, the layer bonds, and the stringing. Dry the filament and those problems disappear. Here is how to tell if yours is wet and how to fix it.

DIAGNOSIS · 5 SIGNS

Your filament is wet. Here is how to tell.

Popping or cracking from the nozzle

Small water pockets vaporize as they hit the hot end. You can hear it: a faint crackling or popping while printing. This is the clearest sign of wet filament.

Rough, bubbly, or fuzzy surface texture

Steam escaping through the extruded bead creates small bubbles and a rough surface. Prints that used to come out smooth suddenly look textured or pebbled.

More stringing than usual

Wet filament strings badly even on settings that worked last week. If your stringing got worse without changing anything, moisture is likely the cause.

Weak, brittle layer adhesion

Layers delaminate under light force. Wet filament does not fuse as well between layers, so the print snaps along layer lines instead of through the material.

White wisps of steam from the nozzle

Visible steam or white smoke coming off the nozzle during printing is a definitive sign. The filament is boiling water as it extrudes.

ABSORPTION RATES

Know which filaments go bad fastest.

Fastest to slowest. Listed from most to least moisture-sensitive.

MaterialSpeedDetail

NylonHours

Absorbs moisture from open air in 1 to 2 hours in humid conditions. Must be printed dry and stored sealed.

TPUHours to 1 day

Nearly as fast as Nylon. Store sealed with desiccant between uses.

PETGDays

Absorbs moisture within a few days in normal room humidity. Dry before any print run if the spool has been open more than a week.

PLA+Days to 1 week

Absorbs faster than standard PLA. Additives that improve flexibility also attract moisture.

ABS / ASAMany days

Moderate absorption rate. Usually fine for a few weeks in normal conditions.

Standard PLAWeeks

The most moisture-resistant common filament. Low risk for short-term storage in normal humidity.

METHODS · RANKED BY SAFETY

The three ways to dry filament.

Best

01. Dedicated filament dryer ($30-60)

The easiest option. Set it and leave it. SUNLU, Sovol, and eSUN all make good ones. You can print directly from the dryer while it runs. No need to wait.

MaterialTempTime

PLA45-50°C4-8 hours

PETG / ABS / ASA65°C4-8 hours

Nylon70-80°C12+ hours

TPU45-55°C4-6 hours

02. Food dehydrator

Works well if the dehydrator reaches high enough temps. Many units max at 70°C. Fine for most materials. The key check: measure if a standard 1kg spool fits inside before buying. Some smaller dehydrators cannot fit a full spool without removing a shelf tray. Run at the same temps listed above. 4 to 6 hours is usually enough for PLA, PETG, and ABS. Nylon needs more time.

Use Caution

03. Household oven

This works but requires care. Most ovens do not hold temperature accurately below 100°C. The actual temp can swing 10 to 15°C above or below the dial setting. PLA will soften and warp if the oven runs hot (PLA deforms at 60°C).

If using an oven: verify temperature with a separate digital oven thermometer before putting filament in. Crack the door slightly for airflow. Not recommended unless you have confirmed temperature accuracy. For Nylon and TPU, use a dedicated dryer instead.

STORAGE

Keep it dry between prints.

Drying fixes the problem, but only until the spool absorbs moisture again. Proper storage keeps filament dry between uses.

Airtight bag or container with silica gel desiccant packets. This is the minimum for Nylon and TPU.

Vacuum storage bags remove air entirely. Best option for long-term Nylon and TPU storage.

Desiccant packs recharge in an oven at 120°C for 1 hour. Reuse them indefinitely.

Log the date you opened each spool. After 2 to 3 weeks in humid air, PETG and TPU likely need drying again.

FREE APP

Log open dates and dry dates. Never print wet filament.

You opened a PETG spool two weeks ago. Is it still dry? You will not know unless you logged the date. Log your open date and last dry date per spool in PrintLog3D. Before your next print session, check the app. If it has been more than a week in humid air, dry it first. Clean prints start before you hit print.

Get the Free App