If you’ve ever experienced failed 3D prints due to brittle filament, excessive stringing, or poor layer adhesion, moisture may be the culprit. Many 3D printing filaments, especially PLA, ABS, PETG, Nylon, and TPU, absorb moisture from the air. This can cause printing defects, clogged nozzles, and weaker final prints.
The good news is that drying filament can restore its print quality. In this guide, we’ll explore the best ways to dry filaments, common signs of moisture in filament, and how to store it properly to prevent future moisture absorption.
Why Do 3D Printer Filaments Absorb Moisture?
Most 3D printing filaments are made from hygroscopic materials, meaning they naturally absorb water from the surrounding air. Some materials, like Nylon and PVA, absorb moisture extremely quickly, while others, like PLA and ABS, take longer but still degrade over time.
When moisture-laden filament is extruded through a hot nozzle, the water turns into steam, creating bubbles and inconsistencies in the print. This leads to issues like:
- Poor layer adhesion
- Stringing and oozing
- Brittle prints
- Clogged nozzles
Drying filament before printing can eliminate these problems and improve print quality significantly.
How to Tell If Filament Needs Drying
Before drying your filament, check for these signs of moisture:
- Popping or hissing sounds when extruding filament
- Excessive stringing between printed sections
- Rough or inconsistent surface finish
- Weaker prints that break easily
- Cloudy or rough filament appearance
If you notice any of these symptoms, it’s time to dry your filament.
Best Methods to Dry Filament
1. Using a Filament Dryer (Best Option)
Filament dryers are specifically designed to remove moisture from 3D printer filaments. They provide consistent heat and airflow, ensuring uniform drying. Some popular filament dryers include:
- eSun eBox Lite
- Sunlu Filament Dryer Box
- PrintDry Pro
How to Use a Filament Dryer:
- Place the filament spool inside the dryer.
- Set the temperature based on the filament type (see table below).
- Dry for 4-6 hours for optimal results.
| Filament Type | Recommended Drying Temperature | Drying Time |
|---|---|---|
| PLA | 40-50°C (104-122°F) | 4-6 hours |
| ABS | 60-70°C (140-158°F) | 4-6 hours |
| PETG | 55-65°C (131-149°F) | 4-6 hours |
| Nylon | 70-80°C (158-176°F) | 6-12 hours |
| TPU | 45-55°C (113-131°F) | 4-6 hours |
2. Using an Oven (Budget-Friendly Option)
If you don’t have a filament dryer, a standard kitchen oven can work. However, be careful, as temperature fluctuations in regular ovens can accidentally melt your filament.
How to Dry Filament in an Oven:
- Preheat the oven to the recommended temperature (use an oven thermometer for accuracy).
- Place the filament spool on an oven-safe surface (avoid direct contact with metal racks).
- Let it dry for the recommended time (refer to the table above).
- Let it cool inside the oven before removing to prevent rapid temperature changes.
3. Using a Food Dehydrator (Great Alternative)
A food dehydrator is another excellent option since it provides consistent low heat over long periods. Most dehydrators allow temperature control, making them safer than an oven.
How to Dry Filament in a Food Dehydrator:
- Place the filament spool inside the dehydrator.
- Set the temperature based on the filament type.
- Let it dry for the recommended time.
Many makers find that dehydrators work just as well as filament dryers and can be repurposed for food when not in use!
4. Using a DIY Heated Chamber
If you enjoy DIY projects, you can build your own heated drying box using a storage container and a heat source (like a small space heater or lightbulb).
Steps to Make a DIY Filament Dryer:
- Take a large, airtight storage container.
- Drill ventilation holes to allow airflow.
- Place a heat source (low-wattage lightbulb or small heater) inside.
- Monitor the temperature and keep it stable.
- Place the filament inside for 6-12 hours.
This method is not as effective as the others but can work in a pinch.
How to Store Filament to Prevent Moisture Absorption
Once you dry your filament, proper storage will prevent moisture from returning. Here are the best ways to store filament:
1. Use Airtight Storage Containers
- Store filament in airtight plastic bins with silica gel packs.
- Vacuum-sealed bags work well for long-term storage.
2. Use Silica Gel Desiccants
- Place silica gel packets inside storage boxes to absorb moisture.
- Recharge silica gel by heating it in an oven at 120°C (248°F) for 2 hours.
3. Use a Dry Box While Printing
- Some printers allow filament to be fed directly from a dry box to keep it moisture-free.
4. Avoid Humid Environments
- Store filament in a cool, dry place away from direct sunlight.
- If you live in a humid area, consider using a dehumidifier in your workspace.
FAQs
1. How often should I dry filament?
If you live in a humid area, dry filament every 2-3 weeks. Otherwise, drying it once every few months is sufficient.
2. Can I print with wet filament?
Technically, yes, but you will get poor results. Moist filament causes stringing, weak layers, and clogged nozzles.
3. Is there a way to tell if filament is completely dry?
After drying, test a small print. If stringing and popping sounds disappear, the filament is dry.
4. Does vacuum sealing prevent moisture?
Yes, vacuum-sealing filament with desiccants helps keep it dry for long periods.
5. Can I dry filament multiple times?
Yes, drying filament multiple times will not damage it, as long as you stay within the recommended temperature.
Conclusion
Keeping your filament dry is crucial for high-quality 3D prints. Using a filament dryer, oven, food dehydrator, or DIY drying chamber are effective ways to remove moisture. Once dried, proper storage with airtight containers, silica gel, and vacuum-sealed bags will prevent further moisture absorption.
By following these steps, you can ensure consistent, strong, and reliable prints every time!