ASA (Acrylonitrile Styrene Acrylate) has become one of the top materials for outdoor and industrial 3D printing thanks to its UV resistance, weatherproof strength, and durability. But there’s one major debate in the maker community — can you actually print ASA without an enclosure? The short answer is yes, but it takes some finesse. In this article, we’ll break down everything you need to know to make it work — from print settings and environment control to real test results.
Why Print with ASA Filament?
ASA filament is loved for its toughness and weather resistance. It’s perfect for prints that live outdoors — such as drone parts, automotive components, or garden fixtures — where PLA would deform and PETG might yellow over time. It’s also more resistant to UV light than ABS, making it ideal for prototypes and products exposed to the sun.
The Common Belief: “Enclosure Required”
Most guides claim ASA printing demands a heated chamber to prevent warping and layer separation. While that’s true in many cases, it’s not impossible to achieve stable prints without one. With careful setup and the right temperature management, you can still get strong, high-quality results in an open printer.
So, Is It Possible to Print ASA Without an Enclosure?
Absolutely — if you understand the filament’s sensitivity to temperature fluctuations. The trick lies in optimizing your print settings, managing airflow, and stabilizing the environment around your printer.
Understanding ASA Filament and the Challenges
What Is ASA (Acrylonitrile Styrene Acrylate)?
ASA is a thermoplastic similar to ABS but with better weather and UV resistance. It’s durable, impact-resistant, and capable of maintaining color outdoors for years. Unlike ABS, it emits slightly fewer fumes but still requires proper ventilation.
Why ASA Typically Demands an Enclosure
ASA shrinks significantly as it cools. Without consistent heat, this leads to warping or layer splitting. Enclosures help maintain temperature stability — but you can simulate that effect through smart environmental control.
How ASA Behaves Without an Enclosure
When printed in an open environment, ASA cools too quickly, especially on tall prints. This rapid cooling is the primary cause of cracks. By controlling room temperature and reducing direct airflow, you can slow down the cooling just enough to maintain layer adhesion.
Printer & Environment Setup Without an Enclosure
Heated Bed and Build Surface Requirements
A heated bed is mandatory for ASA. Set it between 100–110°C and ensure even heat distribution. Using a PEI sheet or glass bed with an adhesive like Magigoo or glue stick helps the print stay firm. Adding a brim or raft further improves adhesion and minimizes edge lifting.
Ambient Conditions: Controlling Drafts and Temperature
Even slight drafts can ruin ASA prints. Avoid fans, air conditioners, or open windows. Keep the ambient room temperature between 25–30°C if possible. Some makers even place a cardboard or acrylic barrier around the printer to mimic partial enclosure behavior.
Choosing a Suitable Printer and Hardware Configuration
While any open-frame printer can work, a direct-drive extruder provides better control. The ideal nozzle temperature ranges from 240–260°C. Use minimal part cooling (0–10%) since too much airflow hardens layers too quickly.
Print Settings & Filament Handling
Recommended Settings for ASA Without Enclosure
- Nozzle Temperature: 250°C (±10°C depending on brand)
- Bed Temperature: 105°C
- Print Speed: 40–60 mm/s
- Cooling Fan: 0–10%
- Infill Density: 20–40% for structural parts
- Brim: 5–10 mm for better bed adhesion
Filament Drying and Storage
ASA absorbs moisture easily, which leads to stringing and weak adhesion. Always dry it before printing — 70°C for 4–6 hours is ideal. Store spools in airtight containers with silica gel when not in use.
Adhesion Techniques and First Layer Optimization
Getting the first layer perfect is critical. Level your bed carefully and lower the initial layer speed. Use adhesive aids like glue stick, Magigoo, or Kapton tape. Increasing the first-layer height to 0.25 mm can help with initial sticking.
Common Issues & How to Mitigate Them
Warping and Lifting Edges
To fight warping, increase the brim size or use a draft shield. Keeping the bed hot throughout the print and letting the model cool gradually also helps prevent sudden shrinkage.
Layer Separation or Delamination
If layers are splitting, increase nozzle temperature slightly and slow down your cooling fan. You can also raise the ambient temperature by blocking airflow.
Surface Finish Imperfections
Stringing or blobs usually come from moisture or incorrect retraction. Dry the filament and fine-tune your retraction distance. Lowering the temperature slightly can reduce oozing.
Practical Tips for Success: Real-World Case Study
My Test Print: ASA on an Open Printer
I tested an ASA filament print on an open Prusa-style printer with a 250°C nozzle and 105°C bed temperature. The room temperature stayed around 28°C, and cooling fans were disabled. The model — a car mirror mount — printed in 4 hours with only minor corner lifting.
What Worked Well and Why
Adding a 10 mm brim, preheating the bed for 10 minutes, and using glue stick significantly improved adhesion. A small cardboard barrier reduced drafts, keeping the temperature stable enough for smooth layer fusion.
When You Should Still Consider an Enclosure
Large or tall prints will always benefit from an enclosure. If your environment is cold or drafty, an enclosure ensures consistent results and reduces stress-related cracking.
Post-Processing and Finishing ASA Prints
Cleaning Up the Print
Remove brims and supports while the print is still slightly warm to prevent cracking. ASA sands smoothly and can be polished for a glossy surface.
Finishing Techniques
ASA accepts paint well — use acrylic-based coatings for color and UV protection. You can also vapor-smooth it using acetone, similar to ABS, for a glossy finish.
Practical Use Cases
ASA’s resistance makes it excellent for outdoor gadgets, RC vehicles, and eco-garden accessories. It’s a professional material suited for functional parts that endure real-world wear.
Summary & Key Takeaways
Printing ASA without an enclosure is absolutely possible if you respect the material’s thermal behavior. Keep your setup stable, avoid drafts, dry your filament, and minimize cooling. With the right balance of heat and patience, you can achieve durable, weather-resistant parts even on an open-frame 3D printer.
Quick Checklist Before You Print:
- Heated bed at 100–110°C
- Nozzle between 245–260°C
- Fan at 0–10%
- No drafts or cold air nearby
- Dry filament before use
Master these fundamentals, and you’ll unlock ASA’s full potential — no enclosure required.