The Essential Guide to Washing and Curing Resin 3D Prints

Achieving high-quality results in 3D printing, washing, resin curing from resin 3D printing (SLA/DLP) goes beyond just a successful print. The post-processing steps of washing and curing are critical for the final appearance, durability, and safety of your models. Skipping or improperly performing these steps can lead to sticky surfaces, brittle parts, and failed projects. This guide will walk you through the correct process for pristine resin prints.

Why is Wash & Cure So Important?

After a print finishes on an SLA or DLP printer, it's covered in uncured, liquid resin. This uncured resin is sticky, messy, and potentially irritating. Proper 3D printing, washing, resin curing ensures that excess resin is removed and the print is fully hardened, enhancing its mechanical properties and surface finish.

Step 1: Washing Your Resin Print

The first crucial step is to thoroughly wash your print to remove any uncured resin. Most users utilize Isopropyl Alcohol (IPA) or ethanol (90%+ concentration). Always wear gloves and eye protection, and ensure good ventilation.

• Removal: Carefully remove the print from the build plate.
• Initial Wash: Immerse the print in a bath of solvent. Use a dedicated wash station or two containers. Gently agitate or use a soft brush.
• Second Wash: For best results, use a two-stage washing process: first bath for bulk removal, second with fresh solvent for a cleaner finish.
• Ultrasonic Cleaners: For intricate parts, an ultrasonic cleaner with IPA can provide excellent results.

Once washed, inspect the print. It should no longer feel sticky to the touch.

Step 2: Drying the Print

Before curing, your print must be completely dry. Residual alcohol or moisture can interfere with curing, leading to a cloudy or tacky surface.

• Air Dry: Let the print air dry in a well-ventilated area for 15-30 minutes.
• Compressed Air: For faster drying, especially for complex geometries, use compressed air to blow off remaining solvent.

Step 3: Curing the Resin Print

Curing involves exposing the print to UV light to polymerize the remaining resin and harden the model. The exact time depends on the resin type and curing setup.

• UV Curing Station: Dedicated UV curing stations are convenient and effective, often with multiple UV LEDs and a rotating platform for even exposure.
• Sunlight: While free, direct sunlight can be inconsistent and slow. Place prints under direct sunlight, rotating periodically.
• DIY UV Curing: Create a simple setup using UV LED strips or lamps in a reflective enclosure.

Cure your prints until they feel hard and solid, with no remaining tackiness. Consult your resin manufacturer's recommendations to avoid overcuring, which can cause brittleness.

Final Thoughts

Mastering the 3D printing, washing, resin curing process is fundamental for anyone involved in resin 3D printing (SLA/DLP). By following these steps carefully, you will not only improve the aesthetic quality of your prints but also their structural integrity and longevity. Proper post-processing is the key to unlocking the full potential of your resin 3D printer.