Feb 6, 2019

SLA Post-Processing – The Best Ways to Clean Resin 3D Prints

Post-processing is critical for achieving the full resolution of your SLA 3D printer. Here are the best ways to go about cleaning up your SLA prints.

SLA Post-Processing Why It's Important

Post-processing lets you take full advantage of your SLA printer and resin. Source: Formlabs

Post-processing lets you take full advantage of your SLA printer and resin. Following the correct process will maximize the quality and mechanical performance of your prints. Stumbling blind, however, can make it difficult or even disastrous.

Here, we’ll walk you through the necessary steps and the various methods for approaching each.

SLA Post-Processing Safety Precautions

Safety precautions are necessary for handling SLA resins. Source: Formlabs

Before we get started, make sure that you understand the safety precautions involved with handling SLA resins. These resins are toxic, and direct contact with skin should be avoided. Spills can also get messy, so make sure that you have a clear work area.

What you’ll need:

  • Nitrile gloves
  • Safety glasses
  • A clear workspace

If resin accidentally comes in contact with bare skin, wash immediately with soap and water. Avoid leaving resin trails on items you touch. If a spill occurs, clean right away before the resin hardens. 

With that out of the way, let’s get started with post-processing!

SLA Post-Processing Step #1: Rinse Off the Part

Rinse your print to remove uncured resin. Source: Formlabs

When your part comes out of the printer it is covered with uncured resin. You’ll have to rinse it off before going further with post-processing.

Method #1: Ultrasonic Bath

Using an ultrasonic bath, like one for cleaning jewelry, is a simple and effective way of cleaning SLA prints. Fill the bath with enough isopropyl alcohol (IPA) to cover your print and let it sit for a couple of minutes. This will take off the fine layer of uncured resin stuck to your model, leaving behind a smooth, clean finish. 

Method #2: Dunk and Rinse

If you don’t have an ultrasonic bath, simply dunking your part into a tub of IPA works as well. Move your part around and rinse it well to get the resin off. This method is simple and quick, but will not achieve as thorough a clean as the ultrasonic bath. Two rinses or more may be necessary to strip off the resin clinging to the surface. 

SLA Post-Processing Step #2: Remove Supports

Supports can be removed with flush cutters. Source: Formlabs

Next, remove the tree-like support structures attached to your model. This can be done before or after curing, but doing it before will be easier. Always watch out for stray bits of plastic that go flying. 

Method #1: Break Them Off

If you’re not worried about small details, breaking the supports off by hand is the quickest way to go. If your model has fine features, however, it’s best to use more caution. 

Method #2: Use Flush Cutters

For more intricate parts, use flush cutters to carefully snip off the supports. Get as close to the model as possible without marring the surface.

With both methods, small nubs will be left on your print. This is inevitable but easily remedied with a little sandpaper and some patience. 

SLA Post-Processing Step #3: Cure the Print

Curing your print locks in material properties. Source: Formlabs

The last step in post-processing is to UV-cure your print. This is necessary for many functional resins because it finalizes the material properties of the model. 

Method #1: Curing Station

Many SLA printer manufacturers also sell curing stations. These are specifically optimized for their resins, allowing for finely tuned curing times. This is useful for larger prints and professional environments. 

Method #2: Nail Polish Curing Lamp

This is an inexpensive and accessible method of quickly curing your model. Simply place it under a nail polish lamp and let it sit overnight. Adding a turntable can help get a more even exposure.

Method #3: DIY Curing Chamber

Many hobbyists will build their own, inexpensive curing chambers, makeshift versions of commercial curing stations. This is easily done by placing a UV light in a box lined with aluminum foil. Place the model on a solar or battery powered turntable to get an even exposure. 

Method #3: Solar Power

To go fully green, use good-old solar power. Place your part outside on a sunny day, and you’ll have a nice, even, UV light. The main drawback of this approach is the extra patience required. You’ll have to sit back and let the sun do the work. 

SLA Post-Processing You're Golden!

Post-processing will get you the best print quality and material properties. Source: Formlabs

With these 3 easy steps, your SLA print is post-processed and ready to go! From here, you can put it straight to use or prime and paint it as you wish.

Continue perfecting your 3D printing skills with our guides on UV resin 3D printersSLA, and SLA quick tips

Happy printing!

License: The text of "SLA Post-Processing – The Best Ways to Clean Resin 3D Prints" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.

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