Resin in its uncured form is toxic. This is why after you remove models from the print bed, you’ll need to cure it (or technically, “post-cure it”, as it has already undergone curing during the printing process). To cure it after printing, you’ll simply need to expose your models to UV light. Here’s a quick overview of how to do that.
Step 1: Use gloves to remove your 3D printed models off the print bed.
Step 2: Wash your models thoroughly in 100% isopropyl alcohol, or very close to that percentage. You can either use a wash station (typically 2-in-1 with a curing station) or a plastic dish you can close to be airtight.
Step 3: Pat your models dry gently with paper towels so they don’t get sticky.
Step 4: Remove any supports from your models. If your models have any drainage holes, tip them upside down and leave to drain for a few hours before you cure your models.
Step 5: Finally, cure your model under UV light.
Options for UV light exposure:
Your main options include a UV curing station, a UV lamp or nail polish cure station, or most affordable of all – sunlight. Each has pros and cons that I’ll list briefly below.
UV Curing Station
Several brands stock these, and they’re interchangeable. These are highly recommended for convenience and will making curing models quick and easy – between 5 – 10 minutes.
Elegoo Mercury Plus 2 in 1 Washing and Curing Station :
Roughly AUD $150
Can cure models from any printer, but is designed to fit Mars 4 DLP, Mars 3 Pro, Mars 3, Mars 2 Pro, Mars 2.
Elegoo Mercury X Bundle for Large Prints – 2 in 1 Washing and Curing Station :
Roughly AUD $190
Can cure models from any printer, but is designed to fit Saturn 2, Saturn 8K, Saturn S, Saturn, Mars 4 Max, Mars 4 DLP, Mars 3 Pro, Mars 3, Mars 2 Pro, Mars 2.
Sunlight
This is the free option, so no harm starting your journey here. The issue with sunlight is it takes much longer and is less reliable. From clouds muting the intensity of your UV, to general weather and day-to-night patterns limiting the time available for sunlight exposure. The recommended time for UV curing with sunlight is between 1 – 8 hours, depending on the intensity of sunlight available. You should also remember that the entire model requires UV exposure, so you may need to manually turn the model every so often to ensure holistic coverage.
Alternative UV curing lamps
The most popular example of this among the 3D printing community are nail polish cure stations. They’re typically less expensive than brand name 3D printer cure stations, although you should take care to find one large enough for your needs.
UV Light Nail Lamp:
Roughly AUD $37
Make sure to read all safety instructions.
DIY options
While I won’t include a complete guide, there are certainly options for making your own DIY curing station. You will need LED UV lights, a container of a reasonable size, a turntable or battery operated lazy susan, and aluminum foil. The benefit of this is that you can make a much larger UV light station than are commonly sold. The most popular branded official curing stations tend to be rather small in size, meaning you may have a tough time fitting in very large parts or many parts at a time.
UV LED Light:
Roughly AUD $25.99
Again, make sure to read all safety instructions.
How long does resin need to be exposed to UV light before it’s cured?
If you use a UV curing station or other artificial, concentrated source, models can be cured in between 5 – 10 minutes. Personally, I cure my models for at least 3 – 5 minutes on either side.
For clear resin prints, you should only cure the model for about 1 – 2 minutes on either side, as they can become yellowed with overexposure.
In general, try not to overcure your models with unnecessarily long exposure times. This can cause your models to become brittle, especially if they have smaller, thinner areas.
Is UV light exposure dangerous?
Yes, UV light can be harmful. It can cause skin cancer or eye damage at overexposure. Direct exposure when using curing stations or UV lamps should be avoided. The official stations will typically beep if they aren’t closed properly when you try to activate them. If you make your own version, keep all these safety precautions in mind. Don’t stare directly into the light either.
What happens if you don’t cure resin models?
Resin is toxic if it isn’t cured and can put you at risk of health issues or an allergic response.
On top of this, the final cure is part of the firming of the final resin print. If you don’t cure your models, they could become weak, crack, or fall apart over time. Curing is an important step in the 3D printing process that solidifies the resin and makes the print stronger and more durable.
Tips for curing resin models:
- Make sure you wipe the isopropyl alcohol off with a paper towel or leave them to dry before curing your models, or they’ll still be sticky.
- Make sure any models with holes for hollowing or other drainage have had sufficient time to sit so there is no liquid resin still trapped inside. If you cure the model with liquid resin in it, the model can crack and break at a later date. Which is an awful mess, and pretty said if you’ve put painting effort into the model.
