How Long Can You Leave Resin in a 3D Printer?

3D printing resin is a photopolymer fluid engineered to cure and harden under a source of light. 3D printing resin is an ideal material for expertly designing intricate items and designs using a printer. However, printing resin does have some drawbacks, including the fact that it can expire when left out.

Resin can be left for weeks without issue in a 3D printer. As long as the printing resin is stored in a cool, dry place, away from any UV light, it can keep for weeks. However, if the printing resin is kept in a too warm printer or allowed in sunlight, the resin will only keep for a couple of days.

Keep reading to learn more about 3D printing resin. We will explore the best way to store resin, along with the potential risks involved in using printing resin. We will also cover some tips and tricks to help you take better care of your 3D printer so it can continue to function effectively for a long time.

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Does 3D Printing Resin Go Bad?

3D printing resin can go bad after some time or if improperly stored. The printing resin will cure when exposed to UV rays which in turn will render the resin unusable. As a result, storing your printing reason adequately is essential to prevent it from spoiling.

3D printing resin typically has a shelf life of about one year when properly stored. However, improper storage can spoil printing resin in as little time as an hour or so—store printing resin in a cool, dry place, away from direct sunlight and contamination.

Some manufacturers have developed printing resin with a longer shelf life. These products typically last for up to two or three years when stored correctly. However, the extra shelf life does come with a higher price tag. As a result, it may not be cost-effective to invest in long-lasting printing resin.

Is 3D Printing Resin Safe?

3D printing resin is a valuable material for crafting designs and products with your 3D printer. However, there are some potential risks involved when using printing resin. Depending on what state the resin is in, cured or uncured, it can pose various health risks and hazards to anyone working with them.

Uncured printing resin can cause irritations and reactions if it comes into contact with human skin. Skin contact with uncured printing resin will quickly lead to contact dermatitis, which can cause rashes and hives. In severe cases, this can lead to serious health risks and hospitalizations.

3D printing resin is not always harmful when it comes into contact with the skin. Cured resin is perfectly safe to handle without risking your safety. See below for the features and differences between cured and uncured resin when it comes to usage and safety.

Cured Resin

Cured resin is a resin that has been exposed to UV light and has already hardened and formed. As a result, the harmful chemicals within the plastic are contained within the solid structure. Therefore, the hazardous materials can not escape and irritate your skin.

Uncured Resin

Uncured resin is the resin that you place into your 3D printer for a print. Uncured resin is still in liquid form, so harmful chemicals are not contained within. Therefore wearing protective wear such as gloves when handling uncured resin is strongly advised to prevent reactions from breaking out on your skin.

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Do You Have To Filter Resin After Every Print?

Many people use resin when they are 3D printing. However, not many people are entirely sure of how to care for their printers when using resin. As a result, people often wonder whether there is a need to filter resin after every print or occasionally filter the resin between prints?

You do not have to filter printing resin after every print. However, you will need to filter the resin after unsuccessful prints or other issues during regular operation. Also, if the resin has been sitting in your printer for more than a few days, filtering or hand mixing the resin is a good idea.

If you are stirring your resin manually, ensure that you turn off the printer first. This will prevent any resin from spilling or sloshing out of the printer and onto surfaces or, worse, your skin. Uncured resin is a hazardous material that needs to be handled with respect to safety precautions.

Can You Leave a 3D Printer on Overnight?

3D printing can be a time-consuming affair. Depending on what size nozzle you are using for printing and what materials you use, it could take hours or even days to finish your print. As a result, people are often tempted to leave their printer running overnight, but is this a good idea?

Leaving a 3D printer on overnight is not a good idea. 3D printers should be supervised whenever they’re in operation. 3D printers can catch fire if something goes wrong. You don’t want this to happen when you’re tucked up in bed asleep, as the fire can quickly spread, causing devastation.

You can mitigate the risk of fire when using your 3D printer by installing a metal enclosure around the printer, or you can invest in some compelling fire safety features. Although, even with these added safety features, there is still a real risk of fire that should not be taken lightly.

3D printers should never be left unattended while in operation. This risks a fire starting and quickly spreading throughout your home. Fire will devastate your possessions and indiscriminately eliminate anything in its path.

That said, I know most people in the 3d printing hobby, including myself, leave their printer running overnight and unattended. The printer manufacture will say to not leave the printer unattended because if something goes wrong, they don’t want to take on the risk. It’s honestly more of a judgment call here.

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Final Thoughts

3D printing resin is a unique material engineered to stay in liquid form until exposed to ultraviolet light. Printing resin can remain a liquid in uncured form for up to one year in the right conditions. However, the resin can dry out and harden in as little as a few hours when not correctly stored.

Printing resin is a harmful substance when it’s uncured. Uncured resin that comes into contact with skin will cause severe irritation that can lead to severe issues after prolonged exposure. Therefore, you should wear the necessary protective wear whenever handling uncured resin.

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I'm Rob, the founder of I’m a Marine Corps vet with a master’s degree in Information Systems and have been working in the technology field for over a decade. I started working with 3D printers because I was fascinated by the technology and wanted a hobby that my kids and I can enjoy together.

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