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Can You Leave Resin in Your Printer Overnight?

Resin is messy, and moving it back and forth from the bottle to the printer vat is a hassle. However, what if I told you that you don’t necessarily need to pour out excess resin from your 3D printer?

It’s possible to leave resin in your printer overnight as resin won’t harden when exposed to air. However, it will cure when exposed to light or warmer temperatures. So, it should be kept in a cool, dark place to keep it from hardening or spoiling while it’s in the vat. 

In this article, I’ll tell you how long you can leave resin in your 3D printer and give you some tips for making the resin last longer in the vat. I’ll also tell you how long you can leave your prints on the build plate and talk about the shelf-life of most resins. 

How Long Can Uncured Resin Stay in a 3D Printer Vat?

Pouring more resin into a 3D printer vat is simple. However, removing unused resin from the tank after a print job can be a pain, and it often results in messes. 

So, to solve your pouring problems, you might want to start leaving your resin in your printer between jobs. 

Uncured resin can stay in a 3D printer vat for up to a year as long as you keep it away from sunlight, dust, and heat. Over time, the resin will solidify on the screen, so it’s always best to stir and scrape it before using it again. 

Resin is an incredibly stable material at room temperature, and it needs special conditions to cure. Therefore, if you eliminate the factors that make resin harden, it’ll stay in liquid form for quite a while.

Some 3D printing experts have seen success printing with resin left in the printer for a whole year. Meanwhile, I’ve reused resin at the three-month mark, and my prints came out perfectly, so I don’t doubt that it can last that long. 

Manufacturers Recommend Two Months

Most resin manufacturers and printers recommend that you don’t use a resin that’s been sitting in the vat for more than two months since it might congeal and get stuck to the screen. 

With that in mind, if you’re worried about damaging the screen, always be sure to check the consistency of your resin and remove any stuck-on materials before printing.

It Needs To Be Kept in the Right Environment

Resin will only stay viable in your printer if you store it correctly. 

So, if you expose it to UV light or warmer temperatures, it’ll start to clump up or film over. In addition, since it’s a liquid, resin is prone to collecting dust and debris, which could ruin a 3D print. 

So, your resin will last quite a while in the vat, but only if you prevent curing. For the best results, keep it cool, dark, and clean. 

To see how month-old resin prints, check out this video experiment from Kersey Fabrications, who tested how long his resin could sit in the 3D printer vat: 

How To Make Resin Last in Your 3D Printer Vat

If you want to leave resin in your 3D printer, you might want to take some extra measures to ward off the curing process. 

Here are some things you should do if you want to make your resin last longer in your 3D printer vat:

  • Always check for resin leaks underneath your vat before printing to ensure that you don’t damage your 3D printer. 
  • Store your 3D printer somewhere dark – cover any windows in the room and keep the lights off when you aren’t printing.
  • Keep your printer in a cool spot away from vents and drafts.
  • Cover the vat and uncured resin with a silicone mat or vat cover, and use your printer cover or a drop cloth to block out light and dust.
  • Scrape and stir your resin with a spatula or silicone brush before and after every print to remove clumps and cured spots. 
  • Clean your resin vat regularly. 
  • Filter out resin if you find clumps, debris, or cured resin pieces in your vat. 
  • Top off your vat before every print to avoid running out of resin. 

To learn more about the best way to clean out a resin 3D printer, check out this simple walkthrough from FacilityD20 in this YouTube video: 

How Long Does 3D Printing Resin Last? 

3D printing resin lasts between one and two years before expiring. But it’ll only last that long if you keep it sealed in a dark, cool place. In addition, you may be able to use resin after expiry, but it’ll take longer to cure when it’s older. 

3D printing resins, as I have already mentioned, are sensitive to light. That’s because they contain photo-receptors that make the resin cure when your printer shines a bright light on them. 

These photo-receptors only stay receptive for so long, and over time, they may evaporate. If that happens, your resin won’t cure as you print, leaving you with a gummy, gloopy mess every time you try to make something. 

So, be sure to monitor the specified expiration date on your 3D printing resin and be prepared for potential print failures once it reaches the end of its life. 

How Long Can You Leave a Resin Print on the Build Plate?

Sometimes, things happen, and you need to leave your 3D print on your printer before you can cure it. Whether something came up or you ran out of curing materials, waiting a while to finish things shouldn’t be a problem as long as you keep your printer somewhere dark. 

Resin print can be left on the build plate for months without any adverse side effects as long as you keep it away from light. If you keep it from curing, it should be easy to remove from the build plate when you’re ready for post-processing. 

So, you can leave your 3D prints on the build plate as long you keep your printer in a dark, cool location. 

It’s crucial to avoid exposing prints to the sun while still attached to the printer since curing will harden the object. Also, as your resin object sets, it may become more challenging to remove, and you might not be able to snap off supports or finish it efficiently. 

However, your print won’t cure if you keep it in the dark, allowing you to put off post-processing as long as you want to. 

Final Thoughts

You can leave resin in your 3D printer overnight, and you might even be able to get away with leaving it in the vat for up to a year. 

Still, you’ll have to prevent curing to make it last that long. That’s why it’s crucial to store resin 3D printers and resin in cool, dark spaces. 

In addition, stirring, scraping, and cleaning your vat can help make old resin work like new. Be sure to keep everything clean and remove cured particles before printing to avoid failure.