I was sitting beside my 3D printer wondering just how long you can leave resin in the 3D printer vat for without issues. It is something that I’m sure many people have also wondered, so I decided to write an article about it to share the answer.
You can leave uncured resin in your 3D printer vat/tank for several weeks if you keep it in a cool, dark area. Giving your 3D printer extra can prolong how long you can leave uncured resin in the vat for, though when it comes time to 3D print, you should gently stir the resin, so it is fluid.
That is the basic answer, but there is more interesting information to know for the full answer. Keep reading to brush up on your knowledge of uncured resin being left in your 3D printer vat.
Can I Leave Resin in the 3D Printer Tank Between Prints?
You can leave resin in your 3D printer’s tank or vat between prints and things should be just fine. It’s a good idea to use the plastic scraper that comes with your resin 3D printer to move the resin around and detach any hardened resin before printing another model.
When I print with my Anycubic Photon Mono X, a lot of times after a 3D print, there will be remnants of cured resin in the vat that should be wiped off. If you try to print another model without cleaning, it can easily get in the way of the build plate.
In the early days of resin printing, I’ve had a few prints fail due to not properly clearing up the bits of resin between prints.
Something that people advise is to actually layer your FEP film with a silicone PTFE spray or liquid, then let it dry off. It does a good job with preventing hardened resin from sticking on the FEP film, and more so on the actual build plate.
The DuPont Teflon Silicone Lubricant from Amazon is a light, low-odor spray that should work well for you and your 3D printer. You can also use it for squeaky door hinges, on machines around the house, to clean grease, and even on your vehicle.
One user used this versatile product to grease up their bike and their rides feel much smoother than before.
How Long Can I Leave Uncured Resin in the Printer Vat Between Prints?
In a controlled, cool, dark room, you can leave uncured resin in your 3D printer vat for several months without issues. It’s a good idea to cover your whole resin printer to block any light from affecting the photopolymer resin inside the vat. You can also 3D print a vat cover.
Many people regularly go weeks with leaving uncured resin in the printer tray, and they don’t run into any problems. I’d recommend doing this only if you have enough experience and have got the process dialed in.
It really depends on whether you have your resin printer in a room that gets a lot of sunlight, or gets pretty hot. In such an environment, you can expect the resin to be affected, and require proper storage back in the container.
Keeping your resin 3D printer in a cool basement will have the resin lasting much longer than keeping it in a warm office with a lot of sunlight coming through.
The specialized UV cover does do a great job in protecting the resin, but over time, the UV light can start to pierce through. It’s not much of an issue if this happens though, as you can just mix the resin by using your plastic spatula.
Some people just push the hardened resin to the side and start a print, while others will filter out the resin back into the bottle, clean everything out, then refill the resin vat.
It really is up to you, but if you are a beginner, I’d recommend using the proper process of cleaning everything out properly, to increase your chances for a successful print.
How Long Does 3D Printer Resin Last?
3D printer resin tends to have a shelf life of 365 days, or one full year according to Anycubic and Elegoo resin brands. It’s still possible to 3D print with resin past this date, but its efficacy won’t be as good as when you first purchased it. Keep the resin in a cool, dark area to prolong it.
Resin is designed to be kept on shelves for most of its use, but if you don’t pay attention to different factors, the life span can be reduced significantly. There’s a reason resin is kept in bottles that block UV light, so keep the bottle away from light.
Sealed resin stored away in a cool cabinet is most likely going to last longer than unsealed resin put on the window seal.
The life span of resin both in an opened or an unopened condition depends on the conditions in which they are sitting.
The resin should be kept in the bottle with the cap on it, and it can last for months. Make sure to swirl your bottle of resin before using pouring it into your 3D printer vat as the pigments can drop to the bottom.
What Can I Do With Leftover Resin From My 3D Printer?
You can simply leave leftover resin in the tank, but ensure that it is properly protected from UV light. If you are going to start another print within a few days, then you can keep it in the 3D printer, but if not, I’d advise filtering the uncured resin back into the bottle.
With the fragments of semi-cured resin, you can remove them onto a paper towel, then cure it with UV light as you would with your normal resin 3D prints. Make sure not to touch the resin as usual, though once it’s fully cured, it’s safe to dispose of as normal.
Curing with a strong enough UV light should only take a few minutes, but since a lot of the resin might not be washed off as usual, I’d cure it for longer just in case.
If you want to dispose of your gloves, empty resin bottles, plastic sheets, paper towels, or any other objects, you should do the same procedure with them as well.
Leftover resin that has mixed with your liquid cleaner such as isopropyl alcohol has to be specially disposed of, usually by putting it in a container, and taking it to your local recycling plant.
Most places should take your leftover mix of resin and isopropyl alcohol, although sometimes you need to go to a specific recycling plant for them to take care of it.
Can You Reuse 3D Printer Resin?
You can reuse uncured resin just fine, but you’ll need to filter it out properly to ensure the larger pigments of cured resin aren’t put back into the bottle. If you do this, you might be pouring back hardened resin back into the vat, which isn’t good for future prints.
Once resin is slightly cured, you can’t practically reuse it for your 3D printer.
What Should You Do With Cured Resin Supports?
There isn’t much you can practically do with your cured resin supports. You can get creative and use it for some kind of art project, or you can blend it up and use it as a filling for models with holes in them.
Simply making sure your resin supports are fully cured then disposing of them is the usual practice.
How Long Can A Resin Print Stay on the Build Plate?
Resin prints can stay on the build plate for weeks to months without many negative consequences. You just simply wash and cure your resin prints as normal after you choose to take it off the build plate. I’ve left a resin print on the build plate for 2 months and it still came out great.
In terms of how long you can wait to cure resin prints, you can wait several weeks if you wanted because the UV light cover should stop it from curing from light exposure.
Do keep in mind that over time, air can slightly cure prints over time, though you want to ensure resin prints are washed before they cure.
You can definitely leave resin prints on the build plate overnight and they should be just fine.
Michael Dwamena is the founder of 3D Printerly, a platform dedicated to simplifying 3D printing for hobbyists and professionals alike. Owns over 20 3D printers (filament and resin) and has plenty experience 3D printing. Michael has authored over 900 articles, helping millions navigate the exciting world of 3D printing.
Reading Time: 7 minutes 
