When 3D printing resin, it is important to cure your 3D object so that it fully dries up and hardens. The curing process will make your resin print stronger, stiffer, and less prone to breakage. But how long does resin cure after the printing is completed?
Resin 3D prints generally take one to five minutes to fully cure under high UV light. But the curing time really depends on the size of your print and the curing method you use. Miniatures, for instance, take a minute while average-sized objects take three to five minutes to cure under UV light.
In this article, I will talk about the average curing times for your 3D resin prints according to size, the type of resin you use, and the curing method. I will also talk about what happens to your 3D resin print if it is under-cured and whether there is such a thing as being over-cured. You will also learn how to tell if your 3D object is fully cured.
Average Curing Times of 3D Resin Prints
Cure times for your 3D resin prints are not absolute. There are a few factors that would dictate how much time they will take to fully cure. Ultimately, the duration will depend on the type of resin you are using, the size of the model you are printing, and the curing method.
For example, a certain type of resin will cure within 15 minutes using a UV curing station. The same material could take several hours to cure under sunlight. Then there are high-end wash and cure machines that can cure your 3D object faster than a UV station. The settings for these machines will also affect the duration and the efficiency of the process.
But then again, the size of your print will have to be factored in, too.
Let’s take a standard 1.02-inch (26-mm) and a larger 3.9-inch (100-mm) 3D resin model and see how long 3D prints of these sizes take to cure using different curing methods:
|Curing Method||26mm (1.02 in)||100mm (3.9 in)|
|Elegoo Mercury||2 minutes||7 to 11 minutes|
|Anycubic Wash & Cure||3 minutes||8 to 12 minutes|
|UV Nail Lamp||2 minutes per side||6 to 8 minutes per side|
|Sunlight||2 to 3 hours||10 hours|
Various Factors That Affect Resin Curing Times
Different factors affect the cure times of your 3D resin print differently. These include the surface area of the print, the form or geometry, the UV strength, the temperature level, and the color of the resin.
Opaque or Clear Resin
Opaque resin materials, like gray and black, take more time to cure than clear or transparent ones. This is because UV light can easily penetrate and go through clear materials. And because the colored resin is harder to penetrate, it takes longer to cure.
Surface Area and Form Factor
The bigger the surface area of your 3D resin print, the longer it takes to cure. So miniature or small-sized objects can be expected to cure in only a few minutes because UV wavelength provides coverage of the entire surface quickly.
Meanwhile, 3D parts featuring a complex geometry or form factor also have a longer curing time. UV chambers with rotating plates are recommended for such 3D resin prints because they cure complex forms more evenly and quickly.
Low or High UV Wavelength
Lower UV wavelengths take more time to cure resin than higher UV wavelengths. An example of low UV is UV rays from sunlight, while higher UV includes UV from UV curing stations. Some UV curing stations, however, have small lights while some have larger ones, which consume more power but cure faster.
This means that if you are using direct sunlight to cure your resin, you can expect the post-curing process to be longer. What’s more, the sun’s UV is affected by changing weather conditions, so the UV strength is difficult to determine and is unstable.
Temperature can also affect the curing time. Post-curing takes faster with high heat because it allows the resins polymer network to cross-link. So, as the temperature goes up, the cure time also goes down.
Curing machines or stations have light bulbs in the UV chambers that provide heat, making the curing process faster.
Knowing When Your 3D Resin Print Is Cured
You can tell that your 3D resin print is cured when it is a little less flexible when you wiggle its different parts. And because the cured resin is harder, you can try to drop your print on your table and it will make a more audible thud.
A completely cured 3D resin figure also looks silky or matte. If it still looks wet or glossy, it isn’t fully cured yet.
You can also try to scratch the object with your fingernail. If it doesn’t scratch anymore because it’s very hard, then your 3D object is fully cured.
Here’s a video showing you how to tell your 3D resin print is working:
Is There Such a Thing As Over-Cured and Under-Cured Resin?
Resin can be over-cured and under-cured, although the latter is preferable to the former. Over-curing your 3D resin print happens when UV continues to cure it even after it has hardened enough. Alternatively, taking the 3D resin print prematurely out of the curing machine leads to under-curing.
That means if you leave your 3D resin print inside your UV curing station for a longer time than necessary, your object could become brittle and prone to breakage.
Over-curing can also happen when your 3D print gets extended UV exposure from other UV light sources, such as sunlight, even after you have cured it in a curing station.
Meanwhile, under-curing happens when you have taken your 3D resin object out from the curing machine even before it could fully harden yet. Your object could become tacky.
Curing your 3D resin print doesn’t take a long time. Generally, you just have to wait only a few minutes for your print to cure fully. But the exact number of minutes depends on factors like the size and shape of your print, resin color, curing method, temperature, and other curing machine settings.
It is important to have an estimate of the cure time to make sure your project does not get over-cured and does not become brittle. Meanwhile, if it is under-cured, you can just put it back into the curing machine for a bit more time.
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I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.