The variety of resin products available for crafting is extensive. However, UV resin and epoxy stand out in popularity among DIY crafters thanks to their attractive enamel-like appearance.
Now, it is not uncommon to see beginners use the two resins interchangeably. Nonetheless, the assumption that they work the same due to the similarity in appearance often leads to failed projects.
Therefore, what’s the difference between UV resin and epoxy? The difference between UV resin and epoxy is that the former is UV light activated while the latter only requires a hardener to cure. UV resin hardens faster than epoxy but is less durable.
This, among other distinct properties, makes one a better fit for specific projects than the other. So if you are just starting out with resin and feel ill-equipped to make a choice, read on.
In this post, we’ll define, compare, and contrast UV resin vs. epoxy. We’ll also tell you what each one is ideal for to help you choose the right one for your crafts. Let’s get started!
What Is UV Resin?
UV resin is one of the various synthetic resins made industrially through polymerization. This resin requires energy radiation from UV light to cure, and that is how it acquired the name UV resin.
The ultraviolet light can be sourced from a lamp, flashlight, or naturally from the sun. Once brought directly under this light, UV resin will begin to harden almost immediately through a photochemical process.
It is this very property that makes UV resin popular —the short duration it takes to cure. You might even come across other crafters that call it the resin for the impatient.
UV resin is also a one-part resin. It does not require any special mixing or preparation and is ready to cast right out of the bottle. And because it will only start to thicken when UV light is introduced, the working time window is pretty flexible. You can take your time pouring and embedding things, as the resin stays wet throughout.
Despite being easy to use, it is not always rosy when working with UV resin. You may still encounter challenges, a common one being the resin failing to harden even after exposing it to UV light for quite some time. There are a couple of reasons for this, but the most probable cause is insufficient light intensity. UV resin requires high temperatures to cure properly.
Therefore, when selecting a UV device, ensure that it emits long wavelengths. Long wavelengths penetrate deep into the resin compared to short wavelengths that only warm it superficially.
Other times, non-curing has nothing to do with the quality of the light but rather blockages that hinder deep penetration. The UV light may be blocked by opaque molds, pigments, too much glitter, etc.
Lastly, you may have cast the UV resin too thick. 3mm is the maximum thickness for applying UV resin. 4mm if you push your luck. Anything thicker than that is bound to encounter problems curing. So if you must go big, ensure you build up the thickness in thin layers, giving ample curing time in between them.
Once hardened, UV resin has a beautiful pristine clarity that is unfortunately not long-lasting. UV resin is easily marred by high heat or scuffing. The resin has a limited 6 months shelf life as well. Consequently, it is packaged only in small bottles to avoid wastage.
The downside of purchasing small bottles is that it gets expensive quickly if you need large volumes of the resin. There’s also the cost of the UV light device to consider too, which makes UV resin a bit costly.
What Is Epoxy?
Epoxy like UV, casting, and polyurethane resin is a synthetic resin. It is industrially formulated using chemical polymers. The key feature of epoxy is that it is a 2-part resin. What this means is that the epoxy requires a hardener mixed into it to trigger the curing process.
When buying this resin, it will always be packaged in two separate bottles. One part is the epoxy, and the other one is the hardener. Accuracy in measurements is fundamental for the optimal reaction of the resin and hardener. The two parts must be equal and blended thoroughly; otherwise, the resin will not harden.
In addition to precise measurements, you also need to work reasonably fast because the work time here is not as flexible as with UV resin. Once the hardener and resin are combined, the mixture starts to thicken.
The reaction also produces bubbles from trapped air. These have to be removed using heat for a flawless appearance.
As you can see, epoxy requires more hard work and skill than UV resin to pull off successfully. Furthermore, you must exercise patience during the entire process as curing can take anywhere from 2-4 days.
That’s a painfully long wait, but on the flip side, the results are fantastic if cured correctly. The epoxy resin hardens into a high-gloss, crystal-clear, rock-solid mass. It is also heat and scratch resistant and extremely durable.
Epoxy resin can be found in a range of quantities from a few oz to gallons. That’s because it has a much longer shelf life of 3 years. Once the seal is broken, any leftover is good to use for another 6 months.
Another reason it is available in large quantities is that epoxy can be cast thicker than UV resin. A single layer of up to 5cm is allowed, making sense to package larger volumes of it.
So Which Is Better, UV Resin Or Epoxy?
Since each resin has its unique characteristics, it’s not possible to pinpoint the better one. The greatest strength of UV resin, for example, is in its quick processing time, while epoxy is the more durable alternative.
Therefore, the better resin here depends on the crafter’s priorities and needs. For a quick comparison, here are aspects of UV resin vs. epoxy resin side by side.
| Product | UV Resin | Epoxy |
|---|---|---|
| Preparation | Ready to pour, no preparation needed | Resin and hardener must be measured in equal parts and mixed thoroughly |
| Curing conditions | Cures in high temperatures and MUST be aided by UV light | Cures at room temperature, UV light is unnecessary |
| Curing Time | Hardens in 2-5 minutes | Takes 24-72 hours to cure completely |
| Max Thickness | 3-4mm | 50mm (5cm) |
| Durability | Low durability, can be damaged by high heat and scratches easily too | Highly durable and is unaffected by heat and also resistant to scuffing |
| Cost | Costly by volume and additional UV torch/lamp expenses | Cheaper by volume |
From the information laid out above, you can quickly gather the areas where one resin overpowers the other.
When To Use UV Resin
UV resin will be ideal to use if you are a beginner, time-crunched, or simply want quick results. It offers a hassle-free experience where you just pour the resin into a mold or other surface straight from the bottle.
This saves you so much time you would have otherwise spent measuring and mixing. And because results are almost instant, it plays a significant role in boosting your morale and confidence.
UV resin works best with small and flat pieces. It would be impractical to place large pieces under a UV lamp.
Think keychains and jewelry items like cabochons and bezels for earrings, rings, and pendants. It is also good for coating and sealing small surfaces to waterproof them.
When To Use Epoxy
If high-quality and durable finished products are your top priority, then go for epoxy. Its longevity is unmatched and is suitable for gifts and products for sale.
Although it has a slightly complex preparation process and painfully long curing time, the end results are worth the trouble and wait.
What project is epoxy good for? Epoxy is suitable for making 3D objects of all sizes, big and small. It doesn’t rely on UV light activation to cure and has a greater maximum layer thickness; you can cast more oversized items.
You can use epoxy for pretty much anything, like jewelry, utility objects like tumblers, ashtrays, dishes, and decor centerpieces. It is also ideal for bigger projects like sealing floors, kitchen countertops, vanity tops, and tables.
Epoxy is also fantastic for bonding two surfaces and filling in gaps.
Final Thoughts
We hope this overview has cleared any confusion you had before. You now know what to do and expect with UV resin and epoxy and which one is more suitable for your project.
To wrap things up, there are a few crucial points to remember. Both UV resin and epoxy are synthetic resins made from toxic solvents. These escape as emissions during preparation and while hardening.
It would be best if you took safety precautions anytime you are handling either product. Always wear a mask and keep the work area well ventilated. The good thing is once they fully cure, they become stable and are no longer toxic. Some are even food-safe.
Also, both UV resin and epoxy will yellow over time, so do not be surprised when it happens. However, the ambering process takes place much faster with UV resin than with epoxy. The quality of the product is key!
DIY Alex has a great video explaining the differences between UV resin and epoxy. Check it out below.
Up Next: Is Epoxy Food-Safe? – Everything You Should Know
