Why Is UV Resin Sticky After Drying?

A close-up image of a dried UV resin with a sticky texture.

If you’ve ever used UV resin, the process is simple: mix the resin and hardener together, apply it to your project, cure it with UV light, and voila!

It’s supposed to be a quick and easy way to add a professional-looking finish to your work. But sometimes, things don’t go as planned. You might find that your UV resin is still sticky after it’s been cured.

Sticky resin can ruin projects and cause a lot of wasted time and material, so it’s essential to understand the causes and how to fix them.

In this article, we’ll explore some of the reasons why your UV resin is sticky even after doing everything right, as well as provide some tips on how to fix it.

But let’s first break down what a UV resin is, so we can all be on the same page.

What is UV Resin –

UV resin is a type of hard plastic that is cured using ultraviolet light. It is often used for making jewelry, crafts, and models. It is also used in some medical applications.

It is made from two parts: a base and a curing agent. The base is usually made from polyurethane or epoxy, whereas the curing agent is usually made from photoinitiators.

When these two parts are mixed, they create a reactive mixture that hardens very quickly when exposed to ultraviolet light.

Why Is Your UV Resin Sticky After Drying –

A person examining a sticky UV resin surface with various tools.

If you’ve ever used UV resin, you know there are times when the sticky feeling never really disappears. Even after the resin has dried, it can still be tacky to the touch.

This can be frustrating, especially when creating a smooth, polished surface. So why is your UV resin still sticky after drying?

There are a few possible explanations:

1. One is that your resin isn’t fully cured. UV resin must be exposed to ultraviolet light to cure correctly. If you don’t have enough exposure to UV light, the resin will remain tacky.

2. Another possibility is that your resin is too thick. If the ratio of resin to hardener is off, or if you add too much pigment or fillers, the resulting mixture can be too thick and cause a sticky feeling.

3. Finally, it’s possible that your curing environment wasn’t ideal and was maybe too humid. UV light must be strong and direct to cure correctly, so if you tried to cure your resin in a dim or shady spot, it might not have cured completely.

How To Fix Sticky UV Resin: What Are Some Solutions –

As mentioned in the text, UV resin occasionally becomes sticky after curing. If your UV resin still feels tacky after it has thoroughly dried despite these variables, you might try the following:

A series of step-by-step images showcasing the curing stages of UV resin.

1. Sanding: Use fine-grit sandpaper if your resin starts getting sticky. This will help to smooth out the surface and make it less sticky. This can be time-consuming, but it’s worth it if you want a perfect finish.

If only a portion is tacky, you can sand off the sticky resin from that area to get a UV resin with a matte finish. (check the best way to sand epoxy resin)

2. Recoating: Recoat with a fresh layer of polymer and hardener if it feels sticky. Recoating the piece with more resin is often the easiest solution. Apply another layer of resin over the top of the sticky area and allow it to cure.

This will usually create a smooth, non-sticky surface.

3. Using a Sealer Spray: If recoating doesn’t work or you don’t want to add more resin layers, use a sealer spray.

Sealer sprays are designed to create a barrier between the resin and whatever comes in contact with it, prevent sticking, and make cleanup a breeze.

To use a sealer spray, hold the can 6-8 inches away from the piece and spray evenly over the surface.

A person wearing gloves and using proper tools to handle UV resin.

4. Heating the Resin: You can try heating the resin slightly. This will help evaporate some moisture and make the UV resin less sticky. With some patience, it will make it more fluid and easier to spread.

You can do this by using a hair dryer or placing the resin in a sunny spot for a few minutes. If you find that your UV resin is still sticky after trying these solutions, you may need to replace it.

Sometimes, the sticky problem can be caused by a faulty batch of resin. If this is the case, you will need to get a new batch of resin and start again.

Things To Keep In Mind When Handling Sticky UV Resin –

Remembering a few things when handling sticky uv resin would be best.

1. Wear gloves – The resin can be very sticky and stick to your skin if you are not careful.

2. Do not touch the resin with bare hands since the resin will stick to them and cause irritation.

3. Cover your workspace with plastic sheets or other materials that can catch the resin splashes, like paper towels or newspapers.

4. Avoid breathing the dust created by cutting and sanding at all costs! This may be difficult if you have allergies or asthma, but it is essential!

Keep the area around you as clean as possible by using disposable wipes or wet paper towels to clean up spills.

How to Avoid Getting Sticky UV Resin –

A showcase of finished UV resin pieces with a flawless, non-sticky surface.

By now, you probably know how frustrating it can be to have sticky or tacky UV resin even after the whole curing process; here are a few tips to avoid it the next time:

1. When you start working with the resin, mix up a small batch to get a feel for how much you’ll need and how long it will take to cure. This way, you won’t waste any material and can adjust your timing.

2. Make sure your work surface is level and smooth before starting. If there are any bumps or divots, the curing process will be uneven and could lead to sticky spots.

3. Pour the resin into your mold or work surface once you’ve mixed the resin according to the instructions. Again, pour slowly and evenly so the curing process is as consistent as possible.

4. Keep a clean workspace; this will help prevent accidents and make the resin even more sticky or dirty.


Is it normal to have residual stickiness on my UV resin after trying it?

No, this is not normal. The sticky feeling you describe is caused by the resin not being treated completely.

Stickiness or Tackiness can be caused for several reasons, as explained above. Ensure you take all preventive measures for the process to go seamlessly.

How To Avoid UV Resin from Getting Sticky in the first place?

To avoid this problem, use a UV resin with higher molecular weight (polymerization degree) and lower molecular weight oligomers (1-3).

The higher molecular weight resin has more solids in the solution, and these solids do not absorb as much light as the low molecular weight resins so the high molecular weight resin will have less light absorption.

Does Sticky UV Resin Deteriorate its Quality?

When it comes to UV resin, it’s essential to know that the quality can diminish if the resin is sticky even after it cures. This is because the sticky residue can attract dirt and dust, which can then cause the UV resin to turn yellow and degrade over time.

If your UV resin gets sticky, it’s best to clean it immediately. Overall, it’s essential to be aware that the quality of your UV resin can decline if it’s not properly cared for.

If you keep an eye on your resin and clean it regularly, you can prolong its lifespan and ensure that it remains to look its best.

Conclusion –

After analyzing this subject in further detail, it can be said that several elements, such as UV light, humidity, and how well you combine your materials, can be responsible for UV resin becoming sticky after curing.

If your UV resin isn’t dry before utilizing or processing it further, give it more time to dry. After thoroughly drying, the polymer produces the desired glossy surface and becomes more robust and presentable.