Everything You Need To Know About UV Resin
I thought I would make this post because of how much Amazon pesters me to answer questions regarding UV resin and I know many of you were able to learn and benefit from my other craft posts which focused more on epoxy. Today I'm going to cover all the things I have learned using UV resin, which is something I use almost exclusively for many of the items you see in my Etsy shop.
What is UV resin?
UV resins are photochemicals that react to different wavelengths of UV (sunlight) to cure. This allows for a much shorter cure time and longer work time than epoxy resin, as UV resin will not begin to cure / harden until it is exposed to UV light. In the photos above, you can see the two main types/brands of UV resin I typically use for the creation of my projects, Solarez and Limino, both of which can be purchased on Amazon (Solarez has its own website, but shipping is not free though Amazon only has some of their products). While Solarez is known for surfboard creation and repair, boat repair, etc. It is one of the few UV resins that can be used to create larger projects such as these Fairy Garden Jars you see below.
Normally, however, UV resin is used for smaller projects - jewelry, coating, small casts, and the like. It is practically the same chemical combo found in UV nail polish. These chemicals may be triggered to harden using the same UV lamps one would see at a nail salon, though not all UV lamps or torches cover the full spectrum of UV wavelengths as sunlight (more on this later). I rely on UV resin for the creation of my popular rune sets, as they require more detail and time to fully create than the 30-45 minute work time one typically has with epoxy. Below are some examples of items I have in the shop made primarily with UV resin.
UV resins are typically non toxic and are not harmful to the environment when cured or uncured. The resin itself shares similar properties to epoxy but can have a much lower viscosity in general, making it more ideal for casting and coating than doming. UV resin does give off an odor when curing (Solarez is the WORST even when not curing), much more so than epoxy.
Pros & Cons of UV resin
Pros:
No mixing. UV resins are ready to go from the bottle.
Longer work time, shorter cure time. Great for making multiple projects at once or highly detailed, smaller projects. UV resin fully cures in approx 5 mins in full sunlight.
Great for clear casts and adding a glossy finish to any project.
Bonds to metal, wood, plastic, etc. Making it great for quick fixes.
Most are self degassing and self leveling.
Easier to handle. No component mixing means you can't possibly ruin your project from the get go.
Accepts most Inclusions / pigments one would use with epoxy
Waterproof when cured.
Cons:
Expensive. UV resin will average $65+ (for 1000g) USD for the equivalent of a 32oz epoxy combo for $20+. Solarez is on the cheaper side, but harder to work with.
Fickle. UV resin will produce bubbles that don't want to surface, must be used in very thin layers, prone to shrinkage, and cannot cure if using opaque or dense Inclusions or pigments.
Can only be used with clear silicone molds. Plastic molds tend to adhere / melt to UV resin. Solarez may be used with an MEKP catalyst to get around this, but not foolproof.
May only be used for small projects.
Must purchase UV lamp / torch to cure, but some only cure with certain wavelengths or sunlight itself. Can over cure and become brittle or undercure and be tacky.
Even clear but detailed molds may not cure correctly.
So, you may notice there are more cons than there are pros when it comes to UV resin. This is absolutely true- for cost effectiveness alone, unless you are looking to mass produce something or need more potability / work time for your project (as I do), I recommend avoiding UV resin and going with epoxy which will usually even yield better overall results.
If you DO decide to try UV resin or have tried UV resin, you may run into a few problems initially that will cause you to trash projects and become frustrated. Never curing resin is a popular complaint, this next portion of this post is entirely dedicated to troubleshooting UV resin in order to better help you achieve the results you are looking for.
Using & Troubleshooting
There are many different brands of UV Resin available. Save for Solarez, the ones that come in the big or small tubes like the Limino resin shown (I've used brands Miraclekoo, Decoroom, DIY, Let's Resin, Solarez, SooKoo, and Limino) are pretty much the same product selling for around the same price per milligram / fluid oz. They all have about the same viscosity and will generally yield the same results and have the same average cure time.
Note: Solarez is more of a polyester based resin or can be acrylic based depending on which of their products you purchase. It has a very strong odor and is more liquid than these others. It is also fairly cheaper (Almost half the price) and can be purchased in larger quantities. Unfortunately, even though the price tag is enticing, I really don't recommend it. It is very fickle with the UV wavelengths used to cure it. If you are trying to do any indoor project using a UV torch or lamp, you are going to want to even then drop an extra $20-$60 on a multi spectrum UV lamp to cure your project. You will find that you have to intermittently expose the resin to light or it gets an orange peel/puckered texture- sometimes the light will even literally burn right through your project. It can even burn or damage your mold, as Solarez gets very hot when curing even though it is formulated to not get as hot or combust when using UV light to cure, which is something, I guess.
However, Solarez can be used with an MEKP catalyst, allowing you to dual cure it using sunlight / UV light. This allows Solarez to be used with opaque pigments and can be used for larger projects. The catalyst was not initially included with the resin, but the manufacturer began including it for some reason. The ratio is 6 drops of MEKP mixed into 1 fluid ounce of Solarez. 6:1. With the MEKP catalyst, your project will fully cure in 30 mins (using sunlight or UV light to help it along) but it is prone to becoming overheated, still requiring small layers to be cured one at a time to avoid combustion.
If you're going to try UV resin, I recommend trying any of the brands above, save for Solarez. Grab a 50-120g bottle to try and see if you like it. I recommend beginning making something simple like a pendant or earrings using a clear silicone mold or open back bezel. Mica pigments and most alcohol inks will work with UV resin the same way they work with epoxy and UV resin also creates a super clear glossy finish that may be used to gloss and spruce up cured epoxy projects.
So you took the dive and purchased your UV resin? You've got problems? Yea, tell me about it.
•My Project is Super Tacky! What do?
This is common and will vary from product to product, but usually isn't the product. So before you go flaming the foreign manufacturer who doesn't understand you anyway, ask yourself the following and try these methods to solve the inevitable tacky problem:
How long did you cure? The average cure time shown on the bottle is just that, an average. This doesn't mean that your project will cure in five minutes under your UV lamp. Not all UV lamps are made equal. For starters, check the packaging, but most UV resins require your lamp to be 36w+, so write that off immediately. If your lamp is producing less wattage, than it's not going to cure your UV resin. If you're using a lamp that is 36w+ or your UV resin claims to cure under 36w, then take a look at your lamp itself. Most nail salon UV lamps are either table shaped or dome/cave shaped. If you're using a table shaped lamp on a 3D mold / project, the light is unable to penetrate the sides and back of the mold. This style lamp will only work to cure projects in open back bezels or free hand, flat coatings. If using a dome shaped lamp then the majority of the UV light is found at the back of the lamp. If you have your project at the front or sides, it is unable to be fully penetrated by UV light at all angles.
Try turning your project,curing it for a minimum of 5 minutes on each side. Using finger cots, remove your project and let it cure free form. It shouldn't be so tacky that it sticks to your work area at this point, but if it is, then there is only one solution:
Let it cure in actual sunlight for 10-20 minutes, turning it so that every angle sees light. Typically, your UV lamp doesn't offer the same UV light wavelengths as pure sunlight, and you can buy new lamps or torches to test, but sunlight is free.
If your project is still tacky after all these measures, you've tried adding a new layer of clear resin to it and allowing it to cure in sunlight.
If this doesn't work, think about your Inclusions, your glitter, your pigments etc. If your project is nearly opaque, then you'll need to tone it down if you're going to use UV resin.
If NOTHING else, your product may indeed be a dud or became contaminated in some way. Unfortunately, it's not always easy to get in touch with the manufacturer, but if you order your product from Amazon, they'll more than likely allow you to return it.
My project is all bubbly? What do?
Bubbles are always a problem, whether you're using UV resin or epoxy. Little tiny bubbles always form, especially around the edges of the mold or embedded within details in the design. Don't forget, you have infinite work time with UV resin. This means that you have as long as you want to work out the bubbles.
Use a toothpick to pop tiny bubbles at the bottom of the mold or dislodge them to bring to the surface. Be careful though because you don't want to leave little scratches on your mold or puncture it.
Use a torch to pop bubbles on the surface. A grill lighter, regular lighter, or whatever will do the trick. Make sure you hold the flame a good inch or so away from the surface. It will catch fire and your mold possibly will too. Do so carefully! I run the torch across the top layer every time I add something to the resin to remove any bubbles it gives off. This also works for epoxy.
Blow on it. Some people claim the heat of your breath will pop surface bubbles, but I have had no success with this method.
Warm your resin. Stick your UV resin in a plastic bag or something air tight. Allow some water to heat to near boiling on the stove before pouring it over your resin bottle in a bowl or basin. Do not stick your resin in the microwave or oven or anything crazy.
Stir slowly. Stir inclusions like glitter and pigments slowly, scraping the sides and bottom. This will prevent air bubbles kicking up into your mix and oxygen being introduced into your pour.
Try pigments. For some weird reason (most likely due to changes in viscosity), resin projects with pigments, glitter, and the like have less tendency toward bubbling than clear casts.
Are your bubbles huge? This may be because your pouring super thick layers of resin and all sides have not cured properly. Your layers should only be 1mm thickness maximum when using UV resin.
My project has come out warped, not even, has divots , etc.
If you are curing your layers quickly, your project is heating. When you add more resin over top of this hot resin in a hot mold, this will not only cause more bubbles but also lend to shrinkage. Allow your project to cool to room temp and have some downtime between curing. This will also protect your molds that will become damaged from overuse / overheating and cooling.
With Solarez, this is key to having a beautiful project at the end of the day. Even though it is formulated to not overheat if exposed to sunlight, Solarez will get this orange peel like texture on the surface layer if overexposed.
Yes, there is such thing as overcuring as well, and it will make your project brittle and even flakey, but this is normally not the biggest complaint with UV resin.
So why even buy UV resin?
UV resin has its perks. In a pinch, it makes for a clear, glossy finish that will cure / harden quickly in the sun or with a UV lamp that one would be waiting 24-48 hours for with epoxy. It can be used to repair epoxy projects and fill small divots as well as the ability to bond to pretty much anything makes it useful to have around. It is convenient to use due to the fact that you don't have to mix it, it is easy to pour and compatible with most inclusions. It is also ideal for its extended work time as it will not cure until exposed to UV light. This allows you to create highly detailed clear cast jewelry and other projects you wouldn't be able to assemble and detail before epoxy would begin to cure.
I hope this helps everyone who is having trouble with UV resins or those who have considered using UV resin as an alternative to epoxy. If you have any other questions you would like answered or are someone adept with UV resin that would like to share, please do so! Good luck!
~Samantha
Owner/ Designer/Creator blursedbaubles.etsy.com