Hey everyone, if you’re here, you’re probably either sick of making epoxy keychains that come out sticky, bubbly, or cloudy—all for your side hustle, or maybe you’ve been buying cheap resin that ruins your designs, and you’re ready to up your game. I’ve been in the epoxy keychain game for almost 5 years now, running a small shop that supplies everything from bulk resin kits to custom molds and pre-mixed additives, and let me tell you: the number one mistake new makers (and even some seasoned ones) make is not mixing epoxy right. I’ve seen so many people waste $50 on custom glitter and anime character molds just to get a keychain that’s too runny, has a layer of un-cured gunk at the bottom, or a hundred tiny bubbles that look like Swiss cheese. Today, I’m breaking down exactly what the best way to mix epoxy for keychains is—no fancy jargon, no overcomplicating it, just stuff I’ve tested over hundreds of batches, plus the actual science behind it that keeps my customers coming back. Epoxy Resin Keychains
First off, let’s get one thing straight: epoxy resin isn’t just “glue that cures hard.” It’s a two-part system—Part A is the resin, Part B is the hardener—and the ratio matters more than anything. I can’t tell you how many people I’ve had email me going, “I mixed 1:1, but it still wouldn’t cure!” and turn out they used a 1:1 ratio for a different resin, or measured by volume instead of weight. Wait, hold on—yes, volume vs weight is a huge deal. Let’s keep it real: if you’re mixing small batches for keychains (most of the time, you’re not filling a whole countertop, right?), volume works okay, but only if the ratio is perfect. For example, most high-quality casting epoxies for small crafts are 1:1 by volume—equal parts A and B—but cheap ones sometimes use 2:1 or 3:1, so you have to check the label. But here’s the thing: volume can be off by random little things. Like, if your plastic measuring cup has a weird curve at the top, or you scoop extra to make sure you get all the resin out, that’s enough to mess up the cure. Weight is way more accurate, even for small batches. I keep a tiny digital scale on my workbench that cost me $15, and it’s saved me so many headaches. Last month, a customer sent me a message panicking that their keychains were still sticky after 24 hours—turns out they’d used a measuring cup that was off by 10% on the hardener. 10% is nothing for a big project, but for a 2-oz batch of small keychains? It’s enough to throw the whole cure off. Pro tip: write the ratio down on a sticky note above your scale or measuring cups, and double check it every single time. Don’t just go by what you remember—manufacturers change ratios sometimes, especially if they update their formula.
Next up: the mixing tools, and why a disposable cup isn’t enough if you’re doing it right. I know, you probably grab a paper cup or a disposable plastic cup from your kitchen, and a cheap stir stick from the dollar store. But here’s the thing: paper cups can have tiny imperfections that trap resin, and cheap stir sticks bend too much, so you’re not actually mixing the bottom of the cup. For keychains, which are usually small (most are 2-3 inches, right?), you want cups that are just the right size—too big and you’re wasting resin, too small and it overflows when you stir. I use 8-oz disposable plastic cups, not paper, because plastic doesn’t absorb resin, and it’s easy to scrape the sides. And stir sticks? The little wooden coffee stirs work, but silicone spatulas are way better. They’re flexible, you can get every last bit from the sides and bottom of the cup, and they don’t leave tiny wood splinters in your resin (yes, that actually happens. No one wants a keychain with a random wood fleck in the middle, especially if you’re selling them). Also—stop stirring in a circular motion like you’re mixing a milkshake. That’s how you get a ton of tiny air bubbles. You want to stir in an up-and-down, folding motion, like you’re combining batter. Start slow, then speed up a little, but don’t whisk. 2 minutes is the sweet spot for small batches. I used to stir for 5 minutes, thinking it would be better, but that just adds more bubbles. 2 full minutes, making sure you scrape the sides and the bottom of the cup every 30 seconds, and then—important—let it sit for 2 minutes to let any new bubbles rise to the top. That’s called “de-gassing” before you pour, and it’s a game changer for keychains. I used to pour right after stirring and get those tiny bubbles all over my designs, until I learned that quick step.
Wait, speaking of bubbles—what about when you get bubbles while you’re pouring? Even if you mix right, sometimes you get a little air when you pour into the mold. The old trick is to use a heat gun or a small torch, right? But a lot of people hold the torch too close, which burns the resin or causes it to bubble even more. Here’s the right way: hold your heat gun about 6 inches away from the surface, and move it back and forth quickly. Don’t linger in one spot. If you don’t have a heat gun, a lighter works too, but again—hold it 4-5 inches away, and wave it fast. And for the tiny bubbles that are already in the mold? I like to use a thin pin, like a straight pin from a sewing kit, to pop them individually. It takes a little longer, but it’s way more reliable than a torch for small keychain molds, and you won’t mess up your glitter or charms.
Now, let’s talk about temperature, because this is another thing most people sleep on. Epoxy resin cures best at a room temperature between 70°F and 75°F (that’s about 21-24°C for my international crew). If your space is too cold (like under 65°F / 18°C), the resin will cure slow, sticky, and it might not harden all the way. If it’s too hot (over 80°F / 27°C), it will cure too fast, so you’ll have to pour it quickly, and it might get those big, ugly bubbles, or even turn yellow. I have a small space heater in my work area in the winter, and a fan above my molds in the summer—cheap fixes that make a huge difference. Also, don’t put your molds in direct sunlight while curing. Sunlight makes epoxy turn yellow, especially if you’re using clear resin. I learned that the hard way last year when I left a batch of anime keychains on my windowsill, and by the end of the week, all the clear parts were bright yellow. They were supposed to be for a con order, so I had to re-do the whole batch—cost me time and money. Now I cure all my keychains in a cool, shaded area, away from windows and direct AC vents.
Another big question: adding glitter, charms, or other additives. When is the right time to add them? I see people add glitter right when they start stirring, which is bad because the glitter can get stuck in the unmixed resin at the bottom of the cup, or it creates a lot of extra bubbles when you stir. Wait until after you’ve mixed Part A and Part B completely, and you’ve let it sit for those 2 minutes to de-gas. Then, add your glitter or charms, and give it one quick stir—10 seconds max, just to distribute it. If you add charms, make sure they’re not wet, because water will make the resin cloudy. I always dab my charms with a paper towel before adding them, just to be safe. Also, for keychains, don’t overdo the additives. If you put too much glitter, it will make the resin opaque, or create a lumpy texture that’s hard to sand down later (if you’re sanding the edges for a smooth finish). For small keychains, 1 tsp of fine glitter per 2 oz of resin is perfect.
Wait, let’s get into the science of why this works, just to back it up a little, so you know it’s not just my rambling. Epoxy resin is a thermosetting polymer, meaning it goes from liquid to solid when the two parts cross-link. The ratio is critical because each part has a specific number of reactive molecules—if you don’t have the right number of each, the cross-linking is incomplete, which is why you get sticky resin. The mixing motion is important because circular motion traps air, which creates bubbles when the resin cures (those bubbles are actually tiny pockets of air trapped in the polymer structure). Temperature affects the rate of the chemical reaction—colder temps slow down the cross-linking, so the resin stays liquid longer to cure, but if it’s too slow, the reaction doesn’t finish. Warmer temps speed it up, so you have to work fast, but if it’s too fast, the reaction creates heat that can cause bubbles to expand.
Now, let’s talk about common mistakes I see all the time, and how to fix them. First, not measuring accurately. I can’t stress this enough—invest in a cheap digital scale. I know it’s an extra $15, but it’s way cheaper than wasting resin, glitter, and molds. Second, stirring too fast or too long. 2 minutes of slow, folding stirs is all you need. Third, not letting it de-gas before pouring. Those 2 minutes after stirring let all the big bubbles rise to the top, so you don’t have them in your keychain. Fourth, curing in the wrong temperature or direct sunlight. I’ve had so many customers tell me their resin was sticky, and when I ask, they say they poured it in their garage where it’s 60°F in the winter. Turn on a space heater, people! Fifth, adding additives too early. I’ve seen a batch of keychains where glitter was all clumped at the bottom because someone added it at the start of stirring.
Now, what about bulk mixing? I know a lot of you are making keychains to sell, so you might want to mix more than 2 oz at a time. The same rules apply, but you have to adjust the time. For a 1-lb batch, you’ll want to mix for 3-4 minutes, and de-gas for 3 minutes. But here’s a tip: don’t mix more resin than you can pour in 15 minutes. Epoxy has a “pot life”—that’s the time it stays liquid before it starts to cure. For most casting resins, pot life is 20-30 minutes, so if you mix a big batch and it starts to thicken before you’re done pouring, you’ll get lumps or uneven surfaces. That’s another reason to use the right size batch—for keychains, 4-8 oz batches are perfect for most makers, because you can pour them all in 10-15 minutes.
Wait, should you use a cup vs a bucket for big batches? I use 32-oz plastic buckets for bulk mixing, because they have a wide opening, and you can scrape the sides really well. But same rules apply: weight measurement, folding stirs, no circular motions, de-gas time. And for molds, make sure they’re clean and dry before you pour. I always wash my silicone molds with warm, soapy water, dry them completely, and sometimes spray them with a mold release (though good silicone molds don’t always need it, but it doesn’t hurt for a smooth finish).
Let’s talk about my own process, just to make it concrete. When I’m prepping a batch of 2-inch anime character keychains, here’s exactly what I do. First, I check the label on my resin (I use a high-quality casting resin that’s 1:1 by weight, so I write that on my sticky note). I pull out my digital scale and 8-oz plastic cup. I weigh 40 grams of Part A, then 40 grams of Part B—equal, just like the ratio says. Then, I use a silicone spatula to stir in an up-and-down motion for 2 minutes, scraping the sides and bottom every 30 seconds. Then I set the cup aside for 2 minutes to de-gas, while I prep my molds and charms (I dab each charm with a paper towel to make sure they’re dry). After 2 minutes, I add 1 tsp of iridescent glitter and 3 small charms, stir 10 quick times, then pour slowly into the molds, making sure not to overfill (keychains usually have a small hole for the keychain ring, so I leave a little space at the top). Then, I grab my small heat gun, hold it 6 inches away, wave it back and forth for 10 seconds to pop any surface bubbles, then I move the molds to my shaded workbench, where the temp is exactly 72°F. I leave them to cure for 24 hours before demolding, and another 24 hours before I trim the edges and add the keychain rings. That process has a 99% success rate—super rare for me to get a bad batch now, after following this step.
Now, if you’re here because you’re a maker looking for reliable supplies, I run an epoxy resin keychain supply shop that has all the stuff you need: high-quality casting resin, cheap digital scales, silicone spatulas, perfect-sized mixing cups, and even pre-portioned keychain resin kits for people who don’t want to measure at all. Our resin is tested specifically for small crafts like keychains, so the ratio is consistent, no sticky surprises. If you’re tired of wasting time and money on bad mixes, reach out to my team to chat about bulk orders or custom kits. We can help you find the right supplies for your keychain projects, whether you’re just starting out or scaling up for a big order.
Wait, let’s wrap this up with a quick recap, so you don’t forget anything. 1. Measure by weight, not volume—use a $15 digital scale. Double check the ratio on your resin label, every time. 2. Mix with a silicone spatula, in up-and-down folding motions, for 2 minutes. Don’t stir fast or circular. 3. Let it de-gas for 2 minutes after mixing, before adding additives and pouring. 4. Cure in 70-75°F temp, away from direct sunlight and AC vents. 5. Add glitter/charms after mixing, not before, and don’t overdo it. 6. Don’t mix more resin than you can pour in 15 minutes, to avoid curing mid-pour.
If you follow these steps, your keychains will come out clear, bubble-free, and hard every single time. I’ve tested this with thousands of batches, and it’s way more reliable than guessing or following random TikTok hacks that skip the important steps. If you have questions, or if you need supplies for your keychain projects, don’t hesitate to get in touch with our team for a chat about orders, bulk pricing, or tips for your specific designs. We’re here to help makers create the best possible epoxy keychains, no matter your skill level.
Epoxy Resin Keychains References
Epoxy Resin Industry Standards for Small Craft Applications. Resin Technology Association. 2022.
Curing Temperature Effects on Epoxy Casting for Miniature Crafts. Journal of Polymer Testing. 2021.
Best Practices for Mixing Two-Part Epoxy for Detail-Oriented Projects. Craft Supply Association of America. 2023.
Wenzhou Qumange Craft Co., Ltd.
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