How to Mix & Pour Resin: A Step-by-Step Guide for Beginners
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How to Mix & Pour Resin: A Step-by-Step Guide for Beginners
By Nikolai Botsman | bmmold.com
Most resin problems — sticky surfaces, cloudy pieces, trapped bubbles, uneven cure — trace back to the mixing and pouring stage. Not the resin brand. Not the mold. The process. Get this part right and the rest becomes much easier.
This guide walks through every step in order: measuring, mixing, pouring, handling bubbles, and setting up to cure. It's written for two-part epoxy resin, which is the right starting material for most jewelry, mold casting, and beginner projects.
Before You Mix: Gather Everything First
Once resin and hardener are combined, the clock starts. You cannot pause the process partway through to find a missing tool. Before you open anything, have in front of you:
- Two graduated mixing cups (one for measuring, one for the second mix)
- Mixing sticks (wood, silicone, or clean plastic)
- Nitrile gloves on your hands
- Safety glasses
- Your molds, set on a level surface
- Any colorants, inclusions, or additives you plan to use
- A butane torch or heat gun for bubbles
- A timer
Working temperature matters. The room should be between 70–80°F / 21–27°C. Below 65°F / 18°C, epoxy cures slowly and incompletely, often staying tacky. Above 85°F / 29°C, it can cure too quickly, build heat in the container (called "exotherming"), and produce yellowing, cracks, or excessive bubbles. If your workspace is cold, warm it with a space heater before you start — don't try to compensate by changing your process.
Step 1: Measure the Ratio
Every two-part epoxy has a specified mix ratio — the proportion of resin to hardener required for the chemical reaction to complete correctly. The most common ratio for craft and jewelry epoxies is 1:1 by volume (equal parts). Some products use 2:1 resin to hardener by volume. A few use ratios by weight rather than volume.
Check your specific product's instructions. Do not assume. Using the wrong ratio — even slightly off — can mean the piece never fully cures, stays permanently flexible, or develops sticky patches that can't be sanded or fixed.
To measure 1:1 by volume:
- Pour resin into one side of a graduated cup to your chosen volume line (e.g., 15ml)
- Note that exact level
- Add hardener up to the same volume mark (15ml)
For small amounts, use measuring cups with fine gradations — those tiny milliliter lines matter more when your total volume is 10–20ml than when it's 100ml.
Measuring by weight (if your instructions call for it): use a digital kitchen scale. Tare the cup, add resin to the required weight, then add hardener. Weight ratios and volume ratios are different — don't swap them.
Step 2: Mix Thoroughly
This is where most beginner mistakes happen. The mix needs to be complete — not almost complete. Unmixed material along the sides and bottom of the cup is the direct cause of sticky patches, soft spots, and incomplete cure in the finished piece.
The two-cup method:
Combine resin and hardener in Cup 1. Mix for a full 3 minutes. Scrape the bottom of the cup as you go, and drag the stir stick along the sides to incorporate any unmixed material clinging to the walls. Mix at a moderate pace — not so fast that you whip in a lot of air bubbles, not so slow that you're barely moving material around.
Pour everything from Cup 1 into a fresh Cup 2. Mix for another 60 seconds, again scraping sides and bottom.
The purpose of Cup 2 is simple: any unmixed material that was stuck to the walls of Cup 1 stays behind. The resin in Cup 2 has been fully homogenized.
What the mixture should look like: fresh from the bottle, resin and hardener are usually slightly different in color — one may be slightly amber, the other clear, or they may be the same. As you mix, watch for streaks. When no streaks are visible and the mixture is uniformly clear (or uniformly colored if you've added pigment), mixing is complete. The mixture will be slightly cloudy from air bubbles — that's normal and will clear on its own.
Do not rush this step. Three to four minutes of mixing feels long when you're looking at a cup of liquid. Do it anyway.
Step 3: Add Color (Optional)
If you're adding colorant, do it at the end of the second cup mix — after the resin and hardener are fully combined. Add pigment to incompletely mixed resin and you can't tell if your streaks are unmixed hardener or pigment swirls.
General amounts by colorant type:
Mica powder: Start with about ¼ teaspoon per ounce (30ml) of mixed resin for a mid-tone metallic. Add more for deeper color, less for a translucent shimmer. Mica powder doesn't inhibit cure and is very forgiving.
Alcohol ink: 2–4 drops per ounce. Stir gently to preserve marbling effects, or stir fully for solid color. Note: too much alcohol ink can inhibit curing in some epoxy formulas. Stay under 5% by volume.
Resin-specific liquid dyes: Follow the manufacturer's recommendation, usually a few drops per ounce. These are formulated to not interfere with curing.
Acrylic paint: Possible in small amounts (under 3–5% by volume), but introduces water that can cause cloudiness and adhesion issues. Resin-specific pigments are better. If you do use acrylic, use it sparingly and make sure it's fully mixed in.
Step 4: Let It Rest Before Pouring
After mixing, let the cup sit undisturbed for 2–3 minutes. Bubbles introduced during mixing will rise to the surface and pop on their own during this time. This is especially helpful for small jewelry molds where you don't want to do multiple torch passes on delicate pieces.
This rest time also matters for temperature. If your room is slightly cold and the resin thickened up slightly, the rest period lets it come back to working viscosity.
Don't wait too long — if your resin has a 30-minute working time, this rest eats into it. 2–3 minutes is the right balance.
Step 5: Pour
Pour close to the mold surface and slowly. Pouring from a height of more than a few inches splashes resin against the mold walls and introduces air. Hold the cup just above the mold cavity and let the resin flow in gently.
For small jewelry molds, consider using a toothpick or the tip of a stir stick as a directing tool rather than pouring directly from the cup. This gives you far more control over how much resin goes into each small cavity.
Fill level: pour to just at or slightly above the top of the mold cavity. Surface tension will hold a small amount of resin above the rim, creating a slight dome on the back face of the piece. This is preferable to underfilling, which can leave a flat concave back.
Working with inclusions: if you're embedding dried flowers, glitter, shells, or other inclusions, there are two approaches:
- Single pour: add inclusions to the mixed resin in the cup and pour together. Works for glitter and fine particles that disperse well.
- Two-layer pour: pour a base layer first (just enough to cover the mold bottom), let it gel for 30–60 minutes until tacky but not fully set, place inclusions on the surface, then pour a second layer over the top. This method controls exactly where inclusions sit and prevents them from sinking.
For botanical pieces (pressed flowers, leaves), the two-layer method is standard. It lets you place the flower face-down against the mold surface so it shows through the front of the cured piece.
Step 6: Remove Bubbles
Surface bubbles are normal after pouring. Small ones will pop on their own; larger ones need help.
Torch method: hold a small butane torch 3–4 inches above the resin surface and pass it quickly across. The heat briefly lowers the viscosity and pops bubbles through a combination of reduced surface tension and slight convection. Keep the torch moving — staying in one spot can scorch the resin, cause yellowing, or raise the temperature enough to accelerate the cure unevenly. Two or three quick passes are better than one long one.
Heat gun method: works the same way but with less concentrated heat. Keep it moving and at least 4–6 inches away.
Breath method: exhale gently across the surface. The CO₂ in breath breaks surface tension and pops small bubbles. Works well for small jewelry molds where a torch is overkill and there's risk of overheating a tiny pour volume.
Check the surface again 5–10 minutes after your first bubble pass — new bubbles may rise from within the pour as the resin settles. A second quick pass takes care of them.
Step 7: Cover and Cure
Once poured and debubbled, cover the molds to keep dust and particles out of the resin while it cures. A cardboard box placed over the molds works perfectly — it doesn't need to be airtight, just a barrier to airborne dust.
Cure on a level surface. Small jewelry molds will show tilting in the finished piece; check with a bubble level if you're not sure your table is flat.
Leave the molds undisturbed. Don't move them, check them, or prod the surface to test hardness — this disrupts the cure and can leave marks. Most jewelry epoxies are firm enough to demold in 18–24 hours. Wait the full recommended time before demolding, and know that full mechanical hardness continues to develop for 72 hours or more.
What to Do with Leftover Mixed Resin
Never pour unused mixed resin back into your stock bottles — once mixed, it's starting to cure, and contaminating your supply with partially cured resin will ruin the whole bottle.
Pour leftover mixed resin into a silicone cup or on a silicone sheet and let it cure completely, then dispose of the cured solid in regular trash. Cured epoxy is inert and non-toxic; uncured/liquid epoxy is not — never pour liquid resin down the drain.
Dispose of cups with uncured resin in a sealed bag in regular trash (not recycling). Let them cure out fully first if possible.
Signs That Something Went Wrong
Sticky surface after full cure time: ratio was off, mixing was incomplete, or the room was too cold. No fix — demold, sand any rough spots, and start fresh with more careful measuring.
Soft, flexible, or rubbery result: same causes as sticky. Some formulas produce a softer result when under-cured due to low temperatures. Putting the piece in a warm place (70–80°F / 21°C) for an additional 24 hours sometimes completes a partial cure, but this doesn't always work.
Cloudiness or white haze on the surface: usually amine blush — a reaction between hardener and atmospheric moisture/CO₂ that forms a waxy film. More common in humid conditions. Wash the surface with warm soapy water, dry thoroughly, and sand lightly with 400-grit before any topcoat.
Yellow tint: overheating during cure (torch held too long, room too hot) or low-quality formula. UV-stabilized epoxy resists ambient UV yellowing but still yellows from excessive heat during cure.
Bubbles trapped inside: pour was too fast, from too high, or the working temperature was too cold (making the resin too viscous to allow bubbles to rise). Slow down the pour, warm the workspace, and give the post-pour rest period more time before covering.
Quick Reference
| Step | Key number to remember |
|---|---|
| Mix ratio (most craft epoxies) | 1:1 by volume |
| Mix time | 3 min Cup 1 + 1 min Cup 2 |
| Rest before pour | 2–3 minutes |
| Working temperature | 70–80°F / 21–27°C |
| Demolding (typical) | 18–24 hours |
| Full cure | 48–72 hours |
| Torch distance | 3–4 inches, always moving |
What's Next
With the mixing and pouring process down, the next things to master are working with color (mica powder is the most beginner-friendly starting point) and understanding what your specific resin does as it cures — how quickly it gels, how it reacts to heat, and when it's at the right stage for second pours. Those are covered in the upcoming guides.
If you're casting into silicone jewelry molds and want to understand how inclusions behave at each gel stage, the guide on making resin jewelry covers those details.
Nikolai Botsman makes handmade silicone molds for epoxy resin at bmmold.com, shipping across North America.
Image Notes (for publishing)
Hero image:
Midjourney prompt: overhead view of hands carefully measuring clear epoxy resin into a graduated mixing cup on a wooden craft table, second measuring cup nearby, warm soft light, artisan workshop, film grain --ar 16:9
Unsplash search: epoxy resin mixing craft supplies
Image 2 (near mixing section):
Midjourney prompt: close-up of a wooden stir stick mixing clear two-part resin in a clear plastic cup, slight swirl visible, craft table background, natural window light
Pexels search: mixing resin stir stick cup
Image 3 (near torch section):
Midjourney prompt: small butane torch being passed over filled resin molds to remove bubbles, close-up, warm workshop light, silicone molds visible, no face visible
Pexels search: resin torch bubbles jewelry mold