You measured carefully. You stirred for a full three minutes. You poured it into the mould and waited overnight. And yet — sticky, soft, bendy resin that refuses to cure properly. If this sounds familiar, you are not alone. Resin mixing ratio mistakes are the single most common reason beginners end up with ruined pieces, wasted materials, and a lot of frustration.
The tricky part is that these mistakes are almost invisible while you are making them. A little extra hardener scraped from the cup wall, a few millilitres of resin left clinging to the spout, a quick eyeball measurement instead of a proper one — each of these feels harmless in the moment. But epoxy resin is a chemical reaction, not a recipe where you can adjust to taste. Even a 5–10% deviation in your ratio can leave you with resin that is soft and bendy after curing, or worse, permanently sticky.
This article breaks down exactly where those errors are creeping in — from the type of cup you use, to how you scrape, pour, and measure — and what to do differently starting with your very next batch. Whether you are working with a 1:1 or 2:1 system, the fixes here apply across the board.
Quick Answer: Why Is My Resin Still Sticky After 24 Hours?
If your resin is still sticky after 24 hours, the most likely causes are:
- Wrong ratio — too much or too little hardener relative to resin
- Inaccurate measurement — eyeballing volumes instead of weighing by grams
- Scraping the cup walls — pulling in partially mixed or unmixed resin
- Residue left in the measuring cup — one component sticking to the spout or walls
- Insufficient mixing time — under-mixed batches cure unevenly or not at all
- Temperature too low — resin cures slowly or stays soft below 24°C
Keep reading for the detailed breakdown and fixes for each of these. And if you want a deeper look at the sticky resin problem specifically, check out Why Your Resin Is Still Sticky After 24 Hours — and How to Fix It Before You Ruin the Piece.
The Ratio Basics You Cannot Skip
Every epoxy resin system comes with a specified mix ratio — usually printed on the bottle. Common ratios are 1:1 (equal parts resin and hardener by volume or weight) and 2:1 (two parts resin to one part hardener). Some specialty resins use 3:1 or 4:1 ratios.
This ratio is not a suggestion. It is the exact proportion needed for the chemical reaction between resin and hardener to complete fully. When the ratio is off, you end up with excess of one component that has nothing to react with. That leftover unreacted material is what stays soft, sticky, or flexible.
A very important point: volume ratio and weight ratio are not the same thing. Resin and hardener have different densities. If your brand specifies a 2:1 ratio by weight and you measure by volume, you are already working with the wrong amounts. Always check whether your product specifies ratio by volume or by weight — and measure accordingly.
For a full beginner-friendly breakdown of 1:1 vs 2:1 systems, read How to Choose the Right Resin Ratio for Your First Project: 1:1 vs 2:1 Explained for Indian Beginners.
How Your Mixing Cup Is Sabotaging Your Ratio
The problem with unmarked or poorly graduated cups
A lot of beginners start out using whatever plastic cup or container is lying around — old paint cups, random kitchen containers, even steel bowls. These have no graduation markings, which means you are guessing your volumes. Guessing introduces error, and error means resin mixing ratio mistakes.
Even cups that do have markings can be unreliable. Cheap disposable cups often have printed graduations that are off by 10–15%. That sounds small, but on a 100ml batch, that is 10–15ml of error — more than enough to leave your resin soft and bendy after curing.
Why resin sticks to certain cup materials
Resin and hardener are both viscous liquids, and they cling to surfaces. Rough or textured cup interiors hold more residue than smooth ones. Paper cups absorb small amounts of liquid into their walls. Narrow-bottomed cups make it harder to scrape cleanly.
This residue matters because if you pour your resin into the cup first, measure it, and then add hardener — any resin left clinging to the walls when you pour out the mix is resin that is not making it into your mould. Your actual poured ratio is now skewed toward hardener.
Silicone cups solve a big part of this problem. Resin releases cleanly from silicone surfaces, so almost nothing is left behind. The Silicon Measuring Cup/Jug (250ml) from Shrebhavi is a good example — it has clear graduation markings, a flexible body so you can squeeze out every drop, and resin does not stick to it the way it does to plastic or paper.
Cup size relative to batch size
Using a large cup for a small batch is another hidden source of error. If you are mixing 20ml of resin in a 500ml cup, the graduation marks are so far apart that reading them accurately is nearly impossible. Always use a cup that is appropriately sized for your batch. For small jewellery pours, the Silicon Measuring Cup (100ml) gives you much finer control over smaller volumes.
Measuring Mistakes That Are More Common Than You Think
How to measure resin without a digital scale — and why a scale is still better
Volume measurement using graduated cups is the most accessible method for beginners, and it works well when done carefully. But it has one major weakness: parallax error. When you look at a liquid in a cup at an angle, the meniscus (the curved surface of the liquid) can make the reading look higher or lower than it actually is. Always read the graduation at eye level, looking straight across at the marking.
A digital kitchen scale eliminates this problem entirely. Measuring resin and hardener by weight in grams is more precise than measuring by volume, especially for small batches. If your resin specifies a ratio by weight, a scale is not optional — it is the only accurate method. You can get a basic 0.1g precision kitchen scale for under ₹500 and it will save you far more in wasted resin.
The "top up" trap
This is a very common resin mixing ratio mistake. You pour your resin, realise you have slightly too much or too little, and try to top it up. Every time you adjust one component, you need to re-adjust the other to maintain the ratio. Most people do not do this — they just add a little more of whichever component seems short, and the ratio drifts further off.
The cleaner approach: measure both components separately in their own cups before combining anything. This way you can check each measurement before they touch each other.
Measuring both components in the same cup sequentially
Some tutorials suggest measuring resin first in the mixing cup, marking the level, then adding hardener on top. This seems efficient but it is problematic. The residue from the first component coats the walls and the graduation marks, making the second reading less accurate. It also makes it impossible to re-check either measurement independently.
Better practice: use two separate measuring cups — one for resin, one for hardener — then combine them into your mixing cup. Yes, it means more washing up. But it means your ratio is actually correct.
Pouring and Scraping Habits That Skew Your Mix
The scraping problem
Scraping the walls of your mixing cup with a spatula feels like the responsible thing to do — you want to use every drop, right? The problem is that the resin clinging to the walls of a mixing cup is often the last resin to get fully mixed. It has had less contact with the hardener, especially if your mixing motion was primarily in the centre of the cup.
When you scrape that partially mixed material into your mould at the end of the pour, you are introducing a pocket of off-ratio resin. This is a very common reason for soft spots in an otherwise cured piece.
The fix: mix thoroughly by scraping the walls during mixing (not after), and stop pouring before you get to the very last bit in the cup. A small amount of waste is better than a ruined piece.
Pouring too slowly from a viscous cup
When resin is cold or the ambient temperature is low (common in Indian winters or air-conditioned rooms), it becomes thicker and pours more slowly. This means more resin clings to the cup walls and spout as you pour. You end up losing more resin than hardener, because hardener is typically thinner and flows out more completely.
Warming your resin bottle slightly in a bowl of warm water (not hot — around 30–35°C) before measuring reduces viscosity and helps it pour more cleanly. This is especially useful if you are working in a room below 22°C.
Mixing stick technique matters too
Stirring only in circles in the centre of the cup leaves unmixed resin at the edges and bottom. Proper mixing technique involves scraping the bottom, dragging the spatula along the walls, and folding the mix — not just spinning it. Do this for a full 3–4 minutes for most epoxy systems.
A flat-bottomed mixing stick reaches the corners of a cup far better than a round dowel. The Resin Mixing Stick (10pcs) available at Shrebhavi has the right shape for this kind of thorough wall-to-wall mixing.
Choosing the Right Tools for Accurate Mixing
Getting your resin mixing ratio right is much easier when you have tools designed for the job. Here is what actually matters:
- Graduated cups with clear, accurate markings — silicone is best for easy release
- Appropriately sized cups — match cup size to batch size for readable graduations
- Flat mixing sticks — reach cup corners and walls properly
- Separate measuring cups — one for resin, one for hardener, combined into a third mixing cup
- A digital scale — for weight-ratio systems and small batches
- Disposable cups for one-off pours — avoids cross-contamination between sessions
If you are just starting out and want everything in one place, the Resin Mixing Set/Combo from Shrebhavi covers the basics well. For smaller jewellery and keychain work where you are mixing 20–40ml at a time, the 10pcs Mixing Disposable Cup (40ml) is a practical choice — small enough for accurate readings at low volumes, and disposable so there is no cleanup contamination risk.
Also see UV Resin vs Epoxy Resin for Small Moulds: Which One Actually Works Better for Keychains, Pendants, and Jewelry in Indian Humidity? if you are deciding between resin types for small pours — the mixing requirements are quite different.
Mixing Cup Comparison: Which One Should You Use?
| Cup Type | Resin Release | Graduation Accuracy | Reusable? | Best For |
|---|---|---|---|---|
| Paper / wax-coated cup | Poor — absorbs resin | Low | No | Emergency use only |
| Plastic disposable (PP) | Moderate | Medium (check brand) | No | Small batches, quick pours |
| Silicone graduated cup | Excellent — peels clean | High | Yes (100+ uses) | Most resin work, daily use |
| Glass measuring jug | Poor — resin sticks | Very high | Difficult to clean | Not recommended for resin |
| Steel bowl (unmarked) | Moderate | None | Yes | Only with a scale, not for volume measuring |
Safety Notes for Resin Mixing
Resin mixing is not dangerous when handled sensibly, but there are a few things worth keeping in mind — especially if you are working in a small Indian home studio.
- Wear nitrile gloves always. Repeated skin contact with uncured epoxy resin can cause sensitisation — an allergic reaction that gets worse with each exposure. Once you develop it, you may not be able to work with resin at all.
- Work in a ventilated space. Epoxy hardeners (especially amine-based ones) release fumes during mixing and curing. Open a window or use a small fan to move air away from your face.
- Do not mix resin in food containers. Even after washing, residue can remain. Keep your resin cups separate from kitchen use.
- Dispose of cured resin scraps as solid waste — do not pour uncured resin down the drain. Let leftover mixed resin cure in the cup, then discard the solid.
- Watch for exothermic heat. Large batches of mixed epoxy can heat up significantly. If your cup feels hot to the touch, pour it into a wider, shallower container immediately to spread the heat. See Deep Pour vs Thin Pour Epoxy in Indian Summers: Why Your Resin Overheats in May and What to Do About It for more on managing heat in Indian conditions.
Frequently Asked Questions
Why is my resin still sticky after 24 hours even though I followed the ratio?
A few things can cause this even when your ratio looks correct. First, check whether your product specifies ratio by volume or by weight — confusing the two is a very common resin mixing ratio mistake. Second, temperature plays a big role: if your room is below 22–24°C, epoxy cures much more slowly and may feel sticky at 24 hours but firm up by 48–72 hours. Third, insufficient mixing time leaves pockets of unreacted material that stay soft. Try warming the piece gently (a heat lamp or warm room) and giving it another 24 hours before deciding it is ruined.
How do I get the correct resin to hardener ratio without a digital scale?
Use a silicone graduated cup with clearly marked measurements and read the level at eye level to avoid parallax error. Measure each component in a separate cup before combining them — this way you can verify each measurement independently. For anything under 30ml, a 0.1g precision digital scale is genuinely worth the investment, as volume measurements at small quantities have proportionally larger errors. If you must go without a scale, slow down and be very deliberate about each reading.
Can I fix resin that has already cured soft and bendy?
Unfortunately, once resin has cured — even incorrectly — you cannot chemically fix it by adding more hardener on top. The uncured components are locked into the material. For shallow pours, you can sometimes sand the surface lightly and pour a fresh, correctly mixed layer on top, which may mask the problem if the underlying layer is at least partially solid. For pieces that are fully soft and flexible throughout, the batch is usually lost. Prevention through accurate measurement is the only real solution.
What is the best mixing cup for epoxy resin in India?
Silicone cups are the best choice for most resin artists. They release cured resin cleanly, the graduation marks stay readable over many uses, and the flexible walls let you squeeze out every drop without scraping. For larger pours (100ml and above), a silicone jug with a pour spout gives you better control. For small jewellery work under 50ml, small disposable graduated cups are practical and eliminate any risk of cross-contamination between sessions.
Does the type of mixing stick affect whether resin cures properly?
The mixing stick itself does not affect the chemistry, but the shape affects how thoroughly you can mix. A flat, tongue-depressor style stick reaches the bottom corners and wall edges of a cup far better than a round dowel or chopstick. Inadequate mixing — leaving unmixed streaks of resin or hardener — is a direct cause of resin not curing properly. Always mix for at least 3–4 minutes, scraping walls and bottom throughout, not just stirring in the centre.
Is it okay to reuse silicone mixing cups between sessions?
Yes, and this is one of the main advantages of silicone cups. Once the resin inside has cured fully, it peels away cleanly from the silicone surface, leaving the cup ready for the next use. Just make sure the cup is completely clean and dry before the next session — any cured flakes left inside can contaminate your fresh mix. Do not use soap and water if there is still uncured resin present; wipe with isopropyl alcohol first, then wash.
Why does my resin cure fine in summer but stay soft in winter?
Epoxy resin is very temperature-sensitive. Most standard epoxy systems need a minimum ambient temperature of around 22–24°C to cure properly within the stated timeframe. In Indian winters, especially in northern states or air-conditioned rooms, temperatures can drop below this threshold. The resin may eventually cure, but it will take much longer and may feel soft or tacky at the 24-hour mark. Warm your workspace, keep your resin bottles at room temperature before mixing, and consider extending cure time to 48–72 hours in cooler conditions.
Wrapping Up
Resin mixing ratio mistakes are almost always the result of small, compounding habits — not one big error. The cup you choose, how you read the graduation marks, whether you scrape the walls at the end of a pour, whether you measure by volume when you should be measuring by weight — each of these nudges your ratio slightly off, and slightly off is enough to leave you with resin that is soft, bendy, or permanently sticky.
The good news is that every single one of these habits is fixable. Switch to a proper silicone graduated cup, measure each component separately, mix thoroughly for the full recommended time, and stop scraping the cup at the end. These four changes alone will solve most curing problems beginners face.
If you are setting up your workspace properly, Shrebhavi has the tools to make accurate mixing straightforward — from silicone cups in the right sizes to disposable graduated cups for small batches. And if you are still troubleshooting a specific curing problem, the article on Why Your Resin Is Still Sticky After 24 Hours — and How to Fix It Before You Ruin the Piece goes into even more detail on diagnosis and recovery. For project inspiration once your mixing is dialled in, Creating Unique Monsoon Decor: A Step-by-Step Guide to Using Silicone Molds with Resin is a great next read.
Get the ratio right, and everything else about resin art becomes a lot more enjoyable.