What is the Right Mixing Ratio for Resin & Hardener?

Q: When Getting Ratios Right Is Crucial

Large Pours: Deep casting and large projects are less forgiving of ratio errors, leading to uneven curing or wasted materials. Fine Crafting: Precision in smaller batches is important for casting jewellery or detailed pieces, as even small inconsistencies can cause cloudiness or softness. Beginner Projects: Following the specified mixing ratio helps beginners achieve consistent, repeatable results on every project.

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Getting the resin to hardener ratio right is a crucial step for any epoxy project. Proper proportioning ensures your resin cures thoroughly and delivers the expected performance and finish.

Why Mixing Ratio Matters

The correct balance of resin and hardener triggers the chemical reaction that causes epoxy to cure. Mixing too much or too little hardener can result in tacky surfaces, incomplete curing or even a compromised structure. Most epoxy resins specify a ratio such as 2:1, 100:50, or 100:55 (resin to hardener by weight or volume). However, ratios can vary between products, so always check the guidelines provided with your chosen resin.

How to Measure Accurately

Careful measuring is essential for reliable results. It’s best to use digital scales for resin systems specifying ratios by weight, ensuring precision down to the gram. If your product uses a volume ratio, choose a graduated measuring cup with clear markings. Start by weighing or measuring the resin first, then add the hardener according to the required ratio, and combine them thoroughly.

When Getting Ratios Right Is Crucial

Large Pours: Deep casting and large projects are less forgiving of ratio errors, leading to uneven curing or wasted materials.
Fine Crafting: Precision in smaller batches is important for casting jewellery or detailed pieces, as even small inconsistencies can cause cloudiness or softness.
Beginner Projects: Following the specified mixing ratio helps beginners achieve consistent, repeatable results on every project.

Related guides

How To Calculate How Much Resin Is Needed

Always double-check the recommended mixing ratio on your particular resin’s label. A precise mix leads to better results, and using the right tools helps you get it right every time. For more tips on working out exact resin amounts for your projects, see our main guide on calculating how much resin is needed.