Ensuring the correct amount of catalyst (hardener) is added to your resin mix is vital for achieving a strong, flawless, and safe cure on every project. This guide is designed for crafters, artists, makers, and DIY enthusiasts looking to understand how much catalyst is needed for different types of epoxy resin—so you can confidently mix, cast, and create, whether you’re working on jewellery, tables, composite coatings, or model building.

Resin Mixing Ratios Explained: Catalyst Amounts Compared

Resin systems require a precise balance of resin (component A) and catalyst or hardener (component B). The correct proportion depends on the specific resin formulation. Some resins are mixed by volume—such as 1:1 by volume mixing—where equal parts are simply combined. Others use ratios by volume or by weight, such as 2:1 mixing ratio (two parts resin to one part hardener), 4:1 mixing ratio (four parts resin to one part hardener), or exact weight-based measurements like 100:55 mixing by weight. Choosing the right approach ensures that your resin cures without remaining sticky, brittle, or producing unwanted bubbles. Each system suits different applications and project types, as detailed below.

Visual Comparison of Resin Mixing Techniques

See how different resin systems require specific mixing ratios for optimal results: from 1:1 by volume mixing in beginner-friendly crafts to 100:55 by weight for advanced composite work. Consistent, thorough mixing is the key to durable and beautiful finishes—no matter the ratio!

Simple 1:1 by Volume – “One-2-One” Epoxy Resin for Handcraft

If you’re just starting out, or you prefer an error-proof system, “One-2-One” – Epoxy Resin for Handcraft, 1:1 Mixing Ratio is tailored for you. This resin is mixed in 1:1 by volume mixing: just combine equal volumes of resin and hardener. No scales are needed—simply measure out the same amount of each part. This simplicity makes it especially popular among jewellery makers and decorative artisans looking for an easy, reliable cure and a glossy, crystal-clear finish. Plus, its non-toxic formulation and UV filters ensure long-lasting, safe results for both beginners and experienced crafters.

Fast Results with a 2:1 Mixing Ratio – “ICreation” Fast Epoxy Resin

For time-sensitive projects requiring a swift turnaround, “ICreation” – Fast Epoxy Resin, 6h Demoulding, Transparent Gloss Finish is the answer. This resin uses a 2:1 mixing ratio—two parts resin to one part hardener—providing a rapid catalysis that lets you demould after roughly 6 hours. This is ideal for those producing multiple pieces or working under time constraints, such as craft fairs or commission work. The self-levelling, clear-gloss finish is perfect for both professional and hobby craft applications.

Precision with 100:55 Mixing by Weight – “Carbon Resin” for Fibre Coatings

When working with carbon fibre, fibreglass, or technical composites, accuracy in mixing becomes critical. The “Carbon Resin” – Epoxy Resin for Carbon Fiber & Fiberglass Coating requires 100:55 mixing by weight: weigh out 100 parts resin to 55 parts hardener. This precise approach ensures proper fabric impregnation, bubble minimisation, and ultimate structural strength—making it a staple among composite technicians, model builders, and those seeking high mechanical performance from their cured resins.

For Deep Pours – 4:1 Mixing with “Epoxytable 10-Ten”

Tables, river projects, and large castings need a system optimised for deep pours and long working times. “Epoxytable 10-Ten” – Deep Pour Epoxy Resin for Tables, Up to 10cm Casting is engineered for just this. Its 4:1 mixing ratio (by volume) allows for up to 10cm thick pours without overheating or excessive bubbling. This formulation is the top choice for large artistic creations, river tables, and deep decorative pieces requiring a non-yellowing, perfectly clear finish that will last for years.

Choosing and Measuring Catalyst: Practical Tips

Always measure carefully—never guess catalyst quantities, as under- or over-catalysing leads to improper curing, sticky surfaces, or weakened results. Use the correct tools for each resin system: a graduated jug for volume-based mixes, or reliable digital scales for weight-based combinations. Follow manufacturer guidelines—they exist for a reason! If using a new product, double-check instructions as ratios may differ even between similar types. Keeping your workspace at a stable room temperature and mixing thoroughly will further reduce problems, particularly in large or complex pours.

Top Tips for Accurate Resin and Catalyst Mixing

Measure resin and hardener in accordance with the specified ratio, whether it’s 2:1 mixing ratio, 4:1 mixing ratio, or another formula. Scrape the sides and base of your container while mixing to ensure a uniform cure throughout your project.