Carbon Resin Mixing Ratio Guide for Fibreglass & Carbon Fibre

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Achieving durable results with carbon fibre and fibreglass projects relies on using the correct mix of resin and hardener. Here’s how to get the best from Carbon Resin for your composite work.

Recommended Mixing Ratio

To ensure Carbon Resin cures properly and delivers the strength required for composite applications, mix 100 parts resin to 55 parts hardener by weight. This precise ratio is crucial for structural integrity and optimal bonding to fibres.

Always use scales for accuracy. Inaccurate measuring can affect the final strength and curing quality.

Tips for Mixing and Application

Begin by weighing the resin and hardener separately. Combine them in a clean container and mix thoroughly for several minutes, scraping the sides and base to ensure even blending. Applying the mixture straight away helps maximise work time and performance.

Work at room temperature for best results.
Use a brush or roller for fabric impregnation to prevent bubbles and ensure even coverage.

For more details, see our Carbon Resin product page.

When This Matters

Maintaining the proper mixing ratio is especially important when strength, clarity, or resistance to impact is needed — for example in automotive or sporting goods, model building, or any technical laminating project.

Related guides

How Much Hardener Should Be Used With Penetrating Resin

Mastering the correct Carbon Resin mix delivers professional-quality, long-lasting composite results. For more on hardener ratios and resin mixing, visit our main FAQ hub on hardener use in penetrating resins.