Epoxy vs Polyester Clear Casting Resin: Which Should You Choose?

Eco-Resin Featured Image

It’s time to start your next (or first) resin project—but with so many options available, choosing the right clear casting resin can feel overwhelming.

Should you go for epoxy resin or polyester resin?

In this guide, we break down the key differences, benefits, and drawbacks of each—helping you choose the best casting resin for your project with confidence.

How to Choose the Right Casting Resin

Before deciding between epoxy and polyester, ask yourself:

  • Durability – Will your piece face heavy use (e.g. tables)?
  • Finishing effort – Are you happy to sand and polish?
  • Budget – Are you working to a tight cost?
  • Odour sensitivity – Will you be working indoors?

Your answers will quickly point you in the right direction.

Polyester Water Clear Casting Resin: Pros & Cons

Key Benefits

UV Stable Clear Finish

Polyester casting resin cures crystal clear and remains UV stable, making it ideal for:

  • Outdoor features
  • Decorative castings
  • Water features

Excellent for Pigments & Small Projects

Perfect for:

  • Jewellery
  • Paperweights
  • Decorative embeds

You can add polyester pigments to achieve unique colours and effects.

Cost-Effective Option

Polyester resin is significantly cheaper than epoxy, making it ideal for budget-conscious projects.

Things to Consider

Strong odour

Polyester resin has a strong smell (styrene) and must be used in a well-ventilated area.

Mixing Requires Precision

  • Catalyst must be added carefully (recommended max: 1.5%)
  • Too much = faster cure + yellowing
  • Approx. 20-minute working time

Top tip: Use digital scales or a catalyst dispenser for accuracy.

Limited Pour Depth

  • Maximum 10mm per layer
  • Must allow each layer to cool before pouring the next

Finishing Required

Polyester resin cures with a slightly rippled surface. To achieve a glass-like finish:

  • Wet sand
  • Polish with compound (e.g. Farecla)

Lower Durability

Suitable for light or occasional use surfaces, but not recommended for:

  • Dining tables
  • High-traffic furniture

Epoxy Clear Casting Resin: Pros & Cons

Key Benefits

Extremely Durable

Epoxy resin is highly resistant to scratches and wear, making it perfect for:

  • River tables
  • Bar tops
  • Work surfaces

Easy Mixig Ratios

Typically mixed at:

  • 1:1 or 2:1 ratios

This is much simpler and reduces the risk of error compared to polyester systems.

Low Odour

Much more user-friendly, especially for indoor projects.

No Finishing Required

Cures with a smooth, glossy surface, eliminating the need for sanding or polishing.

Versatile Pigment Options

Compatible with:

  • Metallic pigments
  • Translucent colours
  • Solid tones

Things to Consider

Higher Cost

Epoxy is a premium product with a higher price point.

Longer Cure Time

  • Can take up to 72 hours for full cure
  • Slower turnaround compared to polyester

 

Quick Comparison: Epoxy vs Polyester Resin

Feature
Polyester Resin
Epoxy Resin
Cost
Budget Friendly
Higher Cost
Durability
Moderate
Very high
Odour
Strong
Low
Ease of mixing
Precision Needed
Simple ratios
Finish
Requires polishing
Ready-to-use glossy finish
Pour Depth
~10mm layers
Deeper pours possible
Best For
Small decorative items
Tables, surfaces, heavy use

Which Casting Resin should you Choose?

Choose Polyester Resin if you:

  • Are working on small decorative projects
  • Need a budget-friendly option
  • Don’t mind sanding and polishing

 

Choose Epoxy Resin if you:

  • Need durability for everyday use
  • Are making tables or bar tops
  • Want a low-odour, easy-to-use system
  • Prefer a ready-to-finish surface

 

Final Thoughts

Both epoxy and polyester clear casting resins have their place—it all comes down to your specific project and priorities.

If you’re creating jewellery or decorative pieces, polyester resin is a great value option.
For long-lasting, high-performance surfaces, epoxy is the clear winner.

Need Help Choosing?

Still unsure which clear casting resin is right for you?

Get in touch with the Tricel Composites team for expert advice—we’re happy to help you find the perfect solution.

Order Clear Casting Resin Today

Read More...

  • Follow Composites on LinkedIn
Linkedin