It’s time to start casting your next (or first) resin project. With a variety of different casting resins on the market, how can you be sure you are choosing the right one? How can you be sure if you require a Polyester or Epoxy resin? In this article, we break down some of the most popular uses, benefits and downsides to each casting resin available on FibreGlassDirect. We hope this information will give you a deeper insight into each product before making your final purchasing decision.

There are several things to consider when it comes to choosing the correct casting resin for your project.

  • How durable do you need your finished piece to be?
  • How much work are you willing to do at the end? e.g. compounding and sanding
  • How much are you willing to spend?
  • Do you have a dislike of strong odours?

Polyester Water Clear Casting Resin

UV Stable? Yes

The Polyester Water Clear Casting Resin sold by FibreGlassDirect is clear when poured and clear when cured. The Polyester Casting Resin is UV stable which makes it suitable for pieces to be stored outside e.g. water features or outdoor tables.

Pigment addition capabilities? Yes

This resin is great for costume jewellery and casting decorative items such as paperweights. It can be pigmented with a polyester pigment to create a wide range of different finishes that are completely unique.

Easy to mix catalyst? Yes, with care

As it is a polyester resin, the catalyst needs to be added before the resin will cure. Great care needs to be taken with the amount of catalyst addition mixed into the resin. Too much catalyst will result in a really fast cure and may also give the resin a yellow tint, affecting the water clear finish which makes this resin so popular. We would recommend no more than 1.5% which gives a working time of 20 minutes at room temperature.

A measuring cup, digital weighing scales, syringe or catalyst dispenser will help to ensure your mix ratios are on point.

It can be cast in depths of 10mm at a time. If doing multiple pours, great care should be taken in between each pour. The heat generated from each catalyst mix will rise to the surface as the resin cures ad styrene evaporates. A touch test should be taken to ensure the previous layer is adequately cool before pouring the next.

Strong odour? Yes

The Polyester Water Clear Casting Resin does have a very strong odour. For this reason and in the interest of Health and Safety, we would always recommend using this resin in a well-ventilated area.

Durability & Maintenance? Will scuff with heavy use

One of the most popular questions we get asked when it comes to the Polyester Casting Resin is ‘Can it be used for tables?’.  We have used this resin to make a penny table which turned out really well. We would, however, recommend that if you are planning on using this resin for a table, it should only be used on a table that is for occasional use. For River Resin Tables, we would definitely recommend Epoxy.

Budget-Friendly? Yes

Polyester Resin is considerably cheaper than its Epoxy counterpart. For this reason, if you are on a budget, Polyester may be the way to go – particularly for smaller casts.

Finishing Required after Curing? Yes

As the Water Clear Casting Polyester Resin cures, the surface will have a ‘rippled’ appearance. This isn’t anything to be worried about, this is the finished look for this particular type of resin. It can be sanded and compounded to remove this look and brought up to a high-shine, smooth look. Wet and Dry Sandpaper, Farecla Compound and some old-fashioned elbow grease will have this sorted in no time.

Clear Cast Epoxy Resin

UV Stable? Yes

The Clear Cast Epoxy Resin is indeed UV stable. Similar to its Polyester counterpart, the Clear Cast Epoxy Resin can be used for outdoor projects such as water features, outdoor bar tops and tables.

Pigment addition capabilities? Yes

Yes, translucent, metal and solid pigments can be mixed into the Clear Cast Epoxy Resin. 

Easy to mix? Yes

The Epoxy Resins for casting supplied by FibreGlassDirect are mixed in ratio parts e.g. 1:1 or 2:1. Many find this easier than mixing the smaller ratios of Polyester Resins and Metox Catalysts which, as detailed above, are much smaller in quantity. There is an increased chance for error with regards to mixing too much or too little. It is worth noting however that the Clear Cast Epoxy will take a lot longer to cure than the Polyester version, it can take up to 3 days for a full cure.

Strong odour? No

The Epoxy Casting Resins are far less 'smelly' than Polyester versions. This is one of the more appealing attributes of the Epoxy Resins.

Durability & Maintenance? Very durable

The Clear Cast Epoxy Resin is extremely durable and perfect for River Resin Tables and Bar Tops. It is resistant to scuffs and scratches which makes it more suitable for daily wear and tear.

Budget-Friendly? More expensive than Polyester

Epoxy is significantly more expensive than the Polyester Clear Casting Resin. As it is a more advanced Resin, this comes with a more expensive price tag. 

Finishing Required after Curing? No

Once the Clear Cast Epoxy has cured, it will be hard and smooth to the touch. There is no need for compounding. 

Which Casting Resin should you Choose?

After all the pros and cons of each resin have been weighed up, it is really down to the project at hand and often personal preference. The Epoxy Resin may be overkill for some projects e.g. costume jewellery or embedding decorative items but will last the test of time with a dining table. 

If you need further assistance in choosing the right Casting Resin, don't hesitate to contact our team and we will do our best to guide you in the right direction!

Happy Casting!