top of page

5 useful tips on how to mix epoxy resin and hardener correctly to avoid air bubbles!

In this post I will be talking about Epoxy resin that comes in two parts: a resin and a hardener. Mixing the resin and hardener together prompts a chemical reaction between the two allowing to transform from a liquid into a solid. Measuring accurately and mixing thoroughly is essential to making sure your epoxy resin cures properly.

Before you start working with resin, make sure you read thoroughly technical sheet that comes with your resin. Every resin is different and it needs different approach.

Full video on mixing the two is available on my YouTube channel.

1. Mixing ratio

Never assume it's 1:1, always read the technical sheet to make sure you get it right. The ratio can be either by volume or by weight. If your mixing is by volume it means it's the amount of resin that you need to pour into your plastic container. Whilst if your mixing ratio is by weight you're going to need a very accurate scale to weight required amount of resin. Volumes you're mixing will indicate what kind of scale you're going to need.

2. Temperature

Mixing epoxy requires ambient temperature that will allow it to cure correctly. In most cases this is between 20 to 25 degrees Celsius. If the temperature is too low, the epoxy might not cure and if it's too hot reaction might be sped up too much and the casting might come out with some cracks and again it might not cure correctly.

3. Humidity

Some of the resins for example polyurethane resins are not very good with the moisture. The higher humidity, the higher chance it will not cure correctly. Hence, it is important to select the right resin for the environment you're working in.

4. Plastic containers

Choose a plastic container with a flat bottom to make sure you're not missing out on any resin and to make sure resin will not be hidden in any of the notches of the container itself. When mixing, be sure to scrape the sides, corners, and bottom of the container several times during mixing. This will ensure that all the hardener is thoroughly mixed with the epoxy and should prevent the resin from having an improper cure.

5. Popsicle sticks

In all my resin projects I have used round ended wooden popsicle sticks for mixing resin. Some people might say they not great choice for mixing resin as they will introduce additional amount of air into your resin but personally I haven't notice any difference between the plastic and wooden sticks. What matters is the shape of your popsicle stick - make sure it's round ended for easier access to resin in all edges of your plastic container.

To check out how I mix my resin please follow this link to my YouTube video!

Recent Posts

See All


bottom of page