Are all epoxy resins the same? What’s the difference?
For any artist, heading out to your local craft store isn’t just about having fun browsing products. With so many brands, qualities, and varieties to choose from, it’s also about knowing what is going to be most suitable for the project you are working on.
Epoxy resins are an increasingly popular material that more artists are using in their work. And one of the most common questions we’re asked is whether all epoxy resins are made equal, and whether it really matters if you choose one over another. So, in this post, we’re covering off which features you need to look at to make the right choice for your next project.
First of all, what is epoxy resin?
Epoxy resin is a liquid adhesive material which then hardens or cures into a solid with the help of a hardening agent. It’s strong, durable and water-resistant which makes it extremely versatile for a number of different applications.
Epoxy resin can bond with many materials such as wood, metals, some plastics and more. However, it’s also good to know what it won’t stick to such as plastics like polyethylene and polypropylene, EPDM rubber, polymers like Teflon and Tedlar, or anodized aluminium.
There are three primary categories of resin; pure, polyester and acrylate resins all have their own pros and cons when working on various projects. Pure epoxy resin cures much slower with less risk of shrinkage; polyester resin cures quickly at a lower temperature which makes it useful for quick projects or the industrial space; and acrylate resin works well with damper materials and is generally hardier which makes it suitable with plastic, paints and textiles.
But how long does epoxy resin last? Once cured, epoxy resin is very resistant to wear and tear, cracking, peeling, corrosion, and damage from chemical or environmental factors. As long as you’ve found the right type of resin for your project and treat it well, your art masterpiece will last for years to come.
How much does epoxy resin cost?
Like most art and craft materials, the cost of epoxy resin varies greatly depending on the type and quality that you choose. Generally, you can expect to spend anywhere from $50 to $120 per litre of epoxy resin. As happens with most bulk purchases, the more epoxy resin you purchase, the cheaper the ‘per litre’ price will become.
Mixing ratio, working time and hardness once dry
Most pre-packaged resins will have a guide to the mixing ratio of resin and hardener to make sure it cures properly. Most work on a 1:1 mixing ratio, though there are those that have a 2:1 or 4:1 ratio. It’s important to note that increasing the amount of hardener will not necessarily reduce the time it takes for a project to harden, or affect how hard or soft the final result will be. This will depend on the type of resin you choose to work with and the hardness of that resin type when dry.
Once mixed, you’ll only have a certain amount of time before the resin begins to gel and harden. This will depend on the type of resin and how quickly it cures but is generally somewhere between 30 to 60 minutes.
Thickness and clarity
All resin formulas have guides to assist with managing thickness depending on different viscosity manufactured and whether they require warming or setting at room temperature. We recommend sticking to these guides to ensure that your resin cures smoothly and with clarity. If you want to create thicker layers than what is recommended, do this in stages and make sure you allow the first layer to set before the second pour. This will help maintain a smooth and clear look across your entire project.
Heat-resistance and UV stability
The temperature your epoxy is going to withstand will come down to two things; the temperature it cures at, and how much heat it can withstand when hardened. Many epoxy resins aren’t actually heat-resistant which makes them vulnerable to sunlight as well as unsuitable for use with products bearing heat. We recommend an epoxy like Art Resin that has a UV resistant additive to protect from sunlight warmth and yellowing. An epoxy with a very high heat-resistance such as Ultra Cast XT will be most suitable for products such as coasters.
Using epoxy resin for timber
Epoxy resin is one of the best options for working with timber as it shrinks less and cures harder than some other resins. Wooden furniture is going to need stronger, more durable epoxy such as Dalchem Crystal Clear Resin to be firmer and more resistant to scratches.
Make sure to use wood that has been sanded and degreased, avoid using pre-treated timber, and ensure there are no loose fibres that could get mixed into the resin.
Deeper casting timber sections require deep pour resin such as the UResin Ocean Cast. This perfect for working with timber of more than 5cm deep.
Are epoxy resins toxic?
As with any product it’s important to keep safety front of mind when working with epoxy resins. Some resins are designed to be non-toxic while others might not have reached that certification.
We always recommend working in a well-ventilated room, using gloves and avoiding direct contact with hardeners and resins. It’s also good to keep an eye on the safety recommendations for the particular resin you are using to see whether safety goggles or filtered masks are also appropriate.