Epoxy resin art for beginners: supplies, mixing ratios and room temperature

TUREFF• •0

Epoxy resin art covers everything from glossy coasters and jewellery to ocean-style paintings and river tables. The basic idea is simple: two liquids, a resin and a hardener, are mixed together and react to form a hard, clear plastic. Getting good results comes down to three things: the right product for the job, accurate mixing, and a warm, clean workspace.

Choosing the right type of epoxy

Epoxies are formulated for different jobs, and using the wrong one is a common beginner mistake.

Coating or art resin: thicker, designed to be poured in thin layers over paintings, boards and coasters. It usually cures in roughly a day and should not be poured deep.
Casting or deep pour resin: thinner, designed to be poured into moulds in thicker layers. It cures more slowly, which lets heat escape.

Each product has a maximum pour depth on its data sheet. Pouring deeper than that can make it overheat, crack, yellow or even smoke.

Basic supplies

Resin and hardener (from the same product line; never mix brands).
Graduated mixing cups or digital scales, depending on the product.
Flat stirring sticks or silicone spatulas.
Nitrile gloves, safety glasses and protective clothing.
Silicone moulds, or a sealed, taped substrate for pours.
A level surface and a spirit level.
Plastic sheeting or silicone mats to protect your table.
A cover, such as a large box, to keep dust off while it cures.
A heat gun or small torch for surface bubbles.
Paper towels and isopropyl alcohol for cleaning tools (not skin).

Mixing ratios: volume or weight?

Every epoxy has a fixed mix ratio set by the manufacturer, such as 1:1 or 2:1. Follow the manufacturer's instructions exactly. The crucial detail is whether that ratio is by volume or by weight. The resin and hardener usually have different densities, so a ratio by volume does not give the same amounts as the same ratio by weight. If the label says 1:1 by volume, measure equal volumes in graduated cups; weighing out equal grams will put you off ratio. If the label gives a ratio by weight, use digital scales. Some manufacturers give both. Getting the ratio wrong is one of the main reasons resin stays sticky. Adding extra hardener does not make it cure faster or harder; it just leaves uncured material behind.

How to mix

Measure each part accurately in a clean cup.
Combine and stir slowly and steadily for the full time the manufacturer recommends, often several minutes.
Scrape the sides and bottom of the cup repeatedly, as unmixed resin clings there.
Many artists then pour into a second clean cup and mix again briefly, leaving the unmixed film in the first.
Add colour once the resin is fully mixed.

Mixed resin has a limited working time (pot life). Mixing a larger batch in a deep cup makes it heat up and set faster, so mix only what you can use.

Workspace temperature

Epoxy is very sensitive to temperature. Most art resins work best in a warm room, with many manufacturers recommending somewhere in the low to mid twenties Celsius, and they want that temperature kept steady through the cure. Check the data sheet for your product.

Too cold: resin turns thick and hard to mix, traps tiny bubbles that look cloudy, and cures slowly or incompletely.
Too hot: working time shortens and the resin can set before you are finished.
Humidity: damp air can leave a hazy or greasy surface on some epoxies.

If the resin is cold, stand the tightly closed bottles in a warm (not boiling) water bath for a few minutes, then dry them thoroughly; even a drop of water in the mix can cause cloudiness. Never microwave resin.

Safety first

Work in a well-ventilated room, wear nitrile gloves, keep resin off your skin, and keep children and pets away. Read the safety guide in this room before your first pour. What was your first resin project, and what would you do differently? Share your questions in the comments.