How to Remove Bubbles from Epoxy Resin (Complete Guide)

Bubbles are the number one complaint in resin art. A tiny air bubble trapped in a clear coaster or a flower block catches the eye straight away. The good news is that most bubbles can be prevented before you pour, and the rest can be removed in the first few minutes after pouring.

Why bubbles form in resin

Bubbles come from air that gets into the resin and can't escape before it thickens. The main sources are:

• Mixing too fast. Whipping the resin folds air into it.
• Cold resin. Thick, cold resin holds on to bubbles.
• Pouring from a height. The falling stream carries air with it.
• Porous surfaces. Wood, MDF and dried flowers release air as resin soaks in.
• Thick pours with the wrong resin. Coating resin poured too deep traps bubbles and heats up.

6 ways to get bubble-free resin

1. Warm the resin before mixing

In cooler weather, place the sealed bottles in a bowl of warm water for 10–15 minutes. Warm resin is thinner, so bubbles rise and pop more easily.

2. Mix slowly

Stir slowly and steadily for 3–5 minutes, keeping the stick against the bottom of the cup. Scrape the sides without lifting the stick out again and again. More in How to Mix Epoxy Resin Correctly.

3. Let it rest for a minute

After mixing, let the cup sit for a minute or two. Many bubbles rise to the top on their own. Don't wait too long, because the resin starts to thicken.

4. Pour low and slow

Pour from just above the mould in a thin, steady stream, into the centre. Let the resin spread by itself.

5. Use a heat gun or torch

Within a few minutes of pouring, pass a heat gun or small torch quickly over the surface, keeping it moving and a few centimetres away. Repeat once or twice in the first 15 minutes. Never hold the heat on one spot, because that can scorch the resin or warp the mould.

6. Seal porous surfaces first

For wood, MDF and dried flowers, brush on a thin seal coat of resin and let it set before the main pour. This stops air from escaping into your final layer.

💡 Pro tip: For deep moulds and flower blocks, use a deep pour resin like Flex 3:1 and pour in layers of up to 2 inches. Thin layers release bubbles far better than one thick pour.

What if bubbles appear after curing?

Small surface bubbles can be sanded smooth, then covered with a thin fresh coat of resin. Bubbles deep inside a cured piece can't be removed, so use them as a reminder for next time: warmer resin, slower mixing, thinner layers.

Quick bubble-free checklist

1. Warm resin in cool weather
2. Mix slowly for 3–5 minutes
3. Rest the cup briefly
4. Pour low and slow
5. Heat gun in the first 15 minutes
6. Seal wood and flowers first

👉 Shop bubble-free resin kits

FAQs

Can I use a hair dryer to remove resin bubbles?

A hair dryer blows air and dust onto the surface and isn't hot enough. A heat gun or small torch works much better.

Why do bubbles keep coming up from my wooden board?

Wood has tiny air pockets. Seal it with a thin coat of resin first and let it set before the main pour.

How long can I keep removing bubbles?

Mostly in the first 15–20 minutes, before the resin starts to thicken.