Resin Problems Solved: Bubbles, Sticky, Cloudy and More

Posted by

Haanz Team

2026-10-18

On 2026-10-18

Haanz Art GuideFree, practical advice from the team at Haanz Art & Craft Materials

Every resin maker runs into trouble sometimes. The good news is that most resin problems have a simple cause, and once you know it, they are easy to prevent. This guide covers the most common issues with epoxy and UV resin: bubbles, sticky or soft pieces, cloudiness, yellowing and more.

Resin problems: start with the basics

Most problems come back to four things: measuring, mixing, moisture and temperature. Before anything else, check that you followed the resin label exactly, mixed thoroughly, used dry tools and moulds, and worked in a suitable room.

Resin bubbles

Causes: stirring too fast, pouring from high up, air escaping from porous inclusions such as flowers or paper, and cold resin, which is thicker.

Stir slowly and steadily, scraping the sides.
Let the mixed resin rest for a minute or two so bubbles can rise.
Pour slowly, close to the mould.
Seal flowers and paper with a thin coat first.
Pop surface bubbles with a toothpick, or pass a heat gun such as the Electric Heat Gun 300W briefly over epoxy, keeping it moving and at a distance.

Sticky resin or soft spots

Epoxy causes: wrong ratio, not mixed long enough, unmixed resin scraped from the cup sides, or a very cold room.

UV resin causes: layers poured too thick, not enough curing time, or parts the light could not reach.

Measure exactly with clear marked cups such as the Epoxy Mixing Cup, and mix for the time on the label.
Avoid scraping the last bit from the cup into the mould.
For UV resin, pour thin layers and cure each side under a lamp like the 15W desktop UV light.
A slightly tacky epoxy surface may firm up with more time in a warm room. If it stays sticky, a fresh, correctly mixed coat on top can help.

Cloudy or milky resin

Causes: moisture from damp moulds, flowers or humid air, or very cold conditions.

Make sure moulds, tools and inclusions are completely dry.
Avoid working on very humid, rainy days, or use a dry room.
Store resin bottles tightly closed.

Other common issues

Yellowing: strong sunlight and age can yellow resin over time. Keep finished pieces out of direct sun.
Dents or shrinking at the surface: add a thin top-up layer once cured.
Overheating or cracking: pouring too thick in one go. Pour in layers, following the maximum depth on the label.
Uneven colour: pigment not fully mixed. Mix colour into a small amount first, then add it.
Dust and hairs: cover pieces with a clean box while curing.
Sharp edges: fill moulds to just below the rim.

Prices change, so see each product page for today’s price. If you are just beginning, our resin art for beginners guide and UV lamp guide cover the basics.

Problems with moulds

Piece will not come out: it may not be fully cured. Wait longer before demoulding, then flex the silicone gently.
Dull surface: the mould surface may be scratched or dirty. Wash moulds with mild soap and water and store them flat.
Resin leaking from frames: press UV Tape firmly onto open-back frames before pouring.

A quick checklist before every pour

Read the resin label for ratio, mixing time and maximum depth.
Level, clean, dust-free table.
Dry moulds, tools and inclusions.
Gloves on, room ventilated.
Everything ready before you mix.

Frequently asked questions

Can I fix bubbles after resin has cured?

Not inside the piece. You can sand the surface lightly and add a thin clear coat to fill surface pits.

Why did my resin get hot?

Epoxy gives off heat as it cures. Large, thick pours get hotter, so pour in layers as the label directs.

Is humidity a problem in Sri Lanka?

It can be. Work in a dry room, keep everything dry, and close resin bottles tightly.

Do you deliver islandwide?

Yes. We deliver across Sri Lanka in 2–5 working days, with cash on delivery, card or bank transfer. You can also visit our shops in Boralesgamuwa and Horana, open every day from 9 AM to 6 PM.

Not sure what to choose? WhatsApp the Haanz team on 0711 515 515 and we’ll help you solve a resin problem.

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