Concrete Art Looks Cute Until the Bubbles Show Up 🫧😭

One of the most common concerns we hear from beginners is:

“My piece has a few bubbles. Did I do something wrong?” 🧐

The answer is usually no.

Before we begin, here’s a little secret: a few tiny bubbles are completely normal. In fact, if every handmade concrete piece looked absolutely identical, where would the fun be? 😉

Concrete is a natural material, and every piece develops its own personality along the way. Small pinholes and minor surface variations are often part of the handmade charm and do not affect the beauty or functionality of your creation.

✨ Think of them as freckles, not flaws.

However, excessive bubbles, larger air pockets, or clusters of holes can impact the overall finish and make a piece appear less refined. So let’s understand why they happen and how to keep them under control.

Why Do Bubbles Appear in Concrete Pieces?

1. Air Gets Trapped During Mixing 🌪️

When concrete powder and water are combined, air naturally gets mixed in too. Stirring too vigorously can introduce even more air, which later shows up as bubbles on your finished piece.

How to prevent it:
Mix slowly and consistently. Your concrete isn’t a cake batter…it doesn’t need enthusiastic whisking. 🥣

2. The Mixture Is Too Thick 🍪

A very thick concrete mixture can trap air pockets, making it difficult for them to escape before the concrete starts setting.

How to prevent it:
Follow the recommended ratio and aim for a smooth, pourable consistency. Think pancake batter, not cookie dough. 🤤

3. The Mould Was Not Tapped After Pouring 👋

One of the biggest reasons for bubbles is trapped air remaining inside the mould. Once poured, the concrete needs a little encouragement to let those bubbles escape.

How to prevent it:
Give your mould a few gentle taps on the table. Consider it a mini wake-up call for the trapped air. 🫨

4. Intricate Mould Designs🍥

Corners, patterns, textures, and deeper moulds are beautiful—but they’re also excellent hiding spots for air bubbles.

How to prevent it:
Pour carefully and use a wooden stick or silicone tool to guide the mixture into tricky corners where air likes to hide.

5. Pouring Too Quickly ⚡

Pouring everything in one go can trap air, especially around edges and detailed sections.

How to prevent it:
Slow and steady wins the race here. 🐢 A careful pour usually means fewer surprises after demoulding.

How to Fix Bubbles in Finished Pieces 🔧

Even experienced makers encounter bubbles from time to time. Don’t worry…most of them are easy to fix.

For Small Surface Holes

Create a thin slurry using the same concrete mix and gently fill the holes.

✨ A quick touch-up can make a huge difference.

For Larger Voids

Fill the area with fresh concrete paste and allow it to cure completely before proceeding with finishing.

When to Leave Them As They Are 🤍

If your piece has only a few tiny bubbles or pinholes, there is often no need to repair them at all.

Sometimes we spend more time noticing imperfections than anyone else ever will. A few tiny bubbles are often part of what makes handmade pieces feel authentic and unique.

Tips to Minimise Bubbles 💡

✓ Mix gently rather than aggressively.

✓ Follow the recommended water ratio.

✓ Pour slowly and evenly.

✓ Tap the mould after pouring.

✓ Pay extra attention to corners and detailed areas.

✓ Allow the piece to cure properly before demoulding.

Final Thoughts ✨

Bubbles are a natural part of working with concrete and something every maker encounters, whether they’re creating their first coaster or their hundredth tray.

The goal isn’t necessarily to achieve a perfectly flawless surface every single time. A few tiny bubbles are often part of what gives handmade concrete pieces their character.

After all, handmade isn’t about perfection…it’s about creating something beautiful with your own hands. 🤍

And if a tiny bubble sneaks in here and there? Consider it proof that a real human made it. 😉

Want to Try It Without Wasting Half Your Materials?

If concrete art has been sitting on your “one day I’ll try this” list, our Concrete Art with Candle Making Masterclass is a good place to start.

We keep it beginner-friendly, practical and very real. You learn the small details that help your piece look clean, sturdy and gift-worthy, without having to guess your way through every mistake alone.

You bring the curiosity.
We will handle the bubble drama. 🫧