Silicone moulds make it possible to create candles with shapes, reliefs and finishes that cannot be achieved in a container. However, they also require better control of the wax, wick placement, sealing, pouring, cooling and demoulding.
When a candle breaks, bends, leaks wax through the wick hole or develops a sinkhole, the mould is rarely the only cause. Several process decisions are usually involved, from the hardness of the wax to the moment chosen for demoulding.
In this guide, you will learn how to make candles with silicone moulds step by step and how to prevent the most common faults without relying on universal temperatures or percentages that may not suit your wax.
What do you need to make candles with silicone moulds?
To make a moulded candle, you need a clean, dry mould, a wax suitable for freestanding candles, a compatible wick, a system for centring it, material for sealing the hole, and tools for weighing and controlling temperature.
The basic materials are:
- A candle mould in good condition.
- A wax formulated for moulded candles.
- A candle wick suited to the diameter and formula.
- A support or centring device to keep the wick straight.
- Sealing material compatible with the mould.
- Scales, thermometer, melting container and mixing utensil.
- Dye or fragrance, only when the formula supports them.
Before starting, check the technical data sheets for the wax, fragrance and any additives. Working conditions vary according to the product used.
Which wax should you choose for a silicone mould?
A demoulded candle must retain its shape without the support of a glass or container. It is therefore advisable to use a wax designed for moulded candles, with the hardness and contraction needed to form a stable piece.
A wax intended for container candles may be too soft, mark when touched, bend in narrow areas or lose details during demoulding. The choice also depends on the size of the figure, the thickness of its parts and the finish you want.
Always check:
- That the wax is intended for moulded or freestanding candles.
- Its melting and pouring ranges.
- The permitted fragrance load.
- Its compatibility with dyes and additives.
- The recommended cooling or stabilisation time.
You can compare the waxes available from Naturcera and learn more in the guide on which wax to use for each type of candle.
How should you choose and prepare the mould?
The mould should match the level of detail you want and the strength required from the finished candle. Figures with thin extremities, deep reliefs or abrupt changes in thickness are more vulnerable to breakage than compact shapes.
Before pouring the wax:
- Check that the mould has no cuts, deformation or wax residue.
- Clean it according to the manufacturer's instructions.
- Allow it to dry completely.
- Place it on a flat, stable surface.
- Add external support if the mould opens or loses its shape when filled.
- Identify where the wick will pass through and how that point will be sealed.
Do not apply release agent automatically. Many silicone moulds allow the candle to be removed without it, and an unsuitable product may alter the surface. Use it only if recommended by the mould manufacturer or the wax formulation.
How do you position the wick and prevent leaks?
The wick must be centred and tensioned before pouring. If it passes through the base of the mould, the exit point must be carefully sealed to prevent liquid wax from escaping.
The general procedure is:
- Pass the wick through the hole provided in the mould.
- Leave enough length at both ends to tension it.
- Seal the outside with material suitable for this purpose.
- Check the seal before filling the mould completely.
- Secure the upper end with a centring device or support.
- Check that the wick follows the axis of the figure without touching the walls.
In irregular moulds, the visual centre does not always match the most suitable burn path. The wick should run through the main mass of wax and must then be validated with a burn test. See also the guide on choosing candle wicks.
How can you check the seal before pouring?
Pour a small amount of wax and wait briefly before filling the mould. If a leak appears, stop, recover the wax when it is safe to do so and reseal the opening. Trying to stop a leak while the mould is full usually soils the piece and makes the loss harder to control.
How do you calculate the amount of wax?
The amount depends on the internal volume of the mould and the density of the wax. To avoid wasting material, weigh a completed test candle or record the amount used the first time and use it as a reference for future units made with the same mould.
When working with a new mould:
- Prepare slightly more wax than estimated to cover losses and corrections.
- Record the starting weight and the amount left over.
- Reserve a small amount for a possible second pour.
- Do not mix leftovers from different formulas without checking compatibility.
Repeat the measurement if you change wax, because two materials may occupy the same volume at different weights.
How do you melt, colour and fragrance the wax?
The wax must be melted and prepared within the ranges stated in its technical data sheet. Avoid applying a single temperature to every wax, because each formulation behaves differently.
Follow this working order:
- Weigh the wax, dye and fragrance separately.
- Melt the wax without keeping it at high temperatures longer than necessary.
- Add the candle dye at the stage specified for that product.
- Add the candle fragrance within the recommended range.
- Mix slowly, reaching the bottom and sides of the container.
- Record the incorporation and pouring temperatures.
An excessive fragrance load can soften the candle, make demoulding more difficult or create an unstable surface. Use only the percentage supported by the wax-and-fragrance combination.
How do you pour wax without creating bubbles or voids?
A slow, continuous pour reduces air entry and helps the wax reach the mould reliefs. Pouring from too high or striking the mould forcefully can create bubbles, splashes or wick displacement.
To improve filling:
- Keep the mould completely upright.
- Pour close to an inside wall and at a steady rate.
- Avoid repeatedly stopping the pour.
- Tap the outside gently to release trapped air without deforming the mould.
- Check that the wick remains centred.
- Reserve wax from the same mixture to correct later contraction.
If the manufacturer allows the mould to be warmed, do so evenly and under control. Do not heat it without knowing its limits or apply an intense heat source directly to the silicone.
Why does a sinkhole appear?
A sinkhole usually appears because the wax contracts as it cools. It is especially visible around the wick or in thick figures, where the centre takes longer to solidify than the surface.
To reduce it:
- Use the pouring temperature recommended for the wax.
- Avoid sudden temperature changes during cooling.
- Do not move the mould while the structure is forming.
- Reserve part of the mixture to fill the sunken area.
- When the formulation allows, make relief channels near the wick before the second pour.
- Make the correction before the difference between layers creates a visible or weak joint.
Do not refill with a different wax or improvise a correction temperature. The second pour should form part of a documented test for that wax and mould.
How long should a candle cool before demoulding?
The candle must be completely firm and cool before the mould is removed. The time varies according to size, thickness, wax, room temperature and the geometry of the figure.
A hard surface does not guarantee that the interior is stable. If you demould too soon, the piece may bend, mark under your fingers, lose detail or break under its own weight.
During cooling:
- Keep the mould on a level surface.
- Avoid draughts and direct heat sources.
- Do not press the silicone to check the inside.
- Do not accelerate the process in a refrigerator or freezer unless the technical data sheet says to do so.
- Allow large pieces more time to stabilise.
How do you demould a candle without breaking it?
To demould correctly, separate the silicone from the candle instead of pulling the candle out. Use the flexibility of the mould to release the surface progressively.
- Remove the seal and release the wick without forcing it.
- Gently separate the upper edges of the mould.
- Peel the silicone away from the wider areas.
- Move gradually towards the reliefs and narrow parts.
- Turn the mould back on itself where its design allows.
- Release fine details last while supporting the strongest part of the candle.
If the wax dents when touched or the figure bends, stop demoulding and allow it to stabilise for longer. Do not pull the wick to remove the candle.
How can you correct the most common problems?
| Problem | Likely cause | First correction |
|---|---|---|
| Wax leaks from the base | Poorly sealed wick hole or displaced mould. | Empty safely, clean and reseal before filling. |
| Bubbles or small voids appear | Trapped air, fast pouring or reliefs that are difficult to fill. | Pour more slowly and release air with gentle movements. |
| Details break | Wax is too soft, demoulding is too early or removal is abrupt. | Review the wax, extend stabilisation and peel the mould away first. |
| The candle bends | Deformed mould, insufficient support or demoulding while warm. | Stabilise the mould and wait until the candle is completely firm. |
| A sinkhole forms beside the wick | Contraction during cooling. | Apply a second pour with the same formula and a controlled process. |
| The wick moves off centre | Insufficient tension or movement during pouring. | Secure it with a centring device and check immediately after filling. |
| Lines appear between layers | The second pour was too late or at an unsuitable temperature. | Adjust the timing and temperature in the next test. |
How do you make a candle with a silicone mould step by step?
This is the complete process, which must be adapted to the instructions for your materials:
- Select the wax. Use a formula suitable for moulded candles.
- Inspect the mould. It must be clean, dry and stable.
- Position the wick. Centre it, tension it and seal the hole.
- Weigh the materials. Record every quantity.
- Melt the wax. Follow the technical data sheet.
- Add colour and fragrance. Only within the permitted ranges.
- Pour slowly. Avoid moving the wick or deforming the mould.
- Control contraction. Make a second pour if the formula requires it.
- Allow it to cool completely. Do not accelerate the process without technical guidance.
- Demould progressively. Remove the silicone from the piece and release fine details last.
How do you check that the candle is safe and repeatable?
A candle that looks good still requires a burn test. Shape, diameter, wax, fragrance and wick all affect how it burns.
Record the following in each test:
- Wax, batch and amount used.
- Mould and final candle weight.
- Wick reference and position.
- Fragrance and dye percentages.
- Mixing and pouring temperatures.
- Cooling time and demoulding date.
- Flame and melt-pool behaviour.
- Stability of the figure during burning.
Do not produce a large batch after a single unit. Repeat the formula and confirm that the result remains consistent before scaling.
Frequently asked questions about silicone candle moulds
Do silicone moulds need release agent?
Not always. Many moulds allow the candle to be removed directly. Use release agent only when recommended by the manufacturer or when a controlled test shows that it improves the result without affecting the surface.
Can soy wax be used in a mould?
Yes, provided that the specific wax is formulated for moulded candles. Soy waxes do not all have the same hardness; a container wax may not support a freestanding figure properly.
Why does the candle break when it is removed?
The most common causes are demoulding too soon, using a wax that is too soft, pulling the piece instead of peeling away the silicone, or working with very fine details without releasing them progressively.
Can a defective candle be remelted?
Some wax may be recovered if the materials are compatible and it has not been contaminated, but reheating can alter the fragrance, colour or behaviour. To diagnose the fault, it is preferable to prepare a new documented test.
When should the wick be trimmed?
Trim the wick after demoulding and stabilising the candle, leaving the appropriate length for the burn test. Do not cut it flush before checking the result.
How do you centre the wick in an irregular figure?
Find the axis of the main mass of wax, secure the wick at both ends and check its route before pouring. The final position must be validated with a burn test.
Conclusion: successful demoulding starts before pouring
Achieving a defined, straight candle without breaks depends on preparing the mould correctly, choosing suitable wax, sealing and centring the wick, controlling the pour and respecting the cooling process. Demoulding is only the final stage of a process that must remain stable from beginning to end.
At Naturcera you can find candle moulds, waxes, wicks and accessories for your tests. If you are just starting, also see the guide on everything you need to make candles at home.
