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My Reward PointsThere is a common phenomenon when a candle's wax breaks and shrinks, primarily when the wax works with intricate moulds. This occurs twice during a candle's life cycle, during the making process and while burning.
These issues can degrade the candle's appearance and quality. To prevent and address these issues, it's essential to understand candle shrinkage, its causes, prevention methods, and why wax shrinks when it cools.
What Is Candle Shrinkage?
You can find candle wax shrinkage because of the natural contraction of wax as it cools and solidifies after melting. This might cause gaps or sinkholes between the candle and the mould, which affects the candle's appearance. Furthermore, candles shrink as they burn, with the wax vaporising and burning, resulting in a smaller candle over time.
In other words, the wax cooling and solidification can make it contract. Such shrinkage is a natural process; however, excessive shrinking might cause gaps between the candle and the mould, compromising the final appearance.
What Are The Causes Of Shrinking Candle?
A shrinking candle happens due to various circumstances, including cooling and solidification, wax type, pouring temperature, container material, additive ratio, and single pour. These elements are briefly explained as follows:
1. Cooling & Solidification.
Cooling and solidifying wax in candles can cause shrinkage, sinkholes, gaps, and cracks as it contracts and loses volume, causing the wax to recede from the container walls or wick.
2. Wax Type
A candle's shrinkage is greatly influenced by the type of wax used; soy wax shrinks more than paraffin or beeswax, and tougher paraffin wax can result in sinkholes in candles.
3. Pouring Temperature
When you pour wax at a high temperature, you can find candle shrinkage, the formation of sinkholes, or other related issues. The wax of a candle swells when heated and contracts as it cools, compressing more dramatically and causing gaps and flaws.
4. Container Material
The material of the container can cause candle shrinkage, especially if it is not heat-resistant or there is a significant temperature difference between the wax's molten and solid states.
5. Additive Ratio
The "additive ratio" in candlemaking refers to the proportion of additives used for wax weight, with more additives like microwaxes and modified waxes causing shrinkage and stearic acid increasing wax hardness.
6. Single Pour
When the candle wax is poured in a single layer, it can shrink and often lead to sinkholes because of uneven or rapid cooling, which creates a depression or hole in the centre.
How To Prevent Candle Shrinkage?
To prevent a shrinking candle, use high-quality wax, let the wax cool naturally, pour it a second time, manage the pouring temperature, and use additives like stearic acid or Vybar.
1. Use Good-Quality Wax.
Selecting the right wax type is crucial for precise moulds, as shrinkage rates vary depending on the type, such as soy wax, which tends to shrink more than paraffin or beeswax.
2. Let Wax Cool Naturally.
Allow the candle to cool gradually. Rapid cooling might cause the wax to flex unevenly and form cracks. Consider cooling the candle in a draft-free area or on a cooling rack.
3. Pour Twice
Don't just stop with only a single pour of wax. A second pour of heated wax can prevent candle shrinkage by filling in gaps and creating a smoother, flatter surface after the wax solidifies.
4. Control Pouring Temperature.
To prevent candle shrinkage, you can control the pouring temperature. By using a pouring temperature chart, you can tailor to your wax type to ensure you're working within the ideal temperature range.
5. Use Additives Like Stearic Acid or Vybar.
Certain wax additives, such as Vybar and stearic acid, can enhance the consistency and stability of your candles, hence lowering the likelihood that they will fracture or shrink significantly.
Why Does Wax Shrink When It Cools?
So why does candle wax shrink when it cools? Wax shrinks as it cools due to the loss of kinetic energy and the contraction of molecules. This method is caused by the phase transition, which turns wax into a liquid when heated. As it cools, it returns to a solid form, with the molecules becoming more tightly packed.
This shrinkage reduces the wax's volume, impacting candlemaking, which can cause sinkholes and gaps between the candle and the container. To prevent shrinkage, moderate cooling and temperature changes are recommended. Other factors that can affect shrinkage include the type of wax used, the pouring temperature, and the size/shape of the candle container.
Conclusion
Finally, you would probably know why does candle wax shrinks. For candles to remain high-quality and attractive, it is essential to comprehend the causes of candle wax shrinkage and how to prevent it. Candlemakers can dramatically reduce shrinkage and improve the overall integrity of their works by carefully selecting wax varieties, controlling pouring temperatures, and using procedures such as second pours.
FAQs
Q. Why does candle wax shrink after drying?
Ans. Heat expands wax, filling the container when melted. It returns to its solid state when it cools or dries, shrinking and speeding up along the edges and around the wick.
Q. Is wax shrinking common in candle making?
Ans. Candle wax shrinkage is a common issue in candlemaking, particularly with paraffin wax, where it contracts, creating depressions around the wick and candle container edges and potentially causing fissures.
Q. Which candle wax shrinks the most?
Ans. Paraffin wax, especially the harder varieties, shrinks significantly; in contrast, soy wax is less prone to shrinkage but can still shrink under specific conditions, whereas beeswax has a low shrinkage rate.
Q. Does the room temperature affect shrinkage?
Ans. Room temperature significantly influences shrinking candles, with cooler temperatures potentially causing rapid wax cooling and more pronounced shrinking, particularly when hot wax is poured.
Q. Are sinkholes and candle shrinkage the same phenomenon?
Ans. Candle sinkholes and candle shrinkage are the same thing. When molten wax cools and solidifies, it contracts, forming a dip or pit, commonly near the wick, known as a sinkhole or shrinkage.
