Why did my candle crack again? This is probably one of the most common, frustrating, and frustrating questions. What seems like a simple candle crack actually involves many factors, including raw materials, temperature, molds, cooling rate, and humidity. If you want your finished candle to have a smooth surface and delicate texture, you must start with the most basic core ingredient Fully Refined Paraffin Wax. Junda Wax, from the perspective of a professional candle manufacturer, discusses why candles crack, how to prevent cracking, and how to produce stable and beautiful finished candles through more professional material formulas and production processes. We'll also briefly introduce how Junda Wax provides global customers with a one-stop supply chain service, from paraffin raw materials to wax threads, dyes, molds, and machinery, so you no longer have to worry about material issues when making candles.
I. What are the main raw materials for candles?
Although there are now more and more choices of candle materials, with beeswax, coconut wax, beeswax, and palm wax all being popular, paraffin wax remains the best choice for the candle industry in terms of global supply stability, cost control, and applicability. Among paraffin waxes, Fully Refined Paraffin Wax is the most popular. Fully Refined Paraffin Wax is white in color, has few impurities, a clean odor, and a wide melting point range, making it suitable for both container candles and molded candles.
Junda Wax exports large quantities of Fully Refined Paraffin Wax to Vietnam, Malaysia, the Philippines, the Middle East, Europe, Africa, and many other countries every year. Some customer orders even include several tons of paraffin wax, wax production lines, dyes, and molds. They often tell us, "Buying everything from you in one stop is so convenient; it's much better than sourcing from several suppliers." This is why paraffin wax has always held an irreplaceable position in the candle industry, especially high-purity raw materials like Fully Refined Paraffin Wax, which are a staple in the inventory of professional candle factories.
II. What is Fully Refined Paraffin Wax?
The core characteristic of Fully Refined Paraffin Wax is its "high purity and low oil content." Simply put, the higher the purity, the more stable the crystalline structure of Fully Refined Paraffin Wax, the more uniform the cooling process, and the less likely the candle will crack. Fully Refined Paraffin Wax with lower oil content has better hardness and is often used to make column candles or release candles. However, it is correspondingly more sensitive to cooling rate. If it cools too quickly, the surface hardens first, followed by internal shrinkage, leading to cracking.
The melting point of Fully Refined Paraffin Wax is also a key influencing factor. For example, if you use 60℃ Fully Refined Paraffin Wax to make a mold candle with an 8cm diameter, it will shrink significantly during cooling. If the pouring temperature is not well controlled, cracking is almost inevitable. When exporting, Junda Wax recommends the appropriate paraffin wax type based on the customer's candle type. For example, medium melting point wax is generally used for container wax, while high melting point wax is used for column wax. If the wrong raw material is selected, the resulting candle may also be unsatisfactory.
III. Why Do Candles Crack?
The fundamental reason candles crack is that wax contracts faster than its surface solidifies. When you pour hot wax into a mold, the outer layer first contacts air, cooling and solidifying first. Meanwhile, the interior remains hotter, continuing to cool and contract inward. By this point, the outer layer has already hardened. As the interior continues to shrink, it inevitably forces the outer layer to crack. This is especially common in large pillar candles or candles made in complex molds, where the significant volume and temperature differences increase the likelihood of cracking. The following factors further exacerbate cracking: - Pouring temperature too low, causing excessive cooling speed - Mold too cold, leading to instant solidification of the outer layer - Low ambient temperature, especially in winter with low humidity and dry air accelerating cooling - Improper selection of paraffin purity or melting point - Unreasonable pouring methods, such as overfilling in a single pour Many small factories rushing to meet deadlines like to use fans or air conditioning to speed up cooling.
IV. How to Prevent Candle Cracking?
In fact, carefully controlling temperature, cooling speed, and raw materials can significantly reduce cracking. The following techniques are used by nearly every Junda Wax export customer.
First, ensure the pouring temperature is sufficiently high. Generally, for Fully Refined Paraffin Wax molded candles, pouring within the 75°C to 85°C range yields the best results. If the temperature is too low, the surface cools rapidly, making cracking almost inevitable. At the right temperature, cooling is slower, allowing the interior and exterior to cool simultaneously, thus maintaining a flawless appearance.
Second, ensure slower cooling. It's best to let candles cool naturally in a cool, shaded area. Avoid placing them near fans, air conditioners, or windows in winter. Many factories have dedicated temperature-controlled workshops for this purpose, significantly improving daily production yields.
Mold preheating is also critical, especially for metal molds. If the mold is cold, the extreme temperature difference when hot wax is poured in can cause cracks. Therefore, molds are typically preheated to around 40°C.
For large candles, the two-pour method can be used: first pour 90% of the wax, wait until the interior cools and forms a slight depression, then pour the remaining wax to fill it completely.
Of course, many factories also incorporate microcrystalline wax, stearic acid, or vegetable waxes to enhance paraffin's toughness and cooling stability. We supply these materials as well, and many clients request us to blend the wax mixture directly according to their candle recipes, saving them trial costs.
V. To Reduce Cracking, Supply Chain Matters More Than Technology
Many assume candle-making is simply buying paraffin and adding fragrance, but those who produce candles at scale know the truth: 50% of candle quality comes from raw materials, 30% from equipment, and only 20% from craftsmanship. Some clients initially only purchased Fully Refined Paraffin Wax from us, but later entrusted us to ship their entire candle kit—including wick lines, dyes, glass cups, molds, and even candle machinery. This shift came after they experienced compatibility issues when sourcing from multiple suppliers, leading to color settling, fragrance separation, and worsened cooling problems.
Junda Wax offers a comprehensive product range including:
Fully refined paraffin wax, semi-refined paraffin wax, microcrystalline wax, vegetable wax
Wax wicks
Liquid/solid dyes
Fragrance oils
Molds, metal cups, glass cups
Automatic pouring machines, wick twisters, cutting machines, and other candle equipment
Junda Wax exports to countries including Vietnam, Malaysia, the Philippines, Saudi Arabia, Egypt, Poland, Romania, Turkey, South Africa, Kenya, and more. Some customers have evolved from initially purchasing only Fully Refined Paraffin Wax to now sourcing their entire production lines from Junda Wax—a testament to the recognition of our products and their reliability.
By selecting the right paraffin grade, mastering the optimal pouring temperature, controlling the cooling rate, and incorporating auxiliary techniques with compatible raw materials, you can produce exceptionally beautiful, structurally stable candles. In the long run, standardizing all raw materials, consumables, and equipment will stabilize the entire production process and ensure more consistent finished product quality.
We not only export Fully Refined Paraffin Wax products but also provide global candle brands and factories with wax lines, dyes, fragrances, molds, glass cups, and automated candle machinery. This helps clients transition from trial candle production to stable candle manufacturing. If you're interested in our products or production advice, feel free to contact us anytime. We also welcome visits to our factory, where we can tailor the most suitable candle raw materials and production line solutions for you.
