Does Wax Melt In Hot Water?
Introducing Wax
Wax is a class of organic compounds that are solid at ambient temperature, malleable, and hydrophobic. According to Wikipedia, waxes are “a diverse class of organic compounds” that include alkanes, lipids, and esters with high melting points.
Some common types of wax include paraffin wax, beeswax, carnauba wax, and microcrystalline wax. Paraffin wax is derived from petroleum and is commonly used in candles, cosmetics, and wax coatings. Beeswax is produced by honey bees and has applications in lubrication, candle making, and cosmetics. Carnauba wax comes from the leaves of a palm tree and is very hard with a high melting point. It is used in automobile waxes, furniture polishes, and dental floss.
A defining property of waxes is their melting point, which is higher than room temperature. The melting point can vary widely depending on the type of wax. For example, beeswax melts around 62-65°C whereas paraffin wax melts around 47-65°C. The high melting point allows waxes to remain solid at normal ambient temperatures.
Does Wax Melt?
Wax is a solid at room temperature, but it melts when heated. The melting point of wax varies depending on the type of wax. Beeswax, for example, melts between 144-147°F (62-64°C), while paraffin wax melts around 115-250°F (46-121°C) 1. Soy wax melts between 115-185°F (46-85°C).
When wax is heated to its melting point, the solid crystals loosen and allow the molecules to slide past each other. This transition from solid to liquid state is known as melting. As more heat is applied, more of the solid wax melts into liquid. The wax becomes fully liquid when all the crystals have melted.
So in summary, yes wax does melt when heated. The temperature at which it melts depends on the type of wax. Heating wax to its melting point causes the solid crystals to loosen and allows the wax to transition from solid to liquid state.
Melting Point of Wax
The melting point of wax refers to the temperature range at which solid wax transitions to a liquid state. Different types of waxes have varying melting point ranges depending on their molecular structure and composition.
For example, paraffin wax, which is composed of straight chain hydrocarbons, has a melting point between 47–65°C (116-149°F) [1]. Soy wax, made from soybean oil, melts between 54-97°C (129-207°F) [2]. Beeswax has a melting range of 62–65°C (143-149°F). The differences in melting points depend on the length of the hydrocarbon chains and strength of intermolecular forces between molecules.
Waxes with longer hydrocarbon chains and stronger intermolecular forces, like microcrystalline wax, have higher melting points of 140-200°F. Shorter chains with weaker forces, like paraffin, melt at lower temperatures [2].
It’s important to note melting point differs from boiling point. The boiling point is when a liquid turns to a gas, which is much higher than the melting point for most waxes. The melting point is simply when a solid wax transitions to a liquid state.
Heating Wax in Water
One of the simplest ways to melt candle wax is to heat it in water on your stove. The wax should be placed in a metal or glass container and then that container can be set in a saucepan or pot of hot water. The water helps to gently heat and melt the wax.
For the wax to melt, the water will need to be heated to at least the melting point temperature of the wax you are using. Most candle waxes like paraffin, soy, and beeswax have melting points between 120-165°F. So the water temperature should be set to reach somewhere in this temperature range to effectively melt the wax.[1]
Using hot water to melt wax provides a very even heating method compared to direct stovetop heating or methods like a heat gun. The wax melts gradually as the hot water transfers heat to the wax container. This prevents burning or scorching the wax. However, melting wax in water does take more time compared to more direct high heat methods.[2] Proper stirring can help speed up the process of melting wax in hot water.
Wax Interactions with Water
Wax is hydrophobic, meaning it repels water. This is because wax molecules are nonpolar while water molecules are polar. The polar water molecules are attracted to each other via hydrogen bonds, while the nonpolar wax molecules have no charges and do not interact with water.
When melted wax comes into contact with water, the lower density wax will float on top of the denser water. The wax forms a layer on the water surface rather than mixing with the water below. This is because the intermolecular forces between wax molecules are stronger than the forces between the wax and water.
For melted wax to fully mix into water, the water needs to be heated above the melting point of the wax. This allows the wax to melt and disperse into the hot water, overcoming the wax’s poor miscibility. However, as the water cools back down, the wax will begin to solidify and separate out again. The wax must remain molten for it to remain emulsified in the water.
Factors Affecting Wax Melting
Several key factors determine how quickly and completely wax will melt when immersed in hot water:
Water Temperature – The temperature of the water plays a major role. As a general rule, the hotter the water, the faster the wax will melt. Most waxes begin to soften around 140-150°F and completely liquefy between 180-200°F. Exceeding the wax’s melting point by 20-30°F helps ensure thorough melting.
Wax Type – Different wax compositions have varying melting points. Beeswax melts at 144-147°F while paraffin wax melts at 117-160°F. Soy wax melts at 115-135°F. Harder waxes with higher melting points require hotter water for melting.1
Wax Shape/Size – Smaller pieces or thinner layers of wax melt faster because of increased surface area exposure to the hot water. Large blocks melt slower from the outside-in. Shredding or grating wax can accelerate melting.
Duration – More time immersed in hot water allows the heat to fully penetrate thicker pieces of wax. Several hours may be needed for complete melting.
Agitation – Stirring or agitating the wax helps distribute the heat, bringing unmelted portions into contact with the hot water. This speeds overall melting.
Applications of Melting Wax in Water
There are several practical applications for melting wax in water, especially for crafters, artists, and candle makers. Some of the main uses include:
Candle making – One of the most common reasons for melting wax in water is to melt old candle wax in order to reuse it for new candles. The water helps moderate the temperature so the wax melts evenly without overheating. This allows candle makers to salvage wax scraps and rejected candles. The water bath method also helps combine different types of waxes. [Source 1]
Wax modeling/sculpting – Artists learning to model with wax often use a heated water bath to melt wax for shaping sculptures, models, and more. The water bath allows the wax to be melted at a low temperature in a controlled way. Once melted, the wax can be combined and shaped as desired. [Source 2]
Remelting old candles – Old jar candles or votive candles that have lost their scent can be revived by melting the wax in a water bath, adding new fragrance oils, and repouring into a new container. The water prevents scorching the wax. [Source 1]
Wax-based waterproofing – Melting wax in hot water allows a thin wax coating to be applied to various surfaces like cloth, paper or wood to make them water resistant. The bath melts the wax fully so it can soak into materials. [Source 2]
Melting Wax Safely
When melting wax, it’s important to take proper safety precautions. Hot wax can cause severe burns if spilled or splashed. Ensure you are handling hot water and melted wax carefully. Use potholders or oven mitts when removing containers of melted wax from heat sources. Set wax melting containers on heat-resistant surfaces and avoid picking them up while the wax is still liquid.
Proper ventilation is also key when melting wax. Vapors released from melting wax can be irritating to eyes, nose and throat. Melt wax in a well-ventilated area, or use a wax warmer that is designed to direct fragrance upwards and away from your breathing space. Opening windows, turning on exhaust fans, or melting wax outdoors can also minimize irritation from fumes.
Use proper equipment designed for melting wax, like a double boiler, slow cooker, or electric wax warmer. Do not melt wax directly on stovetops or over open flames, as this poses a fire hazard. Carefully monitor wax while melting to prevent overheating and potential ignition. Follow all manufacturer instructions for safe operation of wax melting equipment.
Taking simple precautions allows you to melt wax safely and avoid burns or breathing irritation. Handle melted wax and associated equipment with care, set up proper ventilation, and use gear made specifically for wax melting. With some caution, you can enjoy the fragrance of melted wax without putting yourself or your home at risk.
Alternative Wax Melting Methods
While hot water is a common way to melt wax, there are some other effective methods to melt wax as well:
Using a double boiler is a gentle way to melt wax. To use this method, place water in the bottom pot and place a heat-safe bowl on top filled with wax chunks. Heat the water to a simmer, melting the wax indirectly without scorching it. The water acts as a buffer regulating the temperature [1].
Wax melters or candle warmers provide another alternative for melting wax. These devices have a heated plate that warms up just enough to melt wax in a container placed on top. Melters allow melting wax safely at a very low temperature [2].
Low heat from a candle warmer or very low setting on a stove can also melt wax gradually over time without overheating it. This very gentle warming method takes longer but protects the integrity of the wax.
Summary
In summary, wax does melt when heated in hot water. The melting point of wax ranges depending on the type, but generally falls between 120-200°F. When wax is immersed in hot water above its melting point, the heat from the water will cause the wax molecules to start breaking apart and transition from a solid to a liquid state. Key factors that determine if and how quickly wax will melt in hot water include the type of wax, the temperature of the water, and the duration of heating.
Melting wax in hot water has many uses and applications. In candle making, hot water can be used to melt wax to specific pouring temperatures. Hot water baths are used to melt wax for waxing hair removal. Melted wax is also used in art, to make wax seals, or for wax-resist art techniques like batik. Overall, the ability of wax to melt in hot water makes it a versatile material across many contexts.
When melting wax in hot water, proper precautions should be taken such as wearing gloves, eye protection and avoiding steam burns. Alternatives to hot water for melting wax include using a wax warmer, microwave, or double boiler technique.
