Does wax turn into liquid?
The melted wax acts as a fuel to keep the candle burning. Specifically, the heat of the flame turns the wax from a solid to a liquid, and then a liquid to a gas by breaking down the hydrocarbons into separate molecules of hydrogen and oxygen.
Heat Melts the Wax
In chemistry terms, the melting of the wax is a physical change that turns a solid to a liquid. As the heat continues and more wax melts, the liquid wax pooled around the wick slowly increases in volume and generates more thermal mass (heat capacity).
Candle Wax Combustion
Candle wax, or paraffin, is made up of a chain of carbon atoms surrounded by hydrogen atoms. Combined, it creates hydrocarbon molecules which can burn completely. This is why the wax close to the flame ultimately melts into liquid.
When you light a candle, the heat of the flame melts the wax near the wick. This liquid wax is then drawn up the wick by capillary action. The heat of the flame vaporizes the liquid wax (turns it into a hot gas), and starts to break down the hydrocarbons into molecules of hydrogen and carbon.
Wax is made of hydrogen and carbon. When a candle burns, the hydrogen and carbon from the wax combine with the oxygen in the air to become carbon dioxide and water vapor. Most of the matter in the candle ends up as these two gases.
A wax fire is created when melted or boiling wax is doused with water. The ensuing reaction creates a large fireball or dramatically enlarges the flame of the already existing fire.
Wax is a buoyant material, which means that it normally floats, rather than sinks, in water. Wax floats because it is less dense than the water.
Paraffin candles are made from petroleum-based wax that has a melting temperature of 99°F (37°C). Beeswax is a cleaner burning wax that has a higher melting temperature than paraffin, ranging from 144°F — 147°F (62°C — 64°C).
How does wax become liquid? The answer is heat transfer and change of state of matter when the heat is transferred to the solid wax but this change is just a physical change i.e the chemical constituents of the wax do not change it is just transformed from solid wax to liquid wax.
When we heat wax, it melts. The state of wax is solid before melting, which on heating converts to liquid wax.
Does wax harden after melting?
Wax isn't always as “hard” as it seems. Even in its solid, unmelted state, wax will continue to harden over time. Candle wax that was melted and cooled again yesterday will always be softer than candle wax that has been sitting around for a week.
All waxes are primarily hydrocarbons, whether the wax is of animal, vegetable, or petroleum origin. The chemical composition of all waxes used for candle-making is similar, and all candle waxes burn in the same manner. An estimated 1 billion pounds of wax are used in the candles sold each year in the United States.
During melting, wax typically expands in volume by 5–20% (Freund et al. 1982). A wide range of waxes can be used in wax motors, ranging from highly refined hydrocarbons to waxes extracted from vegetable matter.
According to The New York Times, most of a candle's matter actually ends up evaporating into the air. As the wax starts to melt and puddle around the candle's cotton wick, it actually travels upward. The wick soaks it up, and it eventually evaporates into the air as either carbon dioxide or water vapor after it burns.
Yet the physical properties of wax are consistent: wax is a pliable solid at room temperature that melts when heated. In its melted form, wax is low viscosity, meaning that liquid wax is runny and flows easily.
Use Boiling Water
Use a butter knife or spoon to remove as much wax as you can. Pour boiling water into the container, leaving room at the top. (If your candle is made of a soft wax, such as soy wax, you can use hot water that's not boiling.) The boiling water will melt the wax and it will float to the top.
All you need to do is put hot water on top of the wax. The heat will make all of the wax bubble up to the top of the water, where it will then harden.
DON'T POUR HOT WAX DOWN YOUR DRAIN!
The volume of the wax helps keep it in a liquid state by holding heat. However, when you pour it down the drain, that will dissipate the heat quickly and form into a solid. Once that happens, you have a problem. Even a small amount of wax can cause a sink to clog or drain slowly.
Because wax tends to be insoluble in water, you need to use a deep cleaning shampoo to get rid of it. If it's not removed thoroughly, a mixture of wax and scalp oil can build up on your scalp. Between washes, this mixture begins to oxidize and break down into potentially irritating substances.
Wax expands when it heats up and contracts when it cools. If you add fragrance oil (or essential oil) to wax while it's a hot liquid it will cool down and contract, trapping fragrance molecules inside it.
How much water is in wax?
As a general rule of thumb, you can convert water weight into wax weight by multiplying by 0.86 because the wax is approximately 86% as dense as water. Applying this idea to candle making, we can figure out how much total weight our candle is to find out how much wax and fragrance oil we need.
The most typical are acetone (found in nail polish remover) and isopropyl alcohol (used in rubbing alcohol).” Before proceeding, check the care label on the item for cleaning instructions. (Don't ever use acetone on modacrylic, acetate or triacetate because it will dissolve the fabric.)
For glass surfaces - Use a solvent-like window cleaner, rubbing alcohol, drain cleaner, bleach, or vinegar to dissolve the wax and separate it from the surface, making it easy to remove. Use a plastic putty knife to scrape up any excess wax.
