Expert: Neecie - 1/21/2011

Question
I'm doing a science fair project on what brand of candle burns longest. I have a few questions.

1) Does the thickness of a wick make a difference in how long it burns?

2) If all candles used for testing my question are the same height/weight, but a few are scented and the others are unscented, does it make a difference in how long the candle burns?

3) Does the temperature of the room affect how long the candle burns?

4) Why do some candles look porous while others look more solid?

5) Do small candles burn faster than larger candles?

6) Does a candlestick burn faster or slower than a thick candle?

7) What is the main difference in soy candles and paraffin candles?

Thank you for your expertise. =)

Answer
Hi Phoebe,

I will try my best to answer all your questions to best of my ability.  

1.Q. Does the thickness of a wick make a difference in how long it burns?

A. Yes, it certainly does make a difference in how a candle burns.  There are many different types of wicks on the market today.  There are wicks made of cotton, paper, hemp, etc.  Within the different types of cotton, paper, etc.  There is High Temperature Paper wicks, commonly called HTP wicks, cotton core, etc.  The performance of the candle will be greatly influenced by your ability to select the proper wick for each type of candle that you make. The wick will influence the burn time of the candle, scent throw and "sooting" or smoking during the candle’s life.

2. Q. If all candles used for testing my question are the same height/weight, but a few are scented and the others are unscented, does it make a difference in how long the candle burns?

A. I believe that if each candle has the appropriate wicking, the difference in burn time would be minimal.

3.Q. Does the temperature of the room affect how long the candle burns?

A. There are many different theories on this.  Some say yes, others say no. But I believe that fire is fire and it will burn no matter what.  I think the only thing that would make things burn faster would be by putting a substance on it to make it burn faster, such as gas.  Same goes true if you don't give the candle enough oxygen, it would burn slower.

4. Q. Why do some candles look porous while others look more solid?

A. All waxes are not created equal.  There are so many different types of wax.  There is paraffin, soy, beeswax, gel, palm, vegetable, etc.  All have different qualities to them.  Some manufacturers may modify them as well.

5. Q. Do small candles burn faster than larger candles?

A. Ounce per ounce it's all the same.  It might appear that a smaller candle is burning faster because of the smaller volume of wax.  What affect the burn rate is the type of wax and wicking material.

6. Q. Does a candlestick burn faster or slower than a thick candle?

A. See answer above.

7. Q. What is the main difference in soy candles and paraffin candles?

A. Boy the list is long when it comes to differences between the two.  But here is the main difference.

Paraffin wax is a heavy hydrocarbon that comes from crude oil. Paraffin waxes are produced by refining or separating the waxes out of crude mineral oils. Obtained from the ground, crude oil is a compositionally varied product, consisting of a mixture of hydrocarbons. Another name for crude oil is fossil fuel. Crude oil is transported to refineries where it is refined into finished products by complex processes. One of the many products derived from refining is lubricating oil. It is from the lube oil refining process that petroleum waxes are derived. There are three general categories of petroleum wax that are obtained from lube oil refining. They include paraffin, microcrystalline and petrolatum. Paraffin waxes are derived from the light lubricating oil distillates. Paraffin waxes contain predominantly straight-chain hydrocarbons with an average chain length of 20 to 30 carbon atoms.  I like to think of it as, it almost the same thing we put in our cars gas tanks.  It comes from the same source.

Soy wax, on the other hand is made from vegetable matter. Soy wax is a vegetable wax made from the oil of soybeans. After harvesting, the beans are cleaned, cracked, de-hulled, and rolled into flakes. The oil is then extracted from the flakes and hydrogenated. The hydrogenation process converts some of the fatty acids in the oil from unsaturated to saturated. This process dramatically alters the melting point of the oil, making it a solid at room temperature. The leftover bean husks are commonly used as animal feed. The U.S. grows the vast majority of the world's soybeans, primarily in Illinois, Iowa, and Indiana. So obviously by using soy wax for candles, it helps our American farmers, plus you get a candle that burns about 30% longer.


Hope that helps in your project!