Sinkholes and How to Deal with Them

Even on a perfect day, the most carefully crafted soy wax candles can sometimes develop sink holes, leaving unsightly craters in the once-smooth surface.

But what exactly causes these sink holes to form? Let’s delve into the science behind this perplexing and annoying phenomenon.

Understanding Soy Wax Composition:

Soy wax is derived from soybean oil, making it a natural and renewable resource. It’s renowned for its clean-burning properties and ability to hold fragrance well. However, soy wax has unique characteristics that can contribute to the formation of sink holes.

Factors Contributing to Sink Holes:

1. Temperature Fluctuations:

• Soy wax has a lower melting point compared to other waxes, such as paraffin. Temperature fluctuations during shipping or storage can cause the wax to expand and contract, leading to the formation of sink holes.

2. Pouring Temperature:

• The temperature at which the soy wax is poured into the container can also impact the likelihood of sink holes. Pouring at too high or too low of a temperature can result in uneven cooling and the formation of sink holes as the wax solidifies.

3. Fragrance Oils and Additives:

• The addition of fragrance oils or other additives can affect the viscosity and density of the soy wax. Improperly formulated fragrances or excessive additives can interfere with the wax’s ability to bind together evenly, resulting in sink holes.

4. Cooling Rate:

• The rate at which the candle cools can influence the formation of sink holes. Rapid cooling or uneven cooling due to drafts or other environmental factors can cause the wax to shrink unevenly, leading to sink holes.

Prevention and Remedies:

1. Proper Pouring Technique:

• Ensuring that the soy wax is poured at the appropriate temperature and with proper technique can help minimize the risk of sink holes. Pouring slowly and evenly can promote even cooling and reduce the likelihood of imperfections.

2. Avoiding Overheating:

• Overheating the soy wax can lead to excessive shrinkage and the formation of sink holes. It’s essential to melt the wax gently and avoid prolonged exposure to high temperatures.

3. Temperature of the Vessel:

• It is essential to consider the temperature of the glass to ensure optimal adhesion and minimize the risk of issues like thermal shock, sinkholes or cracking. The ideal temperature for glassware when pouring candles is between 37°C to 65°C.

• Too Hot: If the glassware is too hot, it can cause the wax to cool too quickly upon contact, resulting in uneven adhesion to the glass walls and potentially trapping air pockets or causing sink holes. Additionally, extreme temperature differentials between the hot wax and the glass can lead to thermal shock, which may crack or damage the glass.
• Too Cold: On the other hand, if the glassware is too cold, it can cause the wax to solidify too slowly, leading to a longer curing time and potential surface imperfections. Moreover, pouring hot wax into very cold glass can also increase the risk of thermal shock.

4. Using Quality Ingredients:

• Using high-quality soy wax and fragrance oils formulated specifically for candle-making can help prevent sink holes. Avoiding excessive additives or poorly formulated fragrances can contribute to a smoother burn. We recommend Illumina Candle Supplies> Of course we do!

5. Post-Pouring Care:

• After pouring the candle, it’s crucial to monitor the cooling process and minimize temperature fluctuations. Keeping the candles in a controlled environment with stable temperatures can help prevent sink holes from forming.

Still have a sinkhole and need to fix it?

Fix it Tip #1: Heat Gun

• With heat gun on low heat, gently heat the top layer of wax, and lightly tap the side of the container to encourage any hidden bubbles to travel up to the surface and pop. You may have to do this more than once.
  
  

Fix it Tip #2: Top Layer

• If you have a bit of room to add some more fragranced wax, you could melt a bit of wax and pour a thin layer over top. We also recommend lightly heating the top layer just prior to adding the new layer for a perfect result.
  
  

Whichever method you use, keep an eye on your repair job as you may need to gently tap the side of the container again.

Feel free to reach out to the Illumina Team at any time for any questions you may have and remember to check out our handy tips!

By preheating the glassware to a moderate temperature, you can create an environment that promotes even cooling and adhesion of the wax to the glass surface. A good practice is to warm the glassware gently in an oven or with a heat gun, ensuring it reaches the desired temperature range before pouring the melted wax.

3. Fragrance Oils and Additives:

• The addition of fragrance oils or other additives can affect the viscosity and density of the soy wax. Improperly formulated fragrances or excessive additives can interfere with the wax’s ability to bind together evenly, resulting in sink holes.

4. Cooling Rate:

• The rate at which the candle cools can influence the formation of sink holes. Rapid cooling or uneven cooling due to drafts or other environmental factors can cause the wax to shrink unevenly, leading to sink holes.
  
  

Prevention and Remedies:

1. Proper Pouring Technique:

• Ensuring that the soy wax is poured at the appropriate temperature and with proper technique can help minimize the risk of sink holes. Pouring slowly and evenly can promote even cooling and reduce the likelihood of imperfections.

2. Avoiding Overheating:

• Overheating the soy wax can lead to excessive shrinkage and the formation of sink holes. It’s essential to melt the wax gently and avoid prolonged exposure to high temperatures.

3. Using Quality Ingredients:

• Using high-quality soy wax and fragrance oils formulated specifically for candle-making can help prevent sink holes. Avoiding excessive additives or poorly formulated fragrances can contribute to a smoother burn.

4. Post-Pouring Care:

• After pouring the candle, it’s crucial to monitor the cooling process and minimize temperature fluctuations. Keeping the candles in a controlled environment with stable temperatures can help prevent sink holes from forming.
  
  

In Conclusion:

While sink holes in soy wax container candles may seem like a frustrating occurrence, they are often a result of various factors that can be managed with proper technique and attention to detail. By understanding the underlying causes and implementing preventive measures, candle makers can create beautiful soy wax candles that burn evenly and flawlessly, enhancing the ambiance of any space.

Feel free to reach out to the Illumina Team at any time for any questions you may have and remember to check out our handy tips!