Bubbles in gel candles seem to cause a lot of distress among candle makers, yet many don’t understand what is causing them. There are several causes:

• Stirring the gel wax too vigorously - this introduces air.
• Embeds that contain air - porous items such as sea shells
• Embeds that can trap air - such as sand

Some may be saying “I use those in paraffin wax with no problem - why should they be a problem in gel wax?” Simply because the 2 types of wax have very different properties - the shells and sand still release and trap the same amount of air in paraffin wax, but it doesn’t stay in (usually) or is hidden by the opacity of the paraffin (less commonly).

Paraffin wax is very thin when melted or in technical terms has a low viscosity. Gel wax on the other hand has a high viscosity when melted. Because of this any bubbles released in a gel candle will travel to the surface very slowly.

Gel wax also solidifies much faster than paraffin wax, thus trapping many air bubbles that were slowly working their way to the top and out of the candle. Paraffin wax on the other hand takes substantially longer to set and by then any trapped air is long gone.

Funny Fact - Air bubbles never stop moving upward in gel wax even after it has solidified, although very slowly. If you let a gel candle sit long enough eventually there will be no air bubbles. Unfortunately the time this takes is measured in months, so don’t plan on using it as a way to get rid of bubbles on a regular basis.