Problem
Why does a candle sink?
A dip in the middle with a high edge: air remains as the wax shrinks. Cool slowly without drafts; a second pour with the same recipe fills it. A fridge causes cracks.
Why it happens
Liquid wax loses volume as it cools. The edge by the glass sets first, the center sets late, and air is drawn in. Soya Wax 50 is a soft container base; with sudden cooling the dip becomes pronounced. Excess fragrance (above the 8% oil saturation) and a thick pour also enlarge the void.
What to do
Keep the room draft-free. After the first set, melt the same wax again in the 51–55°C band (Soya Wax 50) and fill the dip: the second pour. Poking a hole to let air escape works in thick containers; do not force it in thin glass.
What not to do
A fridge, under an air conditioner and a damp worktop produce dips plus cracks. Do not fill the dip with random fragrance. In a molded candle, a sinkhole can also be air escaping from inside the mold; see the silicone guide.
Sinkhole: decision
| Observation | First move |
|---|---|
| Dip in the middle, firm edge | Second pour |
| Air line at the glass | Pour slowly, tap lightly |
| Dip + cracks | Slow down the cooling |
| Dip on the surface + soot | Wick and load are separate problems |
FAQs
Is a candle with a dip defective?
It does not spoil burning. Fill it for looks and for wick height. The wick must not be buried.
Does soy or paraffin sink more?
Both shrink. Soya Wax 50 in a container can show a dip with soft cooling; paraffin in a mold gives a surface dip. Do not cool quickly.
Choose Materials From Stock
You can order the product groups in this guide by quantity from the Rufus Concept catalog.