The reason why the concave shape occurs is because wax shrinks when it cools and expands when heated. The outside/top of the wax will begin to cool first, leaving the middle relatively warm (and sometimes liquid for a while). When the inside begins to cool, it has to shrink down as well, and since the wax is not completely hardened yet, it is essentially sucked into the middle as it cools. It's quite an interesting sight. I've experienced it a lot with my candle-warmer. Cool vid!
The reason why the concave shape occurs is because wax shrinks when it cools and expands when heated. The outside/top of the wax will begin to cool first, leaving the middle relatively warm (and sometimes liquid for a while). When the inside begins to cool, it has to shrink down as well, and since the wax is not completely hardened yet, it is essentially sucked into the middle as it cools. It's quite an interesting sight. I've experienced it a lot with my candle-warmer. Cool vid!
ct6mblack 2 years ago