Start out by taking your smaller, narrower container and filling it with rocks.
Then put the smaller container in the larger container and start adding water.
The rocks you had added to the smaller container are used as weights to keep it from floating up from the bottom of the larger container.
If the smaller container starts to float, add more rocks or dump out some of the water from the larger container.
Put the container outside, or in the freezer, carefully positioning the smaller container so it sits directly in the middle of the larger container.
A flat surface is very important or you'll create a luminary that's uneven and one you won't be able to place a candle in.
I put my luminaries right on my deck outside of my patio doors so I can keep checking on the progress.
When the ice is frozen solid, take the containers back inside and remove the rocks from the smaller container.
Fill the smaller container with hot water and let it sit for a couple minutes until the container releases easily from the ice. Set the smaller container aside and look into the middle of your luminary.
At this point I take a look and decide how deep I want my candle to sit inside of the luminary. Most of the time I fill the hole with a bit more water so my candle will have a base that sits up a bit higher.time,
Once the water has frozen solid again, start running warm water around the sides of the large container until the ice easily releases from the container.
Notes
Ensure Stability with Proper Weight Distribution: When assembling your ice luminary, use rocks in the smaller container to prevent it from floating up when filled with water. Adjust the amount of rocks as needed to achieve the desired weight and stability, ensuring that the smaller container remains submerged in the larger one throughout the freezing process.
Optimal Positioning for Even Freezing: Position the smaller container carefully in the center of the larger container to create an evenly shaped ice luminary. Choose a flat surface to place the containers, as an uneven surface can result in an irregularly shaped luminary that may not accommodate the candle properly. This step is crucial for ensuring a visually appealing and functional final product.
Facilitate Easy Removal and Candle Placement: After the ice has frozen solid, remove the rocks from the smaller container and release them from the ice by filling it with hot water. Take the time to decide the depth at which you want the candle to sit inside the luminary, adjusting the water level accordingly. Once the desired depth is achieved, freeze the water again to create a stable base for the candle. When ready to remove the ice luminary from the larger container, gently run warm water around the sides to facilitate easy release without damaging the structure.