How to Make Large Blocks of Clear Ice for Sculpting and Drink Making

This project shows you how to make clear ice blocks of almost any size. The largest was 25cm X 35cm X 25cm, limited only really by the size of my freezer. I also will show the ice saw I used to shape pieces after they were made, and techniques for cutting.

This ice can be used as the starter for sculptures, as clear windows for an igloo, treasure hunt in an ice wall, and cut into pieces of any size for clear ice in drinks and cocktails.

The principle of this design is directional freezing and keeping the liquid water constantly in motion.

You will need the following(as a minimum):

A freezer large enough to take the complete setup.

Water pumps : These are ebay $7 240L/Hour pumps, but anything that circulates the water will work. (Ebay name is DC12V 3m 240L/H Ultra Quiet Brushless Motor Submersible)

A container to hold the water. The rectangular container I use is the best because the polystyrene insulation can slide to any position on the straight edges.

Polystyrene for insulation : I used some flat-ish discard from packaging and hot glued it together into a box shape.

Optional (but strongly recommended components):

LED lighting strip : Mount this to the top of the water container at the transition from water to air.

Variable power supply : Although some of the ebay pumps come with a USB cable to run them, I use 12V pumps and a DC/DC converter with variable voltage out to adjust the speed and LED brightness.

Nichrome wire : For making an ice cutting tool.

Brackets : provide a rigid barrier to the container expanding and provide a mount location if you are freezing objects into the ice.

Pictured is my smaller ice maker with a Mario toy suspended in the middle of it.

Pictured in supplies section is the two water pumps I used, glued to some plastic that fits over the edge of the container wall. You'll want to minimum amount of material inside the container as possible, as it gets frozen into the block and has to be melted out.

These pumps hang on opposite ends and have the intake/outlet aligned so it makes a whirlpool like effect. If you only have 1 pump, it still generally works, but the quiet corner always freezes over. With two, no part freezes on the top.

The LED lighting is simple (cheap) strips of LEDs. These strips use resistors to regulate the LED brightness from a 12V supply, so they get warm all over(which is what we want). Wrap it around the at the junction where the water level normally tops out. By keeping this transition warm, no ice will form on the surface. Without it, the pumps tend to swirl the water above the resting height of the water, and it starts to freeze on the wall. The more that splashes on, the more that freezes, and it ends up blocking water flow.

Also in supplies is the polystyrene box, and how it fits over the water container. For the rectangular container, the box can slide up and down to any level. Its a tight enough fit that it stays wherever it is put, so it can be moved all the way to the bottom, or just rest on the top few cm. This was assembled by cutting the box (the ice cutter(below) doubles as a great polystyrene cutter) and hot gluing it together(dont get it too hot - it melts easily).

For the power supply for the water pumps and the LED lights, I used an old AC/DC transformer(that put out around 16V or so) and an adjustable step down circuit(pictured). Although you can just run your pumps and lights at constant voltage, I found that full power was putting out too much heat and slowing down the freezing process too much. By adjusting it down to about 10.5 volts, it was still doing the required job, but not adding too much extra heat.

The brackets to hold the sides in were just some L-Brackets held together with glue and wood sticks. They were important to stop the sides bulging out and restricting the movement of the insulating box.

Pictured here is the larger ice container I made. I dont like it as much, for these reasons.

The shape is tapered(so it could stack into itself if there were multiple empty ones). This means that an insulating box cant easily be made to fit the outside. The best I could do was insulate the lid(which was 'just' enough)

Its very heavy to lift. The potential for massive spills of water is high.

Because there is no side insulation, it doesnt freeze flat. It still freezes clear, but in a giant U shape around the walls. While this was useful when I was making a table sculpture, its annoying for most other desired shapes.

I reused the same water pumps, and added some coat hanger wire as the support to hold it in place(as it wouldnt fit over the wall of the container).

Pictured in supplies was a variable power supply and a regular hacksaw converted to be an ice saw.

To make this saw, I used Nichrome wire tensed between the two regular blade mounting points.

The wire was 26 Gauge 25 Ft Resistance , which was just the cheapest and fastest delivery wire on Amazon. If I was to buy more I would buy thicker wire, as this wire breaks easier than i would like. With a variable bench power supply, I dont think it matters what resistance you get - you can adjust the power as required.

Keeping the wire tense is important to make it cut well. By using a saw, it already had some of the features to make this easier.

On one side, it was mounted with a spring, and a plastic zip tie to provide insulation. This is needed, or it will short with the other side.

On the hand end, it was wrapped around the blade mounting holes while the blade tightening nut was at it loosest. Once the wire is twisted into place, tighten up the blade mounting nut. Tighten only until the spring starts to expand - there is no point in making it too tight. As soon as the wire heats up, it will stretch, and will stretch more if tight.

The power comes in on alligator clip wires. Attach the clips on the wire(not the frame).

With this nichrome wire(and about 20cm of cutting length), the power supply was running at about 4 amps/8volts. If left out of the ice, it would glow red hot. In the ice in a cutting motion, it only ever sizzled.

To use it, cut like a normal saw. Its not 'that' good for cutting ice - the large block shown took about 10 minutes to cut through. And, you have to clear out the melted water or it will refreeze behind the wire. I used the original metal hacksaw blades to wipe/saw clean behind the cutting tool.

Depending on what you want to do with the ice, you can also just cut it with hot water from a tap. Pictured is what happened when i wanted to sheets to act as windows, and wanted them thinner that a full size block. You lose a lot cutting this way, but its much easier to do.

The smaller box (15cm x 25cm x 20cm) takes about 2 days to freeze at full speed, longer if you slow it down for some purer freezing. When i was placing objects in the ice(to make an ice treasure hunt display) I found bubbles formed on the objects if I froze too fast. I could slow it down by sliding the polystyrene box down to the current frozen level. If I left it there, the ice was barely advanced at all - the heat from the LED and motors, being kept in by the insulation, was enough to stop it freezing. I would normally start the freezing process with the box completely off, or only at the highest level, depending on the initial water temperature.

The larger box only took about 3 days to freeze to around 70%. The final freezing was difficult and the walls were frozen, and starting to block the pump water flow, but the middle was only about 50% of the available height.

Pictured here is one of the first objects I froze into the ice. (itsa him, Mario!) That first view of it in the container is at completion - that's all ice. You can see how it looks from different angles, and how clear that one really was. I think I was using the insulation to freeze it very slowly.

It really does freeze only the pure water - whats left can be kinda gross. I had filled it from my laundry sink, which doesnt get much use. The unfrozen water is shown in the glass photo - maybe hard to see but it looks yellow and cloudy. I fill from my kitchen sink after this first one, so the residual water wasnt as bad as this normally, but it shows you the potential of purification that it can do for making clear ice for drinks.

Speaking of drinks, I tried using some ice moulds to make specific clear ice shapes. It didnt really work. As shown, the shape restricted the freezing direction, and it still looked cloudy. I've had some better success after this freezing it slower, but overall, I find it better to freeze without any moulds and just cut it to the shape you want afterwards.

Also, trying the get the moulds out of the large block was almost impossible without breaking something or melting most of the ice.

One of the art displays I made was putting objects in clear ice, and freezing them into a plowed snowbank(at a school). I thought that carving out the snow and placing these in, then adding heaps of water, would freeze them in place for the rest of winter. I did not anticipate the fervour that children would apply to extracting McDonalds happy meal toys. They dug them out and smashed the block on the ground to get them. It was after this that i made the larger ice container, to make sure they were too heavy for them to lift from now on.

Its also didnt look that great to be honest. The fish display looked pretty good, but for the others, some overnight frosting on the ice made them less than perfectly clear, so the dazzling effect was minimised.

I'm not much of an actual artist, but for a gaming friend I made an 'Ice Dice Table'. Using the smaller mould, I cut it in half to make two cubes. I took out the number holes with an iron. Using the large mould, it worked out well to make a table, as the legs were already reasonably formed by the uneven freezing shape. I cut out the excess using the electric wire ice saw.

However, repeated sessions out of the freezer to carve it,and then returned to the freezer to stop it melting too much, resulted in a haze over the surface. This can be cleaned off(by basically melting it with water again), but if there is too much melting, it causes the whole thing to crack in random ways, with stress fractures going anywhere through the block.

It does take a lot of setup and construction, but if you're after large quantities of clear ice, this is the way to go.

Whisky drinkers appreciate the huge clear ice cubes you can make that will fill a glass with one chunk. Windows in igloos/quinzees/ice caves will finally be clear and see-through(a big thrill for kids). Budding artists can sculpt on the cheap.

I've made dozens of batches of ice in the 1 year I've had them.