There are a lot of ways to make ice sculptures. One of the easiest is to pour water into a mold, freeze it, and then peel the mold away. These pieces generally aren't as clear and don't feature the kind of sharp edges of a true carving. And it's kind of cheating.
True works of art are hand-carved. Artists employ a range of hand and power tools to carve the block into a work of art. Chisels, hand saws, heat guns, nail boards, sanders, chainsaws, and die and angle grinders fitted with special bits are all parts of a sculptor's toolbox. Sculptors often learn their techniques in culinary school or at specialty classes dedicated to ice carving.
In the 1980s and 1990s, a sculptor named Mark Daukas propelled ice carving into new artistic territory. The Californian is a six-time national champion and won dozens of competitions around the world. His secret is no secret – he simply decided to start using power tools instead of traditional chisels.
Sculptors learn to work fast. Most typically wedding pieces are completed in just a couple of hours, and they work in large freezers chilled to temperatures much colder than your home fridge, at around 20 degrees Fahrenheit or even less.
Because they work with a medium that is delicate and brittle, it's not uncommon for artists to accidentally break parts of their designs. They can't just scrap the piece and start over again. So instead, they'll try to retrieve the broken piece (or fabricate a replacement piece), wet the end of it and press it to the main body and let the parts freeze together, a technique that's called welding. To accelerate this process, the sculptor may use butane to cool the ice and make it bind.
Horizontal breaks are easier to fix because gravity binds them. Vertical breaks may be impossible to repair, particularly if it's a heavy or extravagant shard.
Breaks aside, you can skip much of carving's manual labor and buy a CNC (computer numerical control) machine tweaked to carve ice – in essence, a robot ice cutter. To create a sculpture, you design it on your computer using any program that can create vector files (such as Corel Draw or Adobe Illustrator) and then connect to the CNC table. The machine is equipped with various bit sizes that you can swap out depending on the project.
Zip your design to the machine and it will automatically carve the ice for you in minutes. If it's a 3-D piece, once the carving is done on one side, you flip the ice over and the bit goes to work on the other side. Novices can operate the machine after only a couple of days of training, but the convenience doesn't come cheap. The Ice Carve Pro, for example, retails for more than $20,000. Some machines sell for as much as $50,000.