How Does a Waterjet Cutter Work?

Marble inlay is an intricate process. It requires a skilled and watchful hand to design the art, craft it into marble and install it into your home. To create these marble designs flawlessly, a waterjet cutter is essential.

Some homeowners may concern themselves with the finished product — as long as it is installed correctly and the design meets their expectations, they are satisfied. Others want to know how the marble design is crafted. If you relate to the latter group, discover how waterjet cutters work and craft breathtaking marble designs.

What Is a Waterjet?

A waterjet is a manufacturing tool that can cut through thick metals and other substances with extreme precision, enabling technicians to cut intricate designs into tough materials. Some can even cut through diamonds.

Waterjet cutting machines allow technicians to do what was once considered impossible, or at least impossibly tedious, through the use of computer-controlled geometry and high-pressure jets of water. With that technology, a waterjet can cleanly cut through the following materials with precision:

  • Acrylic
  • Aluminum
  • Brass
  • Carbon steel
  • Ceramic
  • Copper
  • Fiberglass
  • Foam
  • Glass
  • Granite
  • Linoleum
  • Kevlar
  • Marble
  • Plexiglass
  • Stainless steel
  • Titanium

Waterjet machines are also quite large. A small waterjet machine is around 2 feet long and 2 feet wide, while a large waterjet machine can be as substantial as 46 feet long and 13 feet wide. Considering that bulk, the essential parts of a waterjet machine include:

  • A hydraulic intensifier water pump
  • A sapphire, diamond or stainless steel nozzle that directs the high-pressure water into a single beam
  • A hydraulic accumulator for water pressure regulation
  • A computer-based control system to ensure steady flow and accurate cutting
  • A valve to control the flow of water
  • An X-Y Traverse system to direct the cutting head along the desired path
  • A cutting table that supports the material with slats to prevent damage to the table

Depending on the machine’s size and technology, there may be additional parts on a waterjet cutter. Some waterjets mix an abrasive substance with the water, such as crushed garnet, which is added to the water flow through an abrasive inlet and mixed in a tube moments before the mixture exits the diamond or sapphire nozzle. An abrasive waterjet can cut through 12-inch thick materials at maximum, but most applications only require it to cut through materials that are three inches thick on average.

Other waterjets include a multi-axis cutting head for making angled cuts with computer-controlled precision. Newer models also substitute a hydraulic intensifier pump with a crankshaft-driven pump, which is more efficient and creates increased pressure.

How Does a Waterjet Work?

As a water-based cutting system, waterjet is a non-thermal, mechanical process that uses accelerated erosion to cut through materials. As such, it contrasts plasma and laser cutting methods. When abrasive grit is added to the water, it accelerates the erosion of the material, like a toothed blade, and it does so at rapid speeds and splitting pressures.

Inner Workings of a Waterjet

Not to be confused with a pressure washer to wash your car, waterjet machines pump out water through a nozzle at upward of 55,000 PSI and 700 mph. In comparison, a pressure washer pumps out water anywhere between 500 to 3,000 PSI. When cutting, waterjets use between a half to five gallons of water per minute (GPM).

This pressurized stream of fast-flowing water exits through a nozzle opening that ranges from 0.075 to 0.4 mm in diameter, creating a razor-sharp edge to cut through the material. Waterjet nozzles are typically made of sapphire or diamond because those materials are highly durable and protect against erosion. However, some nozzles may consist of hardened or stainless steel.

When this high-pressure and high-velocity beam of water contacts the targeted material, it cuts through it like a slice of cheese. However, since water is liquid, it tends to bend slightly when it cuts through material, causing rounded corners and curves. To correct this movement, the computer-driven cutting head predicts the motion of the water and adjusts accordingly to ensure the cut is straight and precise. The waterjet also cuts material at different speeds depending on how difficult it is to cut.

How Professionals Use a Waterjet

Before getting into the details of how to use a waterjet, it is important to note that only individuals with certified waterjet training should operate a waterjet cutter, due to the power and potential for damage the machine can cause through improper use. With that said, here are the ten 10  basic steps to using a waterjet:

  1. Set parameters in the computer and generate a cutting path
  2. Ensure the machine exterior is free from obstructions
  3. Open the water valve
  4. Remove pieces of previous projects from the machine
  5. Refill garnet hopper with abrasive additive
  6. Home the machine, i.e. command the machine to go to its default position
  7. Set material in proper position beneath cutting head
  8. Check the water line
  9. Test the garnet hose
  10. Make the cut using computer controls

Waterjet Designs for Marble

We have covered what a waterjet is and how it works, and those details come together to create endless marble design options. Here is why waterjet is the ideal stone-cutting tool and some of the design options waterjets can create.

Cut Tiles With Near-Zero Risk of Damage

When used properly, a waterjet will cut through marble cleanly without chipping or damaging the material. Because waterjets operate through a mechanical process of accelerated erosion, there is no risk of thermal damage to the material. While other mechanical cutting methods like lathes are slow and can easily cause minor chips here and there in the material, waterjets’ speed and pressure create smooth cuts quickly.

Design Identical Inner and Outer Inlay Pieces

Waterjets can easily create identical inner and outer pieces for marble inlay, ensuring the finished marble inlay design precisely matches your vision for the artwork, tile or medallion.

Create Intricate Designs

Unlike most other cutting machines and methods, the computer-driven mechanisms of waterjet machines allow them to create intricate curves and precise geometrical designs. There is no better tool for crafting marble medallions with lavish designs.

Layer Tiles

In addition to creating geometrically complex designs with interweaving lines and delicate curves, waterjet machines can also produce layered designs to provide a sculpted look to your walls or ceilings.

Engrave Marble

A waterjet machine can carve engravings in marble like a needle in clay. No matter how complex the design you wish to carve into your marble medallion is, a waterjet can deliver the finished product with astounding precision.

Contact Aalto Marble Inlay

At Aalto Marble Inlay, we custom-make all of our classically-inspired marble medallion designs using a state-of-the-art waterjet machine. Our artists create the designs according to your vision, and our skilled artisans craft the design in marble through waterjet cutting. If you would like to learn more about our process for creating marble medallions and designs, we welcome you to contact us today.