WHEN IS A WATER TABLE BEST FOR YOUR PLASMA TABLE?
November 5th, 2025
Choosing between a water table and a downdraft system is one of the most critical decisions when configuring your CNC plasma machine. While both systems aim to manage the smoke and debris inherent in thermal cutting, they offer vastly different operational benefits.
The Science of the Water Table
A water table (or waterbed) captures the bypass gases and molten dross by keeping the water level directly in contact with the material.
1. Lower Cost of Purchase
The most immediate benefit of a water table is the lower initial investment. Unlike a downdraft system, which requires the purchase of a high-capacity industrial dust collector, heavy-duty blowers, and extensive ductwork, a water table is a self contained unit.
2. Fume and Dust Extraction
A water table acts as a massive, natural filter. As the plasma torch cuts through the metal, the high-pressure arc forces smoke, sparks, and molten particulates directly down into the water, resulting in 90-95% captation.
Material Specific Considerations
- Mild Steel: The most common application for water tables. It provides clean edges and easy dross removal.
- Stainless Steel: Water prevents the "sugaring" effect on the bottom of the cut by cooling the metal rapidly.
- Aluminum: Caution is required. Cutting aluminum in water can create hydrogen gas bubbles, which is why Machitech doesn't recommend using a water table for aluminum cutting. If you do decide to cut aluminum, ensure your system is equipped with a water aeration system or "bubbler" to safely disperse these gases and prevent ignition.
Is a Water Table Right for You?
When finalizing your decision, the choice hinges on your specific production priorities and budget constraints. A water table is the superior choice if you want to avoid the high upfront cost of an external dust collector and prefer a self contained system that keeps your conditioned air inside the shop. It is the ideal solution for fabricators who prioritize a quiet workspace and high efficiency fume extraction that traps particulates before they become airborne.
