What Is Dross in Plasma Cutting and How to Reduce It

Jul 20, 2023 | Plasma Cutting Tips

If you want some exciting ideas about how to put the latest plasma cutters to work, call Cyrious Metal Works!

Anything worth crafting will have some useless leftovers to clean up, but what is dross in plasma cutting? If you have fabricated parts from metal, you may notice this pesky by-product called “slag” or “spatter.” These terms describe the re-solidified oxidized molten metal the cutting creates, which makes the final product look unpolished and can affect its integrity.

However, you don’t have to put up with the mess on your next plasma-cutting project! Keep reading as the specialists from Cyrious Metal Works share the many ways to minimize dross.

You Have Equipment Issues

Top spatter is one of the most common types of dross, where re-solidified metal sprays along the top of the cut piece. If it does, the problem doesn’t stem from your technique. Common culprits include the following:

  • Poor tool condition: Worn consumables or low-quality welding equipment can cause a significant increase in dross. Consider Hypertherm plasma cutters for cleaner, higher-quality output.
  • Incorrect settings: You might need to incrementally lower the voltage and torch height for improvements. Your tool’s user manual may provide more specific guidance.
  • High-frequency interference: Have your tools got the proper wiring and grounding before cutting? If not, you might see more dross.

Your Cutting Speed is Too Slow

What is dross in plasma cutting linked to? Often, our experts will point out that you don’t have enough speed for a clean finish. Cutting too slowly will force plasma systems to consume more metal to keep themselves alive. But as the arc widens, the cut becomes so large that the torch’s gas velocity can no longer clear away all the molten metal. 

What’s the result? A thick, globular layer at the bottom of the plate.

You can fix it by gradually raising your cut speed in five IPM increments. If you still see dross, check for excessive amperage and not enough standoff distance, which both boost energy from the jet to contact the material to make more spatter.

Your Cutting Speed is Too Fast

On the other end of the spectrum, fast cuts create even more slag. As the arc lags in the kerf, it leaves hard beads of uncut material along the plate, which are a pain to remove. You may also notice a rooster tail of sparks and molten metal as the arc destabilizes.

Decrease the cutting speed in five IPM increments, then try the following:

  • Replace the nozzle when you see gouging, elliptical shapes, or other signs of wear
  • Decrease the standoff
  • Raise the amperage (but don’t exceed 95% of the nozzle orifice rating)

If nothing works, consider switching to a CNC model.

You Need a Trusted Partner With Industry Experience

What is dross in plasma cutting? Now you know. And using quality equipment can prevent much of it.

Why not call Cyrious Metal Works at 903-345-1841 and invest in some premium-grade tools? You can also let our veteran crew do the heavy lifting for large and complex projects or explore our blog for plasma cutter safety tips!