Cuts steel like a knife through butter

There are a few ways to cut metal, but one of the quickest and most fun is with a plasma cutter!

A plasma cutter uses a combination of electricity and air pressure to create an incredibly high temperature that melts metal. These cutters can cut anything that conducts electricity: steel, aluminium, copper, iron and stainless steel.
This model, the Disston CUT-40D air plasma cutter, consists of an inverter, a negative grounding cable and clamp, an air regulator and the cutting torch. In addition to mains power, you also need an external air compressor capable of a constant 4.8 – 5.5 bar of pressure.

It’s simple to assemble the plasma cutter: the earth or grounding cable, the torch connector and the torch on/off control all attach to the front. The master switch and the air regulator (where the air compressor is attached) are situated at the back.

The Disston CUT-40D can be adjusted from 5 amps up to 40 amps, depending on the material you need to cut. If you’re cutting thin steel, 5 amps will be enough, while thick steel (10 mm is the maximum thickness) will need 40 amps. Softer materials like aluminium also need lower amps.

Plasma cutters are ideal versatile cutting tools, allowing you to cut in straight lines (by using a guide) as well as tight angles, freehand designs and cut-outs in the middle of the materials. They cut with virtually no resistance, but it does take practice to cut neatly.

These cutters cannot operate non-stop due to thermal overload or overheating. In the case of the Disston, the duty cycle (the percentage of a 10-minute cycle) is 60%. This may seem confusing, but all it means is that you should limit your cutting to 6 minute periods followed by 4 minutes of rest. If you exceed this you could damage the cutter.

Using the cutter is easy, but personal protection equipment is vital: remember, we are generating temperatures hot enough to separate neutrons and electrons! You don’t want to get your bare skin anywhere near the cutting torch. Sparks or bits of molten metal could fly around, too, so make sure that you use safety glasses, leather gloves and a leather apron. Also, have appropriate footwear on hand and fire retardant clothing. Clear your work area of flammable material.

Using the cutter: clamp the metal you’re cutting to the workbench and attach the grounding clamp to the inverter and to bare metal. Touch the nozzle to the metal you’re cutting and it will spark and start cutting. Sparks will fly at first, but once the cutter has cut through the metal the sparks will be directed downwards – if sparks start flying on the cutting surface then you’re moving too fast.

A plasma cutter is a welcome addition to the tool cabinet of hobbyists or those in the metal work industry.

Buy the Disston CUT-40D air plasma cutter on Builders.co.za