Understanding the Basics of Exothermic Cutting

Exothermic Cutting Basics That You Need To Know

The exothermic reaction is a process that releases energy in the form of heat and light. When used in cutting, the exothermic process uses oxygen as an exciter and steel rod as a fuel. In this article, we will walk through exothermic cutting basics.

What Is Exothermic Cutting?

The exothermic cutting process uses a technology that allows cutting, piercing, or gouging of almost any ferrous or non-ferrous material including iron, steel, magnesium, and aluminum. Exothermic cutting is widely used in building renovation or demolition, plant maintenance, salvage work, scrap clean-up, metal fabrication, and mining. The cutting technique is capable of burning through rust or mud-covered machinery frames. It also helps remove edges on loaders for replacement and repairs.

Exothermic cutting is extensively used for pin removal in heavy equipment. The cutting process is also used in Fire and Rescue. Many manufacturers sell packs that include a complete setup – a torch, oxygen cylinder case, and power supply. These can be carried by handles or as a backpack for ease of carrying and use.

Tips for Exothermic Cutting

Exothermic cutting procedure varies based on the job. The standard process for exothermic cutting is done by a drag technique. When the rod is in contact with the piece to be cut, the rod is dragged in the direction of the cut.

Here are some useful tips to achieve a perfect cut:

• Always maintain a proper travel speed. The speed of the cut tends to get too fast when the kerf is not visible to the operator and metal blows back at the operator.
• Always keep the rod in contact with the workpiece for cutting. If the rod is not in contact with the workpiece, the rod is being used without cutting.
• For cutting materials thicker than 1-1/2" to 2", use a sawing motion to completely melt through the metal.
• Use a smooth motion to complete the cut.
• On completion of the cut, you need to release the oxygen control lever in the handle.
• Hold the torch away from your body until the rod cools.

Tips for Piercing

When piercing surfaces, you need to follow certain procedures to ensure safety and a high-quality finish. The use of a collet extension helps add life to the torch. Using a hand shield improves operator safety and comfort. Make sure to wear PPE to protect yourself from the heat, fumes, and sparks generated from cutting. Always hold the torch at an arm’s length. To prevent the cutting rod from getting trapped inside the pierced hole, remove the cutting rod from the hole before you release the oxygen lever.

To Pierce Solids:

• Hold the torch at an arm’s length
• Strike the cutting rod on the striker
• Place the cutting rod at a 90° angle to the pierce point
• For better results, gradually push the cutting rod in at the pierce point until you achieve the burn through

Oxygen Usage

Oxygen usage is a crucial aspect of exothermic cutting. Standard industrial grade oxygen is used for exothermic reactions to remove the molten metal during cutting. Arcair Slice equipment uses standard oxygen fittings.

The recommended operating pressure is 80 pounds per square inch (psi). Cutting material sections of 3" and thicker requires higher operating pressures. Low operating pressure of 40 psi is suitable for some applications, including scarfing out minor cracks for repair and washing off rivet heads.

For cutting rods at 80 psi, the oxygen consumption rate is 7 to 7.5 cubic feet per minute (cfm) for 1/4" diameter cutting rods and 11 to 12 cfm for the 3/8" diameter cutting rods. The rates vary in case different operating pressures are used.

The exothermic cutting process varies from job to job. Based on the type of project, making some adjustments in operating conditions can help ensure you get the best of your cutting equipment and achieve the required safety requirements.

ESAB is a world leader in the production of welding and cutting equipment, consumables, and automation equipment. We can answer questions you have about welding and cutting. Our intelligently designed welding and cutting equipment with advanced technology can help you accomplish your welding and cutting projects.