Jan 27th, 2019
Howdy Makers! I’m Rachel, the Idea Foundry Metal Shop Instructor and lover of metal melting! Through my years of teaching welding at Idea Foundry, I have learned a number of plasma cutting techniques to share with students. The first thing you need to know is how to get smooth, clean cuts with the Plasma torch.
First and foremost always check the electrode on the torch. The electrode on Idea Foundry’s Hobart AirForce 500i is silver in color and threads onto the torch. Checking the electrode is important because a consumed electrode will create poor cut quality- if it cuts at all. Over time if a consumed electrode is continually used, the arc will eventually damage the torch.
The electrode has a small amount of tungsten in its center, which is a terminal for the electric arc. This is transferred to the workpiece while the ground clamp is connected. If you want to learn more about exactly how a plasma cutter works and creates an arc, check out www.lincolnelectric.com.
While using the plasma cutter it is extremely important to wear a helmet on shade 5-9 and gloves. Idea Foundry has auto-darkening helmets that can be set to shades 5-13 and have front facing sensors that trip the auto-darkening feature when UV light is coming from the plasma cutter or MIG welder. Plasma cutting requires a shade darkness of at least 5 while MIG welding requires shade 9-13. Check out this shade chart from Lincoln Electric for all of your welding project. Gloves are also important because as you cut your workpiece heat is retained and radiants throughout, which can make your parts hot to handle after plasma cutting.
- Hold the torch tip perpendicular to the surface of your workpiece to ensure clean cuts with the ideal amount of kerf, which is the opening/cut created by the plasma cutter.
- Brace an elbow on a hip to help stabilize the plasma cutting torch. Use both hands on the torch, resting a non-dominant hand under the torch and against the surface of the material that is being cut.
- Do a test cut on a scrap piece of metal that is the same gauge (thickness) as the workpiece material to learn the proper setting for the gauge of material that is to be cut.
- While plasma cutting, hover 1mm above workpiece surface or less than a 1/16” of an inch, which helps the plasma cutter connection to the ground. The ground completes the connection to the arc and tells it where to go. Do not drag the tip of the torch on your workpiece. You will wear out the electrode faster than necessary and damage the torch.
- If you drag the torch tip across the surface of your piece it will create slag/high carbon steel which will prohibit you from making nice smooth cuts,. Slag is a mixture of metal oxides and silicon dioxide and it comes off easily while it’s still warm using a chip hammer.
Thanks for tuning in with us! Look out for our next video “Best Pace For Cutting with The Plasma Cutter”.