Plasma isn't just for donating anymore! While most of you have heard of or seen plasma cutters (plasma arc cutting machines) by now, how many have used one? Lots of you may have an oxyacetylene torch out in the garage or shop as an old standby for stubborn parts or bolts, but what if you could transform that piece of ancient blacksmithing equipment into a finely tuned high-performance tool? That's essentially what a plasma cutter is-a torch for the 21st century.
But what is plasma and how does it cut? Plasma makes up the stars in the sky, is found in TVs, fluorescent lights, neon signs, and mighty lightning bolts, to name a few. It is an ionized gas that conducts electricity created by adding energy to an electrically neutral gas-most often oxygen. For plasma cutting, we combine compressed air (oxygen) and get energy from electricity. By adding electricity through an electrode, the gas becomes unbalanced and conducts electricity. The more electrical energy added, the hotter the plasma arc becomes. Plasma cutters control this powerful energy by constricting the arc and forcing it through the nozzle in the cutting torch. By increasing air pressure and intensifying the arc with higher voltages, the arc becomes hotter and more capable of blasting through thicker metals and blowing away the cuttings, leaving minimal cleanup and slag.
This fine-tuned plasma cutting arc makes much more precise cuts than an oxyacetylene torch, requires no preheating, cuts through multiple layers, leaves a minimal heat-affected zone, and can cut through any electrically conductive metal like stainless steel and aluminum-two metals that oxyacetylene can't cut. Of course, there are limitations to plasma cutters, mainly the portability issue. This isn't that big of a deal for those who use it at home or in the shop, but you are bound by the length of the power cord and air-supply line, whereas a torch can be rolled around outdoors easily. Like everything, there are pros and cons, but it all comes down to your needs and what you may want to do in the future. I've personally used a plasma cutter for framework, sheetmetal work, cutting stuff up for scrap, and making yard art, and haven't fired up a set of torches in several years now.
Of course, there are plasma cutters that range from mild to wild, and you should do your homework before buying any one of them. There are some good online resources from Miller and HTP to aid in your decision should you choose to buy. Also, don't be afraid to go to your local welding supply and ask to demo one so you can see it in action right before your (protected) eyes. Don't forget to follow all the safety guidelines since we are "playing" with a good deal of electricity and heat here. Be safe, smart, and have fun!
There are many plasma cutters out there, but the best keep getting better, like these unit
...and HTP (MicroCut 301). You still get what you pay for when it comes to specialized too
Depending on the brand you buy and the electrical outlets you have in your garage, you may