Dumb plasma torch question

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I dont have a plasma torch so I cant try this at home but, Nitrogen is supposed to work best for a plasma torch but has anyone ever tried a different inert gas? Wouldnt Argon or Co2 work better for certain metals/cuts compared to plain old air? I know its not cost effective to waste your gasses when air works but has someone  tried it somewhere?
Reply:I'm not sure where you got the notion that "Nitrogen is supposed to work best for a plasma torch".Air plasma torches (most manufacturers and models) can use either nitrogen or air as the plasma gas. The torches and gas delivery systems are not designed to use any other gases.....and it can be unsafe to do so.Air, which is roughly 80" nitrogen and 20% oxygen doe s a great cutting job on steel....due to the exothermic boost (same way an oxy-fuel torch operates) from the oxygen content. The oxygen increases cut speed at a given amperage, reduces dross, and improves cut edge angularity. Air also works very well on aluminum and stainless from a dross and speed point of view (the oxygen content affects the molten metal flow....which helps to eliminate dross).....but expect porosity and roughness on aluminum edges and an oxidation on the edge of stainless.Nitrogen does not cut steel as well as air. It is slower, it will produce a more tapered edge, and expect dross formation. On aluminum and stainless there may be some edge quality improvement in terms of smoothness and taper, but generally more dross. If you can submerge the torch under about 1" of water while cutting stainless with nitrogen....the water keeps ambient air away from the cut edge and will eliminate the edge oxide (brownish appearance) that is normal on stainless.Industrial plasma systems that are designed for use with other gases use a few different gas combinations to achieve best cut quality. Here are a few examples: (note: the first gas listed is the plasma gas, the second is the shield.)Oxygen/Air.   The best process for cutting carbon steel from 30 amps through 400 amps in thicknesses of gauge to 3". Produces a relatively soft, weldable edge with minimal dross and excellent edge squareness at extremely high speeds.Oxygen/Oxygen. This is used on Hypertherm systems only that are equipped with TrueHole technology, a way to cut holes in steel plate with no taper. Only used for holes, not for contour cutting.Air/Air. Cuts similar to conventional air plasma systems....typically used where bottled gases are not available.Nitrogen/Carbon Dioxide. An older process that is used primarily on stainless and aluminum for better edge quality and minimal oxidation.Argon-Hyprogen/Nitrogen. A premix of argon (65%) and hydrogen (35%) is used on stainless steel thicker than 1/4" for clean, weldable edges with no oxidation. This gas mix is used between 130 and 800 amps for cutting from 1/4" to 6-1/4".Argon/Nitrogen. Aegon does not cut aggressively....but works very well in plasma arc marking. On systems that are equipped with the ability to use this gas mix and can produce output power below 15 amps....plate layout and market is acccomplished.Argon-Nitrogen/Nitrogen. Also known as F5, a premix of argon (5%) and nitrogen (95%) is used to cut thin stainless (from gauge to 1/4") with a clean, weldable edge. Amperage ranges from 30 to 80 amps typically.Nitrogen/Nitrogen. Typically used for stainless steel cutting from gauge to 2" at amperage ranges from 30 to 400 amps. An improvement over air/air cutting on stainless and aluminum. Best cuts are submerged under water on stainless to keep ambient air away from cut edge.Once again....it can be dangerous to use gases that your plasma systen is not designed to use!Jim Colt   Hypertherm   Originally Posted by InsanerideI dont have a plasma torch so I cant try this at home but, Nitrogen is supposed to work best for a plasma torch but has anyone ever tried a different inert gas? Wouldnt Argon or Co2 work better for certain metals/cuts compared to plain old air? I know its not cost effective to waste your gasses when air works but has someone  tried it somewhere?
Reply:I got the "notion that Nitrogen was better" because its dry and air is mostly Nitrogen. I still dont understand why Argon wouldnt work in a regular plasma torch but I recognize your name and you are obviously the xpert. Thanks for the thorough xplanation. Interesting , useful and informative.
Reply:Argon will produce a plasma in some torches....and will not in others. It takes more energy to ionize. It also is much less aggressive and produces a lower temperature arc than many other gases.....this is the reason why it it used for arc marking. With the marking process you do not want to cut through....just etch the surface.Argon makes a great shield gas....but is too expensive to be used for this purpose.Jim Colt Originally Posted by InsanerideI got the "notion that Nitrogen was better" because its dry and air is mostly Nitrogen. I still dont understand why Argon wouldnt work in a regular plasma torch but I recognize your name and you are obviously the xpert. Thanks for the thorough xplanation. Interesting , useful and informative.
Reply:Ok , now I get it. Besides the cost, Argon isn't as aggressive when cutting. The bottom line is , air is free and 20% Oxygen in air vs. pure Nitrogen  is a good thing for cutting. Thanks again for the great support.  Hypertherm has gotta be the way to go.
Reply:From another thread on this forum I learned:   the same way an OA torch uses Oxy to pierce metal is similar as to why a plasma torch is designed to use air (20%Oxy/%80Nitrogen) vs. 100% Nitrogen. The Oxy content is reactive to the metal and the acetalyne is only needed to preheat. In a plasma torch the Nitrogen is abundent, not  separated and provides pressure but; the Oxy still does the reactive metal piercing?
Reply:No....the 25,000 degree F. Plasma Arc does the piercing and cutting....the approximately 20% oxygen in air provides a small exothermic boost to the process....also chemically affects molten metal so it flows better. The results of air over nitrogen in a single gas plasma torch are: faster cut speed and less dross.Jim Colt Originally Posted by InsanerideFrom another thread on this forum I learned:   the same way an OA torch uses Oxy to pierce metal is similar as to why a plasma torch is designed to use air (20%Oxy/%80Nitrogen) vs. 100% Nitrogen. The Oxy content is reactive to the metal and the acetalyne is only needed to preheat. In a plasma torch the Nitrogen is abundent, not  separated and provides pressure but; the Oxy still does the reactive metal piercing?
Reply:I remember Joe had 2 old plasma cutters that were made in the 60's They ran off nitrogen bottles but they had there own power supply about the size of two tomb stones stacked on each other maybe a little biggerThe torches were about 2 ft long i think GE made them but i could be wrongThat was long a goThey were only used to cut aluminiumBacked my CATMA over your CARMA oops clusmy me  What would SATAN do ?? Miller Trailblazer 302 AirPakMiller Digital Elite  Optrel Welding HatArcair K4000Suitcase 12RC / 12 VSHypertherm PM-45Rage 3 sawRusty old Truck
Reply:Say Killdozered, it seems like the Nitrogen only would be dryer and better on consumibles but Oxygen chemically aids in the cut as Ive been told. Also, where I live its dry and static electricity (ionized air/plasma) happens most of the time so, do you think  a plasma torch would work better in a dry climate compared to a humid climate?
Reply:Originally Posted by InsanerideSay Killdozered, it seems like the Nitrogen only would be dryer and better on consumibles but Oxygen chemically aids in the cut as Ive been told. Also, where I live its dry and static electricity (ionized air/plasma) happens most of the time so, do you think  a plasma torch would work better in a dry climate compared to a humid climate?