So basically to explain whats happening here, at high voltages any and all wacky chemical reactions can occur. Nitrogen is usually considered stable, but at high voltages can form nitrides etc, and NO2, aka raw smog. Oxygen burns the iron turning it into rust, releasing a ton of heat in the process. Also causes it to fly off as those sparks, as basically corrosion. Using argon means no oxygen, no extra heat, no corrosion, which is why its used as a shielding gas. CO2 has oxygen in it, and even though its also considered a stable gas, once again high voltages mean wacky chemistry, so the oxygen departs from the carbon, binds to the iron as usual, and the carbon remains as either CO (carbon monoxide, so be careful) or just raw carbon/soot which is why the metal appears blackened after the cut.
I came to the same conclusion re argon being inert. Oxygen being a very active oxidiser and Co2 being an active gas too. Im pretty sure oxygen would give you a pretty amazing cut.
I am courious as to what would happen if you increased the O2 in airup to maybe 40% or the CO2to 10 to 20%? one of the first rules ofor on the welding is to Never-Ever put oil on the oxygen tank cap threads or on the threads of the regulater or hose conections. If you reasurch "Medical Oxygen" (in tanks) you will find it is the same Four Nines (99.99% ) oxygen that is used for Oxy-Aceteline welding/cutting, just priced higher (likely because the tanks are suposed to be cleaned before refilling each time {probably to avoid any rust from damaging the equipment that feeds to the intended user/recipiant}) and because the suplier can. Portable oxygen (concintrators) don't like to say in their ads what the O2% of their units is but imply its the same as what you get from a tank truth is nither lets you breath pure oxygen but is just spiking the air above the normal 21%. Their adds often say they are "Creating Oxygen" instead of filtering out much of the Nitrogen. It seams that the people who are building & selling plasma cutters don't want to recomend any thing that strays from company policy. I would be very interested to learn if there could be an advantage to spiking the air with extra O2 or CO2? Would any inprovement in the cut be worth the extra consumable wear? What would MacGyver do?
Ya I want to try adding oxygen in small steps, maybe 5% at a time, curious to see what that dose, lately I haven't had the time to mess around with that tho but I'll get to it one day
From what I'e read, oxygen is a valid gas for certain plasma cutters... What I would be curious about though is using LPG since it is something that we can easily get refilled at any place that refills gas grill tanks... Maybe mix it with air in the right percentages so that you get a proper flame that would add heat to the cutting?
Ya I did some reading around too and hypertherm has a article about using different gases including oxygen. From what I gathered from that article tho it's only on torches that are degsined to use 2 separate gases, 1 for shielding and cooling and one for cutting, near as I understand it. I still Wana try tho increasing the oxygen concentration of air and using that. Lpg would be interesting to see out of curiosity but that doesn't sound like something I'm willing to try on my machine lol
@@tdm8817 -- 100 psi of LPG would probably result in such a high concentration of LPG that it wouldn't burn in the area of the cutting... But, it would flood the area with the gas and at some point, you have a lot of gas that has reached the right flammability concentration and a ready spark (the plasma arc) to make things "interesting"...
LPG would need to be run in a seperat line with flash back aresters to prevent an explosion. If air was spiked with CO2 or O2 or argon would cutting be inhansed enough to warent any consumeable exter wear?
