Plasma VS O/A

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I want a clean debate...I was under the understanding that O/A can indeed cut Aluminum and Stainless Steel.  Whereas, the Miller site says otherwise...So, what's the REAL scoop?  I just bought an O/A system, and am now having to think of a plasma cutter since Im interested in "welding arts", and would not be looking to cut anything over 0.5" thick.  Any advice would be much appreciated.ie:http://www.millerwelds.com/education...rticles60.htmlThermalArc 185MillerMatic 180 w/ AutosetVictor Cutskill Oxy/AcetyleneThermal Dynamics Cutmaster 38and spite!
Reply:The advantage to plasma for you would be the idea of having more precision with cutting. Stainless, alimuniu.... coppers.... can not be flame cut.That's the other plus... you can do those with a plasmaThe other thing.... if you buy a plasma buy one that exceeds your max thichness of 1/2". Look for a machine that will do 5/8" or even 3/4".As you get closer to the rated capacity of a machine the cut quailty will detiorate especially when being done by hand.Last edited by lorenzo; 03-03-2007 at 06:21 PM._________________Chris
Reply:Miller is correct. O/A sytems will not cut alum or s/s. You can melt either one into 2 pcs, but cut, no.
Reply:I know there was an old time method of flame cutting SS using a sacrificial plate of carbon steel on top of the stainless.  I have never tried it plus I cannot see the point of it since you would contaminate the stainless with carbon.
Reply:As mentioned above, you can not cut SS and Aluminum with O/A. The plasma cutter can do a better job than O/A for the most part for the type of application you are looking to do. I looked at both a short wile ago and went with the plasma cutter. Their were two main reasons for this. First- plasma can cut more types of material and better.Second- I have no need for O/A other than cutting, so rather than pay contracts on bottles each Werther I use them on not I decided to go with the plasma. One thing to note that a good supply of clean dry air is vital and a good ventilation system. When cutting with plasma allot of fine dust gets everywhere. And I do mean everywhere. Hope this helps.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:we have plasma and o/a in the shop. the only thing the o/a gets used for is my preheating and post heat, cutting out rusted bolts, heating stubborn bolts and such. the plasma gets all the cutting work. one of the mini o/a systems may work for pre-post heat and then get like lorenzo says, one that exceeds the 1/2" max you say."Retreat hell, were just fighting in the other direction"Miller Trailblazer 302, Extreme 12 VS, Dimension 400, Spectrum 375, HF 251D-1, Milermatic 251 w/ spoolgun  Hypertherm 1000Lincoln sp 1702000 F-450 to haul it
Reply:Originally Posted by lotechmanI know there was an old time method of flame cutting SS using a sacrificial plate of carbon steel on top of the stainless.  I have never tried it plus I cannot see the point of it since you would contaminate the stainless with carbon.
Reply:Okay, so by how much loss is there with running a plasma cutter when cutting softer metals?  ie: Alum, etc...Now YOU got me a lookin'.ThermalArc 185MillerMatic 180 w/ AutosetVictor Cutskill Oxy/AcetyleneThermal Dynamics Cutmaster 38and spite!
Reply:To give you an example.... my Miller 2050 is rated for 7/8" mild or stainless steel. On the aluminum side the capacity drops to 5/8".You may want to look at something like the ESAB Power Cut 650.... I don't know what they run for prices or what your budget is. When I was looking for my last cutter I tried the ESAB 1250..... and the Miller 2050..... I would have bought the ESAB to tell you the truth but I needed to find the biggest cut capacity I could while paying attention to the amp draw. This was being bought specifically for field work. The ESAB had a better price tag as well._________________Chris
Reply:Thanks, I'll be sure to look into it.  My dealer (Airgas) told me to stay FAR away from ESAB inverter welders, but told me the plasmas are where they know thier business.ThermalArc 185MillerMatic 180 w/ AutosetVictor Cutskill Oxy/AcetyleneThermal Dynamics Cutmaster 38and spite!
Reply:O/A will not cut non ferrous metals (the oxygen has to be able to oxidize the material), I own a 650 and am very pleased with it.  The torch is a bit hokey, but you get used to it.  Remember to get plenty of nozzles and a few contact tips (nozzles take a beating with plasma).  If you can swing it though, get a bigger one (the 650 maxes at 40 amps).  Good luck.Various GrindersVictor Journeyman torch200cf Acet. 250cf oxygenLincoln 175 plus/alpha2 gunLincoln v205t tigLincoln 350mpEsab 650 plasmaWhen you can get up in the morning, Its a good day.Live each day like its your last.
Reply:Originally Posted by DoolittleO/A will not cut non ferrous metals (the oxygen has to be able to oxidize the material), I own a 650 and am very pleased with it.  The torch is a bit hokey, but you get used to it.  Remember to get plenty of nozzles and a few contact tips (nozzles take a beating with plasma).  If you can swing it though, get a bigger one (the 650 maxes at 40 amps).  Good luck.
Reply:Let me start by saying I don't know much about plasma cutters except what I have read on the Forum.  But they sound like a great tool. The cost is hard to justify for a hobbyist so my question to you more experieced people is - what about the quality of the cuts in steel up to say 3/8 thick? Can you do cuts that are comparable to a plasma with OA?  I can get an OA setup for a fraction of the cost of a plasma cutter and have more versatility as well. Does it make sense to go this route if all I expect to cut is mild steel?  Thanks for your thoughts and comments."Don't confuse motion with progress"
Reply:Wonder if I could retrofit the 875 nozzel to work on the 650... hmm.Various GrindersVictor Journeyman torch200cf Acet. 250cf oxygenLincoln 175 plus/alpha2 gunLincoln v205t tigLincoln 350mpEsab 650 plasmaWhen you can get up in the morning, Its a good day.Live each day like its your last.
Reply:I forgot about something I read but never tried.  There is a powder (think its like what was mentioned earlier) that you can pile along you cut line that allows you cut nonferrous with o/a.  Think its just iron powder.  Probably looks horendous though.Various GrindersVictor Journeyman torch200cf Acet. 250cf oxygenLincoln 175 plus/alpha2 gunLincoln v205t tigLincoln 350mpEsab 650 plasmaWhen you can get up in the morning, Its a good day.Live each day like its your last.
Reply:Originally Posted by Ed WLet me start by saying I don't know much about plasma cutters except what I have read on the Forum.  But they sound like a great tool. The cost is hard to justify for a hobbyist so my question to you more experieced people is - what about the quality of the cuts in steel up to say 3/8 thick? Can you do cuts that are comparable to a plasma with OA?  I can get an OA setup for a fraction of the cost of a plasma cutter and have more versatility as well. Does it make sense to go this route if all I expect to cut is mild steel?  Thanks for your thoughts and comments.
Reply:I got a TD Cutmaster38. I LOVE IT! I've cut 3/4" steel with it, albeit very slowly. On thin stuff it's a dream, and you can drag the tip WITHOUT a drag shield on metal up to 3/16". I've cut ALOT of stuff with it so far, when I first got it I reduced alot of steel to random jigsaw puzzle pieces just playing around. I have swapped electrodes and nozzles once, but the first nozzle is in plenty good shape for things that don't have to be "perfect".Miller EconotigCutmaster 38Yes ma'am, that IS a screwdriver in my pocket!
Reply:I suppose it depends upon how fine a cut and in what material.  There's some nice O/A work in this thread http://www.hobartwelders.com/mboard/...767#post266767Good info on plasma cutters here http://www.millermotorsports.com/mbo...=plasma+cutterAnd here you'll discover not everyone is pleased with theirs http://www.shopfloortalk.com/forums/...=plasma+cutterHope you find this useful,Clay
Reply:For other than very low use or for heavy material plasma is the way to go. Running cost is less, and after you price out the monthly charge for tanks, refil cost, initial cost, etc of O/A, versus cost of plasma and electricity, you will see that  you don't have to be an industrial user to break aven in a year or to, but just a moderate user. Some home users will fall into that catagory where the finances make the difference, but probably most won't.If you want to cut anything but plain carbon steels, plasma is pretty much the best way to go. you CAAN cut other material with O/A, but you really don't want to. Crummy cut (even with the magic powders) and slow.