Do I need an oil-less air compressor for plasma cutter?

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Hi, do I need an oil-less air compressor for my new plasma cutter? I have the Motorguard M26 filter coming too, but can someone share their knowledge on air compressors...oil vs oil-less, and what filters to use if I end up with an oiled one?THANKS!
Reply:.........Last edited by T E B; 01-05-2012 at 10:29 PM.
Reply:Cons for oil-less. 1) no oil 2) usually run at 3x higher rpm 3) high rpm = more noise 4) less metal in pump less cooling.
Reply:i am thinking of using the disposable pre  filters that you use when you paint with an HVLP gun in addition to the filters on the tank and on the compressor.  in size they look  like about the 1/3 of a  small tomato soup can and are made of plasticbobs77vet/37ford4drEastwood digital TIG200HH190Lincoln Invertec 155sLincoln weldpak 100sears/craftsman (lincoln) 50a 240v buzz boxO/A rig Harris gaugesnexion cut 50 dxchicago electric (HF) 240v spot welder
Reply:all of what Jay said plus it won't last long before it turns itself inside out. put a moisture trap on your oil lube comp ahead of the m26 and stay faithful on draining the trap and you will be good to go. if you want extra do the disposable on the plasma inlet. get the ones that change color when they need to be changed. oh and be sure to crack the drain valve on the bottom of the comp tank periodically so water and rust don't fill the tank..225NT bobcatAEAD200LEScott 125mm175, mm252 w 30A, PT225mm211, TA 181iHyper Therm 380, cut master 529100X & XX, Digital Elite6 Victor setssmith little torch, meco midget kalamazoo band sawsteel max saw evoulution circular saw
Reply:Uh...  The oil in a compressor has nothing to do with quality of air that comes out of the hose.  Generally, I would say to make sure you DO have an oil bath compressor as they are generally more heavy duty, create more CFM and are much quieter. Originally Posted by SundownIIIDon't get me wrong.  They are just as ill informed about politics as they are about welding, they just post more on that subject.
Reply:Originally Posted by 37ford4dri am thinking of using the disposable pre  filters that you use when you paint with an HVLP gun in addition to the filters on the tank and on the compressor.  in size they look  like about the 1/3 of a  small tomato soup can and are made of plastic
Reply:Originally Posted by rlitmanI don't think the plastic bodied ones should be used at full compressor pressures, just HVLP pressures (like 30psi or so), but a Motorguard filter is ideal.  That should be plenty.....
Reply:No, and you will find that most oil-less compressors don't have the CFMs to keep up.A couple of notes.From my limited experience, oil-less compressors are quieter, but they are of lower performance.  First and formost you need a compressor that can keep up with your plasma cutter.  Stopping and waiting for the compressor to build a charge is for the birds.I run a total of 4 filters.   Filter the air coming into the compressor (standard dust filter), filter the air leaving the storage tank (simple filter with moisture trap) and then a combination simple filter + coalescing filter in front of the plasma cutter (after about 100ft of air hose on a reel).  While I can't say my consumable life is great, considering all the ugly, rusty metal I cut with it, it seems pretty good to me.My compressor is 30 year old Craftsman 30 gallon, real 5HP full oil.  I added a new drain (remote so I can drain it easily) and 100% new plumbing and regulators.  The only failure I've had has been the pressure/motor switch.  At 90PSI if feeds the 60Amp Hypertherm just fine.  The whole setup will comfortably cut 1" steel (slow, but steady) and more comonly cuts 1/4" and less like it was butter.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Originally Posted by blackmountainHi, do I need an oil-less air compressor for my new plasma cutter? I have the Motorguard M26 filter coming too, but can someone share their knowledge on air compressors...oil vs oil-less, and what filters to use if I end up with an oiled one?THANKS!
Reply:You know they do make dual filter systems for compressors.  I have one that first filters out oil, then the second filter traps moisture from water.  I got mine from McMaster-Carr. "Hey I didn't come to look and learn, I came to turn and burn.... If I can't light up, I'm gonna light out!"-JodyIdealarc 250 "Fatman"MM 252MM 211 "Little boy" Victor Torches
Reply:Originally Posted by 37ford4dri agree i wouldnt crank it up to 175psi, whats the max pressure you plan on using with your plasma cutter?
Reply:Originally Posted by Charleyhorse  I wonder if it would be ok to miter and weld this pipe where it will have to make a 90 degree bend.  Also if I could weld caps on the end of this big diameter section and just tap into the cap to reduce down to regular 3/4 pipe.  Or to be safe, must I buy a large diameter pipe threader?  I've checked around and so far nobody wants to thread my big pipe unless I purchase it from them....
Reply:Originally Posted by DSWNo, it's not a good idea to do this. At 125-175 PSI you have a pipe bomb if your welds fail. I'm guessing by asking the question you are not certified to weld on pressure vessels so skip this idea. A 2 or 3' length of pipe threaded at Depot or Lowes is a lot cheaper.Actually the pipe doesn't work really as a cooler per say. It works as an expansion tank, just like your main tank does. As gas pressure is released as it enters a larger area, the temp drops naturally. As the temp drops, the moisture in the air can condense and come out. A true cooler usually works by allowing the air to cool even at higher pressures. This is often done with a refrigerant or by allowing the air to pass thru smaller sections of pipe. The smaller the pipe, the more surface area to volume there is and the pipe can dissipate heat better. I've seen guys use alum finned hot water radiant heating pipe for this use. The idea being the copper is a better heat sink and a fan blowing across the fins will remove heat faster. Water is an even better cooler, but most times it's not cost effective unless you have a pond of spring to use as a  reservoir.One huge things very few guys do is drain their compressor tank regularly. that's a huge help to keep water out of the system. removing the standard petcock at the bottom and installing a 90 with a length of pipe and a ball valve to drain this easily will help greatly. Number one it makes it simple to drain the system. Number 2 it allows water to collect in the pipe rather than the tank. Pipe is easy to replace if it gets rusty, a tank is a bit more costly and won't take as much rust to damage.
Reply:Originally Posted by CharleyhorseI burned out a couple of oil-less compressors before I learned that they have a duty cycle, just like a welder. In a shop, the noise from an oil-less compressor also gets annoying after a while. I'm also getting ready to set up my compressor system for a plasma cutter.  I read online somewhere that to help get moisture out of the air system, install a 20 foot section of wide diameter pipe right off the compressor, maybe 1 1/2" to 2", slope it, and have a drain on it at the lower end.  This will serve as a cooler and will extract more moisture out of the air before it gets to the Motorguard.  I've got the big pipe in the scrap pile, but I don't have a threader die big enough.  I wonder if it would be ok to miter and weld this pipe where it will have to make a 90 degree bend.  Also if I could weld caps on the end of this big diameter section and just tap into the cap to reduce down to regular 3/4 pipe.  Or to be safe, must I buy a large diameter pipe threader?  I've checked around and so far nobody wants to thread my big pipe unless I purchase it from them....
Reply:Originally Posted by CharleyhorseLots of good advice and ideas here.  I'm a farm/hobby welder, not a pro. Since I've still got the tanks left from the oil-less compressors I burned up, it would maybe be easier just to rig up a second expansion tank in the line than to mess around with big diameter pipe.  However, as for the alum finned hot water radiant heating pipe, I've got some of that in the barn somewhere as well, so I'm gonna check that out too, that may work better and even easier than an expansion tank. I've got more options now, thanks. As for installing a pipe drain in the compressor tank, I've not heard of that one, but I'm gonna do it, it makes great sense.  Thanks!
Reply:Most plasmas that I have been around use 90 psig pressure to operate. Volume is the key more so than higher pressure. Increase your volume and a smaller compressor will do fine......might burn up filling up the extra space though.A young green pipe welder asked an old salt one day...How can I make the weld on the bottom of the pipe look like the top.......The old salt replied....Screw up the top......