Plasma Cutter - Bottle for air supply?

admin

Hi. Considering a plasma cutter and was wondering can you provide the air via a large bottle? Like 125CF bottle of hydrogen? Is this practical?It seems like it would solve some moisture problems and be a little quieter.Thanks.Lincoln PowerMig 180cVictor O/ABandaids and aspirinI don't know what I don't know!?
Reply:Hello Skywest,Plasma cutting with a cheap inert bottled gas, such as nitrogen, works well; nitrogen is a commonly used alternative to compressed air.But hydrogen, being extremely flammable would probably not be workable.Good LuckLast edited by denrep; 03-16-2009 at 05:50 PM.
Reply:Originally Posted by denrepHello Skywest,Plasma cutting with a cheap inert bottled gas, such as nitrogen, works well; nitrogen is a commonly used alternative to compressed air.But hydrogen, being extremely flammable would probably not be workable.Good Luck
Reply:Hydrogen, Nope!Hydrogen + air/oxygen + heat = flame or BOOM!(notwithstanding some possible specialized industrial usage of monatomic hydrogen)Nitrogen as the gas = possibleCompressed air = usually the least expen$ive compressed gas sourceexample:  Hypertherm PowerMax30 specs say 3.5 scfm at 65 psi minimum, 4.0 scfm at 80 psi recommended, clean dry oil-free air or 99.995% pure nitrogen.That 125 ft3 pure nitrogen cylinder would only last for about 30 minutes of plasma use on the (smallish) referenced plasma cutter. Bigger machines have larger air/gas needs.To me, part of the charm and beauty of a plasma cutter is that it uses electricity and plain air from an air compressor.  Both of which I have or can usually get without all that much trouble.  Big tanks of nitrogen I don't have at my fingertips.    The best laid schemes ... Gang oft agley ...
Reply:Thanks for the replies.I have a 3 GAL 125PSI craftsman compressor. Is that enough.  (I forget the specs on it)I'm considering the HyperTerm 45.Lincoln PowerMig 180cVictor O/ABandaids and aspirinI don't know what I don't know!?
Reply:By the way - Not just should work, but for sure nitrogen does work for plasma.As I type this, in the shop there's a 100 amp plasma machine that's been plumbed to nitrogen bottles for years, and is ready to use anytime. I like it; crack the valve, throw the switch, instant dry air; and plenty of it. I don't believe the plasma machine is a big air-hog either. When I think of it, I'll try to see if the manual gives some CFM specs.If you're not running production, or if you don't have a large enough compressor available, nitrogen is a good alternative for many high air-demand jobs; such as - in the field carbon-gouging, or big-bolt tightening. But then again, -to paraphrase MoonRise- we do keep nitrogen bottles at the fingertips.Good Luck
Reply:Well I'm a home user, no production stuff in my near future. The thing I like about the bottle idea is the gas quality is great and for the price of a bigger compressor with filters etc> I could just get a big bottle of nitrogen and fill it a few times a year or whatever. That's my line of thinking anyway.RyanLincoln PowerMig 180cVictor O/ABandaids and aspirinI don't know what I don't know!?
Reply:Look for a used air compressor with a high cfm rating, 10 cfm or more.  The more air you give the plasma cutter, the better it works.   My 60 gal single stage shop compressor barely keeps up with it.  My 30 gal 2-stage gas compressor on the truck feeds it more air than it needs.  There are used compressors all over craigs list every day.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Post flow. If a machine has a postflow function then canned air as a sole source might be something to think about. Altho it's not much in the scheme of things if a guy was on a tight budget and trying to keep costs down it would be like change hitting the floor.
Reply:Originally Posted by skywestThanks for the replies.I have a 3 GAL 125PSI craftsman compressor. Is that enough.  (I forget the specs on it)I'm considering the HyperTerm 45.
Reply:Mag Mech....Sorry to disagree with you, but you couldn't probably cut more than 20 second cuts before running out of air with a 3 gallon tank.  Usually, these small compressors (pancake) are only about 2 cfm.  I think it would be hard to use a Hypertherm 45 very long with that kind of limitation.   I have a 30 gallon 150 psi, 5.7 cfm @ 90 psi and it still has a hard time keeping up with my 30 amp machine.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:2 CFM?uuummmm.That must be one of those thingys thats made to run a nail gun.His torch would never overheat.:A butterfly without wings, is just an ugly bug
Reply:3 gallon air tank and a 125psi max pressure on a little compressor?For a PowerMax45?You won't be happy and neither will the plasma cutter.  You'll both be frequently waiting for enough air from that little compressor.For my (mostly small usage) my 5.4cfm 200psi max compressor feeds my PowerMax30 just fine.  I don't think I've had to wait on the compressor when cutting at all.  I cut, the compressor may kick in, it usually cuts off while I'm repositioning the clamps or ground lead or cutting guide/straightedge.Cranking up the blow gun to 60-90 psi sure sucks the tank dry fast though!  Then the motor/compressor can't keep up with the air demand and I have to wait for the tank to refill.Get as big of a compressor as you can fit (space and $$$).  Well, maybe for a home shop and intermittent usage you can pass on the 50HP rotary screw compressor  , but you get the idea.  More air (rarely) hurts.Big nitrogen tanks will work as mentioned, but will be more expen$ive and have to be refilled compared to an adequate air compressor.Trade-offs man, it's all about trade-offs.    The best laid schemes ... Gang oft agley ...
Reply:Let's  assume that flow through the torch is 7CFM, that's probably high.300 cf cylinder  ÷  7 = about 42 minutes of cutting per cylinder.40 minutes of actual cutting is a lot.Good Luck
Reply:Actually, if I remember correctly many years ago, Nitrogen WAS the original plasma gas; we always used bottled nitrogen 20 and 30 years ago.   Even today, nitrogen being approx 80% of the atmosphere, it is what the plasma uses,,,,   just that the plasmas today are efficient enough to be workable with less than 100% nitrogen, thus the use of plain compressed air.
Reply:If you are going to run a portable plasma system off a compressed gas bottle.....use air. Nitrogen will work equally to air on Stainless and Aluminum.....but air will produce faster, thicker, nicer cuts on carbon steel.Air is roughly 75% nitrogen and 25% oxygen.....air plasma torches are designed to operate with this mix in mind, utilizing the exothermic reactions that helps to burn easily oxidizable materials (steel). Usually you can get a high pressure bottle of air from your local welding supply that is clean, dry and oil free...for less than a bottle of nitrogen.If you are just cutting sheet metal, use the smallest nozzle available for your plasma...as it will have lower flow. You can use the Hypertherm Powermax30 parts in a Powermax45 as an example.....make sure you do not exceed 30 amps...or you will quickly consume the nozzle!Jim Colt
Reply:I have run my Hypertherm 380 from my old Porter Cable pancake 150psi 4.x cfm @ 90psi compressor.   I had to spend alot of time waiting for the compressor to refill it's little tank and the poor pump ran constantly.  No fun, but it did work.   I don't think the pump would last very long if used that way alot.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by jimcoltIf you are going to run a portable plasma system off a compressed gas bottle.....use air. Nitrogen will work equally to air on Stainless and Aluminum.....but air will produce faster, thicker, nicer cuts on carbon steel.Air is roughly 75% nitrogen and 25% oxygen.....air plasma torches are designed to operate with this mix in mind, utilizing the exothermic reactions that helps to burn easily oxidizable materials (steel). Usually you can get a high pressure bottle of air from your local welding supply that is clean, dry and oil free...for less than a bottle of nitrogen.If you are just cutting sheet metal, use the smallest nozzle available for your plasma...as it will have lower flow. You can use the Hypertherm Powermax30 parts in a Powermax45 as an example.....make sure you do not exceed 30 amps...or you will quickly consume the nozzle!Jim Colt
Reply:With bottled air.....you will not need any kind of moisture trap.......but operating from a compressor you will. Winter in Colorado is relatively dry, but during rainy seasons and during humid summer....the humidity level in the air gets multiplied by the air compressor. A refrigerated dryer is best (HF, $350), dessicant dryers work very well, and there are coalescent type filters available that will also remove some moisture. A good rule of thumb....if your air system is designed like the air system for automotive spray painting (no moisture allowed)...then it will be adequate for the best performance of your plasma. Look at automotive supply outlets for the best deals on air filters, moisture traps and regulators.Jim Colt
Reply:Originally Posted by jimcoltWith bottled air.....you will not need any kind of moisture trap.......but operating from a compressor you will. Winter in Colorado is relatively dry, but during rainy seasons and during humid summer....the humidity level in the air gets multiplied by the air compressor. A refrigerated dryer is best (HF, $350), dessicant dryers work very well, and there are coalescent type filters available that will also remove some moisture. A good rule of thumb....if your air system is designed like the air system for automotive spray painting (no moisture allowed)...then it will be adequate for the best performance of your plasma. Look at automotive supply outlets for the best deals on air filters, moisture traps and regulators.Jim Colt