Making an Air Tank?

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Hey all,Is it possible to weld up an air tank for an air compressor? 150 psi max... I see welds on tanks at the stores that sell them but wouldn't know where to start... do you use sheetmetal or steel pipe? How do you make the cap---- Mine would be easier as I don't want a round one- I want a rectangular one to fit against my back wall or side wall in my garage, heck if I made it from aluminum I could suspend it maybe--- as I have limited space but still want a big air compressor.I will be getting a used thermal arc 185 tig for this project and many others down the road I hope.Thanks!Andrew
Reply:There are others who can explain better, but air tanks are round for strength. A square or rectangle tank is dangerous, from what I have heard.Considering how cheap air tanks are, I'd just buy one.Last edited by Yamahammer; 05-01-2008 at 05:56 PM.Reason: misspellingRichard TerryMarine engineer.............  C'mon retirement!
Reply:don't do it! Federal law requires special certifications to build or repair pressure tanks. These laws are in place for our safety. An air tank full of 120 psi air can explode violently. you do not want that. Please tell me you wont.
Reply:Yes, you can build one out of pipe. You can buy weld caps to fit about any size of pipe. Should you? If you are an experienced welder it won't be a problem. From your post since you had to ask this question I would guess you are not experienced and recommend you don't attempt it. It could cause in serious injury or death.
Reply:Andrew, I hate to say this, but this is one of those things that if you have to ask, you shouldn't do it. Yes, tanks can be welded. You really have to know what you are doing. At 150 psi you have a little over 10 tons on one sq ft of the tank. 12" x 12" x 150spi / 2000lb. Round tanks can withstand this because they put the steel in tension like an arch. 150 psi is the equivalent of 330' of water stacked vertical on 1 sq inch.  Originally Posted by hpfiendMine would be easier as I don't want a round one- I want a rectangular one to fit against my back wall or side wall in my garage, heck if I made it from aluminum I could suspend it maybe--- as I have limited space but still want a big air compressor.
Reply:Not worth your life or anyone else's. Air tanks are one thing that I would never attemp to fabricate, no matter how good of a welder you are. Ironically most air tanks have welds that look like s**t, I'm sure they are well inspected and x-rayed before sale.Patriot Performance AutoLincoln Power Mig 255CLincoln AC-225 StickVictor Journeyman O/AQuincy QT-5 Compressor
Reply:Just buy a 20 Gallon Air Compressor and put it in a square box so it fits nice against your back wall.   Build a Barstool Racer at BarFlyRacers.com!
Reply:We got involved with a thread like this way back when..General consensus was don't do it..I would not Myself and neither should you..Much more dangerous than new exhaust manifolds.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapsterWe got involved with a thread like this way back when..General consensus was don't do it..I would not Myself and neither should you..Much more dangerous than new exhaust manifolds.....zap!
Reply:anyone coming to this forum wanting to know how to build an air tank doesn't know enough to be able to build an air tank.  that said... around here we use old propane tanks all sizes and other sources are truck and Rv salvage yards for air brake tanks...some with automatic moisture drains already
Reply:Originally Posted by wrenchanyone coming to this forum wanting to know how to build an air tank doesn't know enough to be able to build an air tank.  that said... around here we use old propane tanks all sizes and other sources are truck and Rv salvage yards for air brake tanks...some with automatic moisture drains already
Reply:thanks guys-I figured it was over my head but didn't think 150 psi was that dangerous- I would never even think of making a nitrous tank (1500psi)- we had an air compressor tank rust out and leak about a year ago and I gas welded it and my weld looked a heck of a lot better than the mig?? welds currently on there so I figured a tank wouldn't be that tough- also trying to justify my soon tig purchase with projects - glad I asked...Funny you should mention the attic- I have a ranch with a full attic and wanted to do this but my dad thinks if I could even get it up there (some sort of pulley rig I am thinking) it will shake the whole house... I then was thinking of fabbing up some sort of brace to mount it to the block fireplace chimney instead of the roof trusses to prevent this but then the square tank idea came to me as an alternate- oh well back to plan A.  FWIW 20 gallons will do nothing for me- I want to run air tools and run them well- At my dad's house he has a 20 or 30 gallon with a 15 gallon backup tank and it is worthless- we can hardly break lugs loose on our bobcat with a mac air gun rated at 550-600 ft-lbs with proper air.  I am thinking 60-80 gallon with a 5 hp motor and maybe a 2 stage pump if I can afford it.Last edited by hpfiend; 05-02-2008 at 06:30 PM.
Reply:150 psi is a bomb,,,,, do you use big air hose to the gun ???
Reply:As with a lot of things you can probably buy a complete compressor ready to go for less money than you can build one for. And it will be safe. Just remember to drain the water out of the tank regularly.
Reply:sure you can build your own.if you can answer yes to the following1. are you a certified code welder for asme pressure vessels ?2. do you have material that is less than 6 months out of the mill?3. do you have access to UT inspection equipment4. can you hydrotest to 4x working pressure both static and dynamicsurely you get the point.......there are a multitude of tanks out there on dead compressors. watch craigslist. there are 3 within driving distance of me right nownot counting the two in my garageinsert thoughtful quote from someone else2000 Thermal Arc 300GTSW 3.5 hours1946 Monarch 20 x 54 Lathe1998 Supermax 10x54 Mill2004 Haco Atlantic 1/2" Capacity Lasernot mine but i get to play with it
Reply:If you know what you are doing it is no problem to build an air tank for a compressor. The key is having the necessary skills. If your welds can stand a 60,000 psi hydro test then 150 psi is no problem. I've made a lot of those welds in the past, but I bought my compressor complete with the tank. If I had built it myself my $320 220 volt 100% duty cycle 60 gallon air compressor would have easily cost twice that. I got it at about 30% off on closeout.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:FWIW- I was not trying to save money by building the tank- I know tanks are cheap- I just wanted a tank that would fit in my 2 car residential garage without putting it in the attic.
Reply:Originally Posted by Patriot PerformanceThats pretty bad if even ol' Zappster won't weld it!
Reply:Originally Posted by hpfiend...I know tanks are cheap- I just wanted a tank that would fit in my 2 car residential garage without putting it in the attic.
Reply:Originally Posted by hpfiendthanks guys-I figured it was over my head but didn't think 150 psi was that dangerous- I would never even think of making a nitrous tank (1500psi)- we had an air compressor tank rust out and leak about a year ago and I gas welded it and my weld looked a heck of a lot better than the mig?? welds currently on there so I figured a tank wouldn't be that tough- also trying to justify my soon tig purchase with projects - glad I asked...Funny you should mention the attic- I have a ranch with a full attic and wanted to do this but my dad thinks if I could even get it up there (some sort of pulley rig I am thinking) it will shake the whole house... I then was thinking of fabbing up some sort of brace to mount it to the block fireplace chimney instead of the roof trusses to prevent this but then the square tank idea came to me as an alternate- oh well back to plan A.  FWIW 20 gallons will do nothing for me- I want to run air tools and run them well- At my dad's house he has a 20 or 30 gallon with a 15 gallon backup tank and it is worthless- we can hardly break lugs loose on our bobcat with a mac air gun rated at 550-600 ft-lbs with proper air.  I am thinking 60-80 gallon with a 5 hp motor and maybe a 2 stage pump if I can afford it.
Reply:Basically you have to size your compressor for the cubic feet per minute of air consumption of the tools you are going to operate. You can rig up a 500 gallon tank and if your compressor doesn't deliver as much or more air at the proper pressure as your air tool requires you will eventually run out of air. Ideally the compressor should be big enough to run your tool and be able to cycle on and off to cool. Air compressors generate a lot of heat. Look at it like duty cycles for welding machines. Some are designed for longer run cycles than others and are priced approperately.
Reply:I welded up a tank once for a guy. 2' sq and 3 inches wide. It didn't leak but the sides blew out like a big pillow and it held a lot more air. Scared the heck out of me when it buckled. So i wouldn't do it...BobBob WrightSalem, Ohio  Birthplace of the Silver & Deming Drillhttp://groups.yahoo.com/group/southbend10k/http://groups.yahoo.com/group/sawking/1999 Miller MM185 w/ Miller 185 Spoolmate spoolgun
Reply:i build pressure vessel all the time that said.if you have to ask don't  ,if made wrong thy can will and do go boom with out warringChuckASME Pressure Vessel welder
Reply:i have a 3 cylinder 2 stage pump and a 184-t 5hp motor with 80 gallons of storage, and running DA sanders and die grinders for extended periods (20-30 mins at a time, id do alot of body work on cars) i still run out of air.  But it will run my IR impact guns, ratchets, or any other air tools just fine, as long as i dont run them continuously with no break.  Its mostly the sanders and grinders that eat air, about 20 cfm at 90 psi at full load. look on craigslist in your area, i got a 60 gal upright, with a brand new high torque 184-t 5 hp, and the brand new 3 cylinder pump, magnetic starter, and wiring for 250.  The motor alone new is around 600...its not worth the time/energy/or safety factor to build one...
Reply:Is this the same drivethruboy54 who just bought a 5HP compressor with a 60gal tank off craigslist and ended up cutting the bottom off the tank?  Was asking the board whether he should paint it before or after welding it back together.  Then I hope, decided to scrap the whole idea after being advised against welding a pressure vessel.Just trying to get the story straight since there seems to be a similar posting under this same heading.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.you must be a real joy to know in person, the only time i ever see you post ANYTHING is to criticize othersand to answer your question im not sure what im gonna do with the tank.  Id like a fire pit for camping, but id also like a second air compressor.  if i can find another tank, ill make a fire pitif i cant, ill weld it back together, which i have no problem doing.  i understand you think im a kid with a squirt gun who doesnt know anything, but a stack of certs and all the things ive welded in the field (which are ultrasonicly tested) say otherwise.and by the way, there is a HUGE difference between welding a previously designed pressure vessel, and designing a square tank from scratch.  my question, in another post was a question about coating the inside of a tank to guard agaisnt rust, not about welding.  If i have a question about welding, i go to the books...
Reply:Yessirree,Thought I detected that same smell of BS in the air.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIYessirree,Thought I detected that same smell of BS in the air.
Reply:why bother making a tank like some said it doesn't cost much to buy a small compressor buy on and just use it as a backup tank sell the motor on evilbay think SundownIII may a good nose there Creative metal Creative metal Facebook
Reply:you got it sundown, everything i say is BSdont you have anything better to do?
Reply:sundown i have been lurking around here for years i just finally registered and pretty much the only time you post is when you are on the rag. calm down and try to talk to people like they are HUMANS.. honestly i think you should have been banned years ago. why dont you try to treat people like you want to be treated. PLEASE.................
Reply:Originally Posted by hpfiendFWIW 20 gallons will do nothing for me- I want to run air tools and run them well- At my dad's house he has a 20 or 30 gallon with a 15 gallon backup tank and it is worthless- we can hardly break lugs loose on our bobcat with a mac air gun rated at 550-600 ft-lbs with proper air.