New propane tanks for air compressor

[ckucia]

Know a guy who might have a usable air compressor pump - something that would be on a 60-80 gallon tank normally. Have some old electric motors in storage and i think one might be around 5hp.

Seems I'd have everything needed to put together a decent air compressor except the tank and some pulleys.

Was looking around at new 60-80 gallon tanks - I figured since that's the one part that could explode maybe used isn't worth the risk.

Those tanks new are close to $500 plus shipping.

I recently bought some new 100lb propane tanks for our cabin. Those are about $125 each. They hold 23 gallons of propane at 80% filled, so if my calcs are correct, they're about 28 gallons a piece.

Could get three new ones at Lowes for $375 and have a little over 80 gallons of capacity. Thought I could mount them upside-down on top of a t-fitting so moisture would drain out through the fitting. Could also mount safety valving off a tee.

Is this a crazy idea or a great way to save a little cash?

 

[WhiffySpark]

I’d take the money and put it towards the kobalt 60 gallon compressor

 

[JamesW84]

Not sure about the logistics (sounds like it would work, though)but if it ever comes to resell, a proper tank would likely sell faster and for more money.

EDIT: I guess the propane tanks would still be propane tanks, so they might hold their value after all if sold as propane tanks.

 

[Bert_]

I've used them for portable tanks for years, they're great for that.

But if your going to spend $375 to get the same capacity as a $500 purpose made tank then I'd pass. You will eat up that tiny amount of savings buying extra tee's and fittings, not to mention the propane tanks won't have a plate to mount the motor / compressor.

 

[old__man]

Is this a crazy idea or a great way to save a little cash?

a) I think you won't end up saving any money after you get all the bits and pieces to 'make it work'.

b) It will probably not work as well and be as convenient to use as a purpose built tank

c) Something, and I don't know what, seems not wise about the whole idea. I don't know enough about propane tanks to know if they can store air (with moisture) long term at those pressures and those cycles.

d) Right now I can go buy a new 60 gal tank for $300 and I'm in Canada, where everything is always more expensive. I think you could find a tank for less than $500.

e) I like your creativity.

 

[58Yeoman]

Last year, I bought a new 60 gallon 5hp compressor at Menard's for less than $400. USA made Sanborn, same model I had since '74 before the tank sprung a leak.

 

[chaosracing]

I would just look on Craigslist or shop around. I bought a fairly new but used 80 gallon Kobalt for $350 off Craigslist. Since then, I have seen many other compressors listed for cheap. I would love a vintage compressor, but have no room right now.

 

[The Cobbler]

I would look for a proper compressor tank. years ago I would have agreed to the "propane tank route" but have learned that cheaper isn't always better.
you will have $375 in to the tanks, wrestle with getting the valves off, $30 worth of misc fittings , some sort of a stand to mount them upside down, they will take up more room and on and on.
toss in another buck or so to get a proper tank and you'll be happier in the end
princess auto here has 60 gal tanks routinely for $3 to $4 hundred

 

[apollo11]

Truly a bad idea

 

[ckucia]

Truly a bad idea

Can you elaborate?

Propane tanks are rated at a higher pressure than air compressor tanks (230 vs 200 psi). Using new ones voids the concerns of residual propane or the odorant. Mounting them upside down compensates for the lack of dedicated drain fittings.

About the only downside of propane tanks I can find is they aren't treated for corrosion to the same standards as dedicated air tanks, but they also are typically thicker than dedicated air tanks and have to undergo DOT certification. Were the vintage tanks in the used market treated to the same corrosion standards of today?

Not sure if I will use them, but in a small shop, I can see these being a lot easier to accommodate than an 80 gallon tank if you're tight on space and don't mind mounting the pump/motor frame elswhere from the tanks. I haven't measured them, but I'd guess you could fit 100lb propane tanks in between 16" studs and while not light, they're light enough you can get them up overhead easily. Can probably get everything mounted up high on the walls out of your way in less space than cabinets take up.

I see a lot of upsides and a few downsides for my situation, but there are a lot of different people with different situations and not every solution is the right one for everyone. OTOH, if there are real dangers here to consider, let's hear them.

 

[Bondo]

Ayuh,.... Ole propane tanks are Great for compressed air,....

I use this 1 when I need more volume than my compressor can make,....

 

[Farmall450]

Ayuh,.... Ole propane tanks are Great for compressed air,....

I use this 1 when I need more volume than my compressor can make,....

Yeah but I doubt you paid new prices (which exceeds a compressor as many before me have mentioned).

 

[GMCGarage]

Truly a bad idea

If buying new, they more than likely have not had propane it them, and how do the welds know the pressure is from air, not propane vapor?

What other issues are there?

 

[bob15]

If buying new, they more than likely have not had propane it them, and how do the welds know the pressure is from air, not propane vapor?

What other issues are there?

If it is a used tank, the air coming out might have that wonderful rotten egg smell for quite sometime.

 

[jimindm]

I kind of admire your resourceful thinking and wanting to do something that is sort of non traditional.

Many years ago when I was dirt track racing, many carried a large tank on their trailers for air. I would suspect many were propane tanks. That was before enclosed trailers and generators were common.

I suppose I would say I could see doing something like you suggest, if you could considerable money. I am not sure you will be able to do that.

While I have seen many talks like the one above, or even small tanks used as air tanks. What I do not know is if they are sort of unscrew fitting and screw what you need in. Would you be dealing with threads that are for the propane industry? Something you would kind of have to adapt, by making parts, or taking a fitting and making threads n it to work for you application.

Second you comment on the OP that you need pulleys. Does that include the large flywheel pulley for the compressor? I would think those are not cheap. Depending on age you may not even be able to get the one you need, and then you are dealing with a sort of make your own on it also.

All in all, I suppose you have to ask what your time is worth. As others have said, in the end you may only be saving a few dollars.

Some times it is not much of a cost savings to reinvent the wheel.

 

[Whitworth]

OP will need pulleys, V belts, tubing, fittings, regulator, switch, cord, a steel plate to mount this all to, preferably a shroud for safety, a dozen other things. All meaning, $$,$$$,$$$$,$$$$$$,$$$$$$$$ additional costs.

Complete waste of time, just buy a 5 hp compressor.

 

[larry_g]

The only suggestion I would make is that you start with one tank. If that proves to not support the work you do then add more receivers. Remember, the amount of work you can do in a day is determined by the size of the motor/compressor head and not the receiver size. Good luck with your endeavor.

lg
no neat sig line

 

[Firebrick43]

Propane tanks work perfectly fine as air tanks. No issues structurally. The Amish around here use 500 gallon tanks for air. Their wells, washing machines,fans,and many tools are air powered. Many have a windmill running a compressor to maintain incidental uses but nearly all have a small Diesel engine (normally a lister) running a jackshaft. Off of the jackshaft they run their milk chillers until the truck picks it up and when the chiller unloads after a cycle the air pump engages getting use from the engine while not under load.

I personally if wanting to save money would use a propane tank but would find a good used 125 gallon vertical pig and set it outside the shop. These can be found cheap although maybe not at this time of year. Mount the pump/motor on a plate and set it on a stand or heavy shelf to save floor space. I do question if any money would be saved by three new 100 lbs tanks and the stand/fittings let alone the floor space.

The mercaptan smell is mostly solved buy removing the valve and running water and soap through the tank for a day or two. Won't eliminate it but will greatly reduce it. After some time the smell will dissipate entirely.

 

[lakeroadster]

Is this a crazy idea or a great way to save a little cash?

Not crazy at all as long as:

• the tanks are rated for a MAWP above the pressure relief valve(s),
• the pressure relief valve(s) are the correct size,
• there are no shutoff valves between the tank and the relief valve(s) such that the tank can build pressure and the relief valve is shut off from the tank.

I do see some issues though related to piping. The relief valve needs to be up high so it won't see condensate. No problem in warm weather. But in freezing weather if the condensate in the lines freeze, the tanks won't work.

 

[apollo11]

pennywise
pound foolish

 

[maxpat82]

. What I do not know is if they are sort of unscrew fitting and screw what you need in. Would you be dealing with threads that are for the propane industry?

Propane tank use regular NPT thread/fitting.

 

[DpSyChO]

My local scrap yard gets in large air tanks from time to time. A 60 gallon came in a couple weeks ago. I saw it the day it came in, later that day after I got home I went to the mail box and saw that moles were making a mess of our yard and got to thinking that that tank could easily be made into an awesome yard roller as it had large (1-1/4 or 1-1/2 Npt fitting on each end. Went back couple days later with the truck and someone had already got it. If you have a scrap yard by, keep on the look out there for a tank. I've seen 80 and larger, maybe 120 tanks come into the same place.

 

[Zexx]

Main issue with using a propane tank for air is the lack of a drain.
If you have a used tank and want to use it for air, fill it with water (away from flames or sparks) to remove all remaining gas.

 

[Nor'Easter]

OP will need pulleys, V belts, tubing, fittings, regulator, switch, cord, a steel plate to mount this all to, preferably a shroud for safety, a dozen other things. All meaning, $$,$$$,$$$$,$$$$$$,$$$$$$$$ additional costs.

Complete waste of time, just buy a 5 hp compressor.

yep.