Source of helium, argon, etc for science fair project
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R Radford
Feb 3, 2012, 11:50:06 AM2/3/12
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My nephew has asked me to assist with his science fair project (6th
grade), and we have settled on making an incandescent light bulb.
The initial idea was to use a small glass jar with a rubber stopper on top, and to pull a partial vacuum on it, similar to this link:
http://www.makershed.com/Reinventing_Edison_Build_Your_Own_Lightbulb_Kit_p/mkhe01.htm
However, in looking around at a few other sites, i have determined it would probably be easier to just replace the typical air with an inert gas than to try and pull a vacuum, similar to what is shown on this page:
http://www.livescience.com/7060-light-bulb.html
So, other than the disposable party helium bottles, does anyone have a suggestion of where I can get a small bottle of helium gas I can use for the experiment? The plan is to help him build it and then let him to continue to experiment (with the assistance of an adult) with various materials for a filament, documenting his results. So whatever we use, we will need it for about 2-3 months. One of those small bottles of helium gas we bled off of our large S/T tanks would be great if I knew where to get one (rent or buy).
But it really doesn't have to be helium - it can be another inert gas as long as it is NON-FLAMMABLE, and preferably lighter than air (makes it easier to displace the air in the glass jar).
We plan to start on this in about 2-3 weeks, so I have some time to assemble the necessary items - just looking for ideas now.
The initial idea was to use a small glass jar with a rubber stopper on top, and to pull a partial vacuum on it, similar to this link:
http://www.makershed.com/Reinventing_Edison_Build_Your_Own_Lightbulb_Kit_p/mkhe01.htm
However, in looking around at a few other sites, i have determined it would probably be easier to just replace the typical air with an inert gas than to try and pull a vacuum, similar to what is shown on this page:
http://www.livescience.com/7060-light-bulb.html
So, other than the disposable party helium bottles, does anyone have a suggestion of where I can get a small bottle of helium gas I can use for the experiment? The plan is to help him build it and then let him to continue to experiment (with the assistance of an adult) with various materials for a filament, documenting his results. So whatever we use, we will need it for about 2-3 months. One of those small bottles of helium gas we bled off of our large S/T tanks would be great if I knew where to get one (rent or buy).
But it really doesn't have to be helium - it can be another inert gas as long as it is NON-FLAMMABLE, and preferably lighter than air (makes it easier to displace the air in the glass jar).
We plan to start on this in about 2-3 weeks, so I have some time to assemble the necessary items - just looking for ideas now.
Christopher Gorski
Feb 3, 2012, 12:24:48 PM2/3/12
to ncnea...@googlegroups.com
Rodney,
How much are you talking about needing? If you're just talking about a few jars full of helium, it may be cheaper to go to the store and get a full balloon and bleed it. (Probably a nylon one, not latex--you can snip the end of the nylon one without it popping. You know the ones--the silvered nylon is what people call "mylar", though proper Mylar is metallized biaxially-oriented PET--closer related to a Pepsi bottle than those balloons.) At a buck or two a balloon, you can surely waste a bit before you get into gas bottle price range.
Having said that: If a proper cylinder is more practical, Praxair had a bunch of sizes and charged a reasonable price for rental--the old receipt I have from one of our S cylinders claims $58.25 for the gas, $16 for delivery, and regular tax, and I think they were only a few cents a day cylinder rental. And that was for the "S", and you could certainly get a much smaller one. Phone was 1 (800) 225-8247. They are nominally out of Sanford. You can ask them if they have any cheaper inert gases; I seem to remember the guy being reasonably knowledgeable last time I called.
If you need a regulator, it's the same for all the 'medium pressure nonreactive' gases--CGA-580 is the standard for that bottle type. Nat'l Welders has them, or I'll plug for American Brewmaster here too, they're about $60 for the 580 regulator (they'll call it a "nitrogen regulator" if you call them to ask about it--850-0095).
For that matter: AB also has nitrogen gas, which could work, but you have to buy the cylinder ($100 full). If you had an empty or could get one (same type as the helium bottles we had been using), they will tank-swap a 20 ft^3 bottle for about $13.
... I don't know how CO2 or N2 would do, for that matter--I would /expect/ it would be fine. CO2 may in turn be cheaper, though you still need a regulator (CGA-320) and a gas bottle. AB also does those, they will fill CO2 bottles on site for pretty cheap though again you'd have to buy the bottle, or they ALSO sell cartridges for about $16 a box (10x 16gram cartridges), and a little squeeze dispenser: http://www.americanbrewmaster.com/product_info.php?products_id=244 You can fit a tube in the end of that gadget and then just squeeze the trigger to release the gas. I don't know how much mixing goes on at the interface--I know it's not perfectly airtight. I also don't know how much air 16g displaces, but I bet you could do the arithmetic based on Google if you wanted to try that route (:
So, those are the two places I would check--Praxair definitely has noble gases; if N2 or CO2 would work American Brewmaster has them in town. Or for that matter, a third might be Nat'l Welders--their gas prices were higher but if you're dealing with this small an amount it MIGHT be cheaper than paying delivery. 544-9699, they have a site over by Brier Creek. I guess you can call around and price it out. And remember you'll need bottle, gas, and regulator, whichever way you go, and a bit of tube and hose clamp and you should make sure you know what size barb grows off the regulator so you can buy the vinyl tubing cheap (AB, Lowes, wherever...).
If y'all come up with a good mechanism for building light bulbs, let me know. I can't stand "soft-serve" fluorescent! (:
HTH,
--me
Oh, also: I should still have the non-regulator flow control bits we were using for launches. That may be pretty fast flowing for filling a tiny jar, but it might do... if you decide you need that I will go figure out where I stashed it. Good for 580 only, of course--which should cover you for helium, argon, nitrogen, at least...
Disclaimer, of course: I used to work for American Brewmaster. Or maybe I still do--I may still be on the books but I am never on the schedule anymore. But they're also a good shop that I liked as a customer both before and after my time of employment, so I do try to send 'em business when I can.
How much are you talking about needing? If you're just talking about a few jars full of helium, it may be cheaper to go to the store and get a full balloon and bleed it. (Probably a nylon one, not latex--you can snip the end of the nylon one without it popping. You know the ones--the silvered nylon is what people call "mylar", though proper Mylar is metallized biaxially-oriented PET--closer related to a Pepsi bottle than those balloons.) At a buck or two a balloon, you can surely waste a bit before you get into gas bottle price range.
Having said that: If a proper cylinder is more practical, Praxair had a bunch of sizes and charged a reasonable price for rental--the old receipt I have from one of our S cylinders claims $58.25 for the gas, $16 for delivery, and regular tax, and I think they were only a few cents a day cylinder rental. And that was for the "S", and you could certainly get a much smaller one. Phone was 1 (800) 225-8247. They are nominally out of Sanford. You can ask them if they have any cheaper inert gases; I seem to remember the guy being reasonably knowledgeable last time I called.
If you need a regulator, it's the same for all the 'medium pressure nonreactive' gases--CGA-580 is the standard for that bottle type. Nat'l Welders has them, or I'll plug for American Brewmaster here too, they're about $60 for the 580 regulator (they'll call it a "nitrogen regulator" if you call them to ask about it--850-0095).
For that matter: AB also has nitrogen gas, which could work, but you have to buy the cylinder ($100 full). If you had an empty or could get one (same type as the helium bottles we had been using), they will tank-swap a 20 ft^3 bottle for about $13.
... I don't know how CO2 or N2 would do, for that matter--I would /expect/ it would be fine. CO2 may in turn be cheaper, though you still need a regulator (CGA-320) and a gas bottle. AB also does those, they will fill CO2 bottles on site for pretty cheap though again you'd have to buy the bottle, or they ALSO sell cartridges for about $16 a box (10x 16gram cartridges), and a little squeeze dispenser: http://www.americanbrewmaster.com/product_info.php?products_id=244 You can fit a tube in the end of that gadget and then just squeeze the trigger to release the gas. I don't know how much mixing goes on at the interface--I know it's not perfectly airtight. I also don't know how much air 16g displaces, but I bet you could do the arithmetic based on Google if you wanted to try that route (:
So, those are the two places I would check--Praxair definitely has noble gases; if N2 or CO2 would work American Brewmaster has them in town. Or for that matter, a third might be Nat'l Welders--their gas prices were higher but if you're dealing with this small an amount it MIGHT be cheaper than paying delivery. 544-9699, they have a site over by Brier Creek. I guess you can call around and price it out. And remember you'll need bottle, gas, and regulator, whichever way you go, and a bit of tube and hose clamp and you should make sure you know what size barb grows off the regulator so you can buy the vinyl tubing cheap (AB, Lowes, wherever...).
If y'all come up with a good mechanism for building light bulbs, let me know. I can't stand "soft-serve" fluorescent! (:
HTH,
--me
Oh, also: I should still have the non-regulator flow control bits we were using for launches. That may be pretty fast flowing for filling a tiny jar, but it might do... if you decide you need that I will go figure out where I stashed it. Good for 580 only, of course--which should cover you for helium, argon, nitrogen, at least...
Disclaimer, of course: I used to work for American Brewmaster. Or maybe I still do--I may still be on the books but I am never on the schedule anymore. But they're also a good shop that I liked as a customer both before and after my time of employment, so I do try to send 'em business when I can.
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Jonathan R. Trappe
Feb 3, 2012, 12:57:26 PM2/3/12
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For my Helium tank, 20 cu/feet w/regulator I paid $147.16 at National Welders on Capitol in 2008.
Not sure if that included helium; I think it did.
So, I own that little bottle; not sure if there is any helium in it right now; I think there is. You can swap those bottles in and out at national welders. I am in the Philippines, so it is hard to give it to you. But, email me directly if you want to try to arrange to borrow it!
-Trappe
From: Christopher Gorski <cpgo...@gmail.com>
To: ncnea...@googlegroups.com
Sent: Saturday, February 4, 2012 1:24 AM
Subject: Re: [NCNS] Source of helium, argon, etc for science fair project
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