Propane tank

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David Nagy
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Propane tank

Post by David Nagy »

I would like to construct a fusor and I was wondering if a propane cylinder (empty of course) would be strong enough to be used as the vacuum chamber.
In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

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Carl Willis
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Re: Propane tank

Post by Carl Willis »

I'm sure the tank is strong enough to support an internal vacuum. In propane use, they are pressurized to ~100 PSI. Atmospheric pressure is only about 15 PSI.

There could be other problems that would render a propane tank poorly suited for a fusor vacuum chamber: the mercaptans used to odorize propane could penetrate the tank walls and outgas indefinitely; the metal surface may be porous; and in any case you'd be committed to using non-vacuum-standard techniques to add ports and fittings. There is no precedent for the use of a propane tank to make a fusor. It would be an experiment with a chance of being unsuccessful. Be sure to consider the recommended, tried-and-true alternatives, and be sure to consider the cost of getting a professional to add ports and fittings to any vessel you want to use.

It should go without saying, but enough people get injured by re-purposing supposedly "empty" propane tanks that a word of safety is in order. The tank is not "empty" even if the valve has been left open; it contains a potentially explosive mix of residual propane and air. Professionals purge these tanks with nitrogen before doing any work on them. Hobby metalworkers seem to be fond of filling them with water (perhaps in lieu of having a convenient supply of nitrogen) for the same purpose. Better make sure you have competent adult supervision before doing anything to an old propane tank.

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David Nagy
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Re: Propane tank

Post by David Nagy »

When I said empty I meant I would order a brand new never used propane tank. Would a high pressure gas cylinder work?
Last edited by David Nagy on Mon Jan 20, 2014 11:24 am, edited 1 time in total.
In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

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Carl Willis
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Re: Propane tank

Post by Carl Willis »

$500 is doable for a chamber...be sure to read the archives. The real problem is "with no support from my parents." Since you are 13 years old, chances are you rely on almost everything from your parents. Your workspace, your funds, your safety, your recreational time, not to mention your basic sustenance, flows from them. There is no guarantee they will support a fusor project, but your chances improve if you involve them in your aspirations from the very beginning and share your sources of background information. You need your parents to do this project, and you should also try to find a local mentor who can provide guidance on technical matters and safety. Getting parental buy-in ought to be your first priority.

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Chris Bradley
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Re: Propane tank

Post by Chris Bradley »

David Nagy wrote:.. if your such a genius tell me how I can ... afford the rest of the crap I need for the fusor?
Charming!

I'm surprised Carl continued to plainly answer your question, without indicating such hostility is not appropriate.

You will find something suitable on ebay for peanuts, but you may have to keep looking and wait a while. Simply, a large flange will likely do the job just fine.Start small and work up. See what works. Re-tasking a propane tank sounds like a waste of time, and $500 sounds like a waste of money.
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Re: Propane tank

Post by David Nagy »

You're right that was innappropriate of me but I was very stressed with the construction of this fusor and that no one in my family supports my efforts I am trying to build it purely from my money because they are not willing to help me.

My apologies for my rudeness I hope you can forgive me Carl.
In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

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Richard Hull
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Re: Propane tank

Post by Richard Hull »

Construction of a nuclear reactor is not a snap for anyone. It is this very challenge that makes this a very special effort and if carried to fruition a very special accomplishment. The more difficult the task, the more road blocks and frustrations are to be expected. This effort is a microcoom of life, itself; the greater the goal undertaken, the greater the challenges involved. Nothing worth bragging about is easy, especially if it demands multitasking, multi-level efforts from learning new things to learning new skills, coupled with hands on work and the comittment of one's treasure as well.

Good luck in your efforts

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
David Nagy
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Re: Propane tank

Post by David Nagy »

My parents said if I still want to build one in 3-4 years then I can but for now I have decided to build a 3d printer instead so I will probably not be as active on the forums.
In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

J. Robert Oppenheimer
Tom McCarthy
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Re: Propane tank

Post by Tom McCarthy »

Goodbye. Good luck.

Tom
randy baron
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Re: Propane tank

Post by randy baron »

In case anyone else is considering to use an old propane/gas tank as a vacuum chamber:

"Vacuum Chamber Build" by cecrops props, https://www.therpf.com/forums/threads/v ... ild.232006

It's not for a fusor but the guy does a nice job and describes some of his design considerations, which is always helpful to see.
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Re: Propane tank

Post by John Futter »

Randy
Some more reading on this site would have led to steel not being a very good material for high vacuum work.
Steel instantly rusts with water vapour from the air. This very slowly desorbs over many days making a good vacuum hard to get.
Steel that is used in high vacuum is usually nickel plated to stop this happening ---this now makes it more expensive than stainless steel
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Maciek Szymanski
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Re: Propane tank

Post by Maciek Szymanski »

SDteel that is used in high vacuum is usually nickel plated to stop this happening ---this now makes it more expensive than stainless steel
Good point, John but for other hand standard carbon steel has some advantages like very good machining and welding characteristics (not to mention the price). It can be polished to mirror finish which reduces water absorption and atmospheric corrosion (and when under vacuum there is not much oxygen to oxidize). And there is copper platting as alternative to nickel - worse, but inexpensive and easily doable at amateur level. Not a perfect vacuum material, but in some cases accetptable.
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Richard Hull
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Re: Propane tank

Post by Richard Hull »

Poor David Nagy....6 years ago he asked this question. Is he still here?
Heck, Chris Bradley was still posting back then along with Carl Willis!
Dave was like all such youthful aspirants, he had no money and it seems mom and dad were more than willing to fund his effort in 3-4 years back then.
Is he back busy at work on his fusor? Did he discover girls? Perhaps his mom and dad realized it was just a phase, allowing time to prove them correct.
Is Dave in college? Who knows?
Dave seems to have joined the ever swelling ranks of the "disappeared".
Dave, if you are out there, let us know what happened to the dream of doing fusion.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
keelan
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Re: Propane tank

Post by keelan »

As a fellow fourteen year old, who also has little money, and has been working on a fusor since I was twelve, and who relies mostly on time to slowly save for the expensive gear, may I ask how one attempts not to lose sight of the goal? I am just as enthusiastic as when I started but, I have most of high school ahead of me and I am financially limited. Should I countinue to just set small goals and wait until I have acquired the proper equipment? Or should I start looking for a sponsor?
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Nicolas Krause
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Re: Propane tank

Post by Nicolas Krause »

Hi Keelan,

I've been working on my fusor for a long time. I first started really pursuing it back in 2014/2015, over 5 years ago. In 5 years you'll be graduated from high school! I only completed my vacuum chamber this year, and I've still got a ways to go before I'm done. I think two things have helped me stick with it. The first is a switch in mindset, that just because I put a project to the side doesn't mean I'm done with it. I can always come back to it, in fact time away from a problem/project can be very helpful to actually solving it! The second is why I'm interested in building a fusor, early on I wanted just to achieve fusion, but reading and re-reading everything here on fusor.net I realized lots of people have achieved fusion. For a project to be interesting to me I had to have a motivation a bit beyond simply copying other people. That's when what really grabbed me was all the things building a fusor would teach me. That has worked hand in hand with being able to step back from the fusor and then come back to it. Right now I'm building a vacuum thermocouple gauge, it's a simple project, but it lets me hone my electrical engineering skills. I would suggest the following for staying on track with your fusor and maintaining motivation.
  • Firstly it's ok to take a break, you don't have to work continuously on something all the time, you can come back to it.
  • Secondly, look at the project as a way to learn new skills
  • Thirdly, in that vein, I often pick smaller or simpler projects if I don't have the money or know how to achieve something with the fusor immediately.
The first project that I completed was a small automated weather station that ran off a Raspberry Pi. It was very simple, and basically involved copying and pasting someone else's code, and getting it running, but it helped me understand how programming worked and what the basic steps were. Then I tried to make my own little heart rate monitor using an Arduino, both of these projects were not directly related to the fusor but they gave me useful skills and practical experience. When I was learning to machine metal, my first project was an aluminum die, and I made a small thumbwheel on a lathe. Again, these objects sit on my desk now, I'm not going to use them on the fusor, but without them I wouldn't have been able to machine my vacuum chamber. I'd suggest picking a small project that you find interesting, that has a skill you can apply to the fusor later on. The bonus with smaller projects is they're often quite cheap! Completing them is motivating in and of itself!
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Richard Hull
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Re: Propane tank

Post by Richard Hull »

Slowly but surely, step by step, skills are gained and owned forever. Each discipline is conquered one at a time. Nicolas is working much like myself back in1996. I met Tom Ligon and got interested in fusion within a fusor. I was 24 years younger back then being only 50 years old at that time. There was no online source for amateur fusion. No help... No guiding hand... No daily source of information other than books, reading and doing, making all the mistakes, ( some costly). At 50 I had indeed acquired a terrific number of skills as an amateur scientist and practicing electronics engineer. I needed many more before I mastered the fusor and did my first fusion in 1999. It took 6 more years and a fourth fusor before I went over 1 million fusions per second, (2005). It took that long for me at 50 with a good, well paying job to get to 2005. Take it from me and Nicolas, slow down and develop skills and read a lot. Nicolas points out how during his "rest periods" he was able to reorganize his thoughts, learn more and really figured out a path that suited him better than he had initially.

All the best in your future efforts.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
randy baron
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Re: Propane tank

Post by randy baron »

Richard Hull wrote: Mon Oct 12, 2020 3:53 pm Is he back busy at work on his fusor? Did he discover girls?
I know what a fusor is but what is this "girls" thing you talk about? Is there something more interesting than experimental physics and building things?
randy baron
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Re: Propane tank

Post by randy baron »

randy baron wrote: Mon Oct 12, 2020 8:52 am In case anyone else is considering to use an old propane/gas tank as a vacuum chamber:
"Vacuum Chamber Build" by cecrops props, https://www.therpf.com/forums/threads/v ... ild.232006
It looks like that link I gave above is unfortunately no longer in service but you can access it via the way back machine:
https://web.archive.org/web/20201129045 ... ild.232006
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Richard Hull
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Re: Propane tank

Post by Richard Hull »

Girls are a real thing in the scheme of the developing glandular system of the male as adulthood progresses. Countless billions fall victim to it each year.

Randy, please do not use the gray block quote feature. Its use is frowned on here. I have mentioned this to all newbies for years now. We are smart folks and can retain what we have read.

My "discovery of girls" and college has been a major destroyer of fusion dreams of many high schoolers who came here and were never heard from again. Money and parental negation is another factor in the disappearance of many younger Don Quixote fusion dreamers tilting at the fusion wind mill.

Many arrive here full of p--s and vinegar and post for a short while, then, Poof! They are gone. The reasons are many and varied. Girls are just one of the siren's songs that leave fusion hopes dashed upon the rocks.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Dennis P Brown
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Re: Propane tank

Post by Dennis P Brown »

Sorry, but I can't resist this thread; as one of the 'boys' that has 'hung around' I'll say it is almost as much fun as running a fusor but far less expensive, less dangerous (except maybe, one's ego getting hit from time to time) and a whole lot less aggravating.
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Richard Hull
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Re: Propane tank

Post by Richard Hull »

I find it a great place, too. You generally have a better class of people, and they are kindred spirits, both seeking knowledge and willing to share it. There also a far more variegated group of folks with many passions within science and mechanics.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Andrew Hawes
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Re: Propane tank

Post by Andrew Hawes »

I think I will try making a fusor with a propane tank. I just took an old 20lb empty tank and purged it. now i am going to take it to a friend who has machine shop grade equipment to help me cut it open.
I will keep you guys up to date on how its going and let me know if you have any advice or suggestions.
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Rich Feldman
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Re: Propane tank

Post by Rich Feldman »

Good luck! Let us know how it works as a vacuum chamber.
I believe it's thick enough not be at risk of sudden collapse by buckling.
It will develop rust inside after exposure to air with normal humidity.

Years ago I unscrewed the valve from a retired propane tank, exposing 3/4" pipe thread socket, for a hydrostatic pressure experiment that was never completed (tho' I made a high pressure sight glass).
How much extra water needs to be pushed into a full tank, to reach proof test pressure of 250 psi (17 bar)?
A careful SWAG says about 55 ml (0.25% of the tank volume).
2/3 of that is from elastic expansion of the bottle, with hoop stress around 20 ksi (140 MPa).
1/3 is from bulk compression of water.

p.s. this old thread appears to be in top percentile of view counts at fusor.net !
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Richard Hull
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Re: Propane tank

Post by Richard Hull »

In spite of the numbers of "look-sees", How many successful propane tank demo fusors have been inducted to the plasma club? I am pretty sure it is zero.
Same goes for neutron club. How many?
I think this speaks volumes for the success of those that were tempted by propane tanks. Such chambers sound tempting to those with no real budget.
Adapting the tank to view port, suitable electronic gauging, gas lines, HV input, etc., would require some heroics and machining/welding skills.
We just haven't seen this go much beyond the "can I use a propane tank" stage...
Big numbers at the front or input end of this quest, but zippo at the output where success is to be found.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Mark Rowley
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Re: Propane tank

Post by Mark Rowley »

Here's my propane tank fusor from 2003. Odd that I'm listed as a "guest". I had originally joined in either late 2001 or early 2002.

This tank idea was limited due to finances at the time. However, from my current point of view, the cavernous size of the chamber would've required a monstrous beast of a PSU, not to mention host of other issues. Could a neutron producing propane tank fusor be made, I contend yes. If I was to go this path again, using a cut down medical type oxygen tank would be my first choice due to it's smaller size.

viewtopic.php?p=55662&hilit=propane+rowley#p55662

Around the same time I also made a demo unit out of the top portion of an old diving tank. That thread seems to be gone or tucked away where I cant find it. If I can find the pics I'll post them here.

Mark Rowley
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