bigandy
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| posted on 21/8/10 at 07:34 AM |
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Oxygen.
Morning all.
Does anyone know a good source of those little Oxygen tanks that you used to be able to buy in places like B&Q. They were the ones that were to
be used with a propane tank of a similar size, in conjunction with a brazing torch. I think they had cylinders of Mapp gass too?
I'm after one for use in another project 
Andy
Dammit! Too many decisions....
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NigeEss
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| posted on 21/8/10 at 08:25 AM |
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There's a few on ebay, search for oxygen cylinder or bottle.
Time is an illusion. Lunchtime doubly so.................Douglas Adams.
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britishtrident
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| posted on 21/8/10 at 08:45 AM |
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As far as I known it is no longer available, I tried to get a cylinder from Halfords a few years back but the cylinders all had the wrong handed
thread for the oxygen adaptor.
For awhile a web shop called "The House of Hasting" were selling replacement kits of a new adaptor/regulator and a disposable bottle but
they don't seem to be around anymore.
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Daddylonglegs
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| posted on 21/8/10 at 09:58 AM |
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I have one of those mini brazing kits from Halfords, and as you say, you cannot get the oxygen anymore even though they still sell the acetylene
I did manage to get an adaptor to take another oxygen bottle which I sourced elsewhere though and it works fine.
I'll try and find the details as it's a while since I bought it.
JB
It looks like the Midget is winning at the moment......
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Peteff
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| posted on 21/8/10 at 02:34 PM |
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Welduk does a small oxygen cylinder here for £20.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Daddylonglegs
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| posted on 24/8/10 at 08:57 AM |
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Nice one Pete 
That's the one I was looking for, been so long since I ordered mine.
I got the adaptor too as the bottle will not fit directly onto the Bernzomatic head.
Works a treat 
It looks like the Midget is winning at the moment......
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Peteff
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| posted on 24/8/10 at 12:53 PM |
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I like to give him a mention, he's only 10 miles from me and I've nipped up for bits in the past but not been for ages.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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bigandy
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| posted on 24/8/10 at 01:12 PM |
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Ah, brilliant, thanks for that link Pete.
The regulator they sell will suit me too, as it has a hose tail aoutput. In case you were wondering, all this is for igniting a small Hybrid rocket
engine (40N.s total impulse).
Cheers
Andy
Dammit! Too many decisions....
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paulf
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| posted on 26/8/10 at 11:20 AM |
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If its a hybrid then you must be using nitrous oxide for the oxidizer and if I remember correctly the gas contained in the small oxygen bottles is
nitrous oxide rather than pure oxygen .
Isn't the normal method of lighting these to use a small solid fuel Estes type rocket motor pushed into the tail pipe?
Paul
quote:
Originally posted by bigandy
Ah, brilliant, thanks for that link Pete.
The regulator they sell will suit me too, as it has a hose tail aoutput. In case you were wondering, all this is for igniting a small Hybrid rocket
engine (40N.s total impulse).
Cheers
Andy
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bigandy
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| posted on 26/8/10 at 12:22 PM |
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That;s right, the Oxidiser for the main engine is Nitrous Oxide (and the fuel grain is currently a blend of wax/hotglue and iron filings to give it a
bit of sparkle, because I am a bit of atart like that ). Igniting the motors with chunks of Estes black powder motors is bloomin expensive though,
three Estes motors are not far off a tenner now.
So, I want to use gaseous oxygen to create an oxygen rich environment in the motor combusiton chamber, then use a high voltage spark to ignite the
fuel grain. Start the nitrous going, and away the motor goes My calculations show that a disposable oxygen cylinder (400ml size) will contain
about 120 litres of oxygen, so I reckon that will give me at least 100 ignitions, far cheaper than Estes motors
The idea is that once the little motor is proven, I can scale it up a little too
Andy
Dammit! Too many decisions....
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paulf
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| posted on 27/8/10 at 07:55 AM |
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Yes thats how i understood it to be working, what I was trying to say was I think the Oxygen in the disposable bottles is actually nitrous oxide or at
least it was in some of the smaller kits you could once buy.If that is the case then maybe you could just bleed of some nitrous at low pressure and
use that although it may not work if theres no heat to decompose it .
It sounds like an interesting project and is something ive meant to experiment with myself but never got around to.
Paul
quote:
Originally posted by bigandy
That;s right, the Oxidiser for the main engine is Nitrous Oxide (and the fuel grain is currently a blend of wax/hotglue and iron filings to give it a
bit of sparkle, because I am a bit of atart like that ). Igniting the motors with chunks of Estes black powder motors is bloomin expensive though,
three Estes motors are not far off a tenner now.
So, I want to use gaseous oxygen to create an oxygen rich environment in the motor combusiton chamber, then use a high voltage spark to ignite the
fuel grain. Start the nitrous going, and away the motor goes My calculations show that a disposable oxygen cylinder (400ml size) will contain
about 120 litres of oxygen, so I reckon that will give me at least 100 ignitions, far cheaper than Estes motors
The idea is that once the little motor is proven, I can scale it up a little too
Andy
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