Return-Path: Received: (qmail 83729 invoked from network); 27 Aug 2004 09:54:05 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore02.plus.net with SMTP; 27 Aug 2004 09:54:05 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1C0dQH-000PPW-O3 for dave@picks.force9.co.uk; Fri, 27 Aug 2004 10:53:31 +0100 Received: from [192.168.67.3] (helo=ptb-mxcore03.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1C0dQH-000PPS-KN for dave@picks.force9.co.uk; Fri, 27 Aug 2004 10:53:29 +0100 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1C0dQp-0003C4-6A for dave@picks.force9.co.uk; Fri, 27 Aug 2004 10:54:03 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1C0dQG-0000xX-BD for rs_out_1@blacksheep.org; Fri, 27 Aug 2004 10:53:28 +0100 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1C0dQF-0000xO-S3 for rsgb_lf_group@blacksheep.org; Fri, 27 Aug 2004 10:53:27 +0100 Received: from hestia.herts.ac.uk ([147.197.200.9]) by relay.thorcom.net with esmtp (Exim 4.41) id 1C0dQC-0007sB-IP for rsgb_lf_group@blacksheep.org; Fri, 27 Aug 2004 10:53:27 +0100 Received: from altair ([147.197.200.45] helo=altair.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 1C0dLa-0000wP-00 for rsgb_lf_group@blacksheep.org; Fri, 27 Aug 2004 10:48:38 +0100 Received: from [147.197.164.230] (helo=JamesMorrits) by altair.herts.ac.uk with esmtp (Exim 3.36 #1) id 1C0dLY-0004Hv-00 for rsgb_lf_group@blacksheep.org; Fri, 27 Aug 2004 10:48:36 +0100 From: "James Moritz" To: rsgb_lf_group@blacksheep.org Date: Fri, 27 Aug 2004 10:48:35 +0100 Message-ID: MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 X-UH-MailScanner: No Virus detected X-SPF-Result: relay.thorcom.net: 147.197.200.9 is neither permitted nor denied by domain of herts.ac.uk X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=no,HTML_50_60=0.183,HTML_FONTCOLOR_UNKNOWN=0.1,HTML_MESSAGE=0.001 Subject: LF: RE: Re: Gas for balloons Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_50_60, HTML_FONTCOLOR_UNKNOWN,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit

Dear David, LF group,

From what I remember of chemistry at school, 1mole of gas at room temp and atmospheric pressure occupies 22.4 litres of volume, and 1 mole of He weighs about 4g, whilst 1 mole of H2 weighs 2g. So a cubic metre of helium will weigh about 180g, whilst the same amount of hydrogen about 90g. Air is mostly nitrogen N2 at 28g/mole, so the air displaced weighs about 1250g. So the increased buoyancy of the hydrogen will only give 90g, about 7%, extra lift – ignoring the weight of the actual balloon itself.

What I would like to know is - what is a good source for the balloons?

Cheers, Jim Moritz

73 de M0BMU

-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of G0MRF@aol.com
Sent: 27 August 2004 10:06
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: Gas for balloons

In a message dated 27/08/2004 08:28:56 GMT Standard Time, g8cix@btconnect.com writes:

The latest Maplin Catalogue is now offering a gas cylinder and 30 balloons
for £39.

As a matter of interest you might like to know that one cubic meter of
balloon gas will lift one kilo.

Regards

Martin Maynard

Thanks Martin.

That's an interesting fact.

I had in mind something 'industrial' in scale - An advertising blimp etc.

Hence the interest in the industrial scale of the gas supply, but good to know from members of the group that balloon gas is widely available.

I wonder how the lifting capability of Hydrogen compares to the balloon gas?

It has several major disadvantages - small atomic size so it leaks quickly, not to mention the real posibility of re-creating the Hindenberg disaster. but it has the best lift capability.

Regards

David G0MRF