Personally for anyone wanting to fill there own ask for diving O2, it makes about £3 difference for a J cylinder and is certified as a breathing gas.

Do you have any names of dealers who will deliver to a domestic address, and charge about £23 for the full-size bottle of diving oxygen?

Getting o2 delivered is actually hard, I found, because the dealers claim their lorries won't carry o2 bottles on the same lorry as other gases. I live across the road from a pub which gets co2 gas deliveries all the time, but the company said it's far too much trouble for them to deliver o2 separately.

The good thing about welding oxygen isn't so much the price - there is no practical relevance to paying £20 v. say £60 for a huge bottle capable of doing one's entire annual airways flying requirement - it is the fact that welding supplies dealers are on every corner and it's easy to drop by with the old bottle in a trailer and collect the new one. I dread to think what my car insurance company would think of it ;) but the welding gear dealer doesn't care; he gets all kinds of body repair cowboys dropping in all day long.

PM me, you know the address and I will sort it for you.

Dive shops regularly mix nitrox, which is basically air enriched with additional oxygen, up to 50% (normally). Does anybody know whether they are able to fill your bottles with 100% oxygen?

Yes they can - the problem I found with all my local ones is that they spot a non-diver from miles away and they refuse to fill a bottle for aviation use. I did the BSAC course part-way but could not bu**!!!!! my way through this. One of them kept asking me for an oxygen handling certificate. In another it would depend which 16 year old kid was on duty when I turned up. Some shops do little o2 trade outside the UK diving season and don't carry the stuff then. One used to do it, and then the helpful man left.

Another problem was that the American portable aviation oxygen kit bottles have a U.S. "540" thread on top of their valves. This is also a dead give-away of you not being a diver. You can buy a 540 to BOC adaptor but it's normally a short stiff one, which requires the bottle to be held up high while being refilled from the (normally vertically standing) source bottle. The dive shops don't like doing this and I don't blame them - I like to be some distance away from the bottle being filled, but not so far I can't see the gauge. I refill mine via a flexible hose assembly made specially for high pressure oxygen, but if you turned up with one of those in a dive shop....

One solution, if you have a usable dive shop, is to get the bottles with a valve which has the standard diving thread on top of it.

All too much hassle. I wrote some details down - email me if you need more info.

Bose x - you have my email.

Thanks. I was mainly interested in the technical aspects but I am a diver and know that without the appropriate license, dive shops will not rent or sell you gear/air/whatever. However, if you show up with a pilots license with a high-altitude endorsement, explain the situation to the owner etc. and generally be honest and professional about your intentions, and obviously bring the correct adapters, I'd say there's a fair chance they'll help you anyway.

In fact, what I would do is pay a visit to my local dive shop beforehand, without the bottles and things, and have a chat with the owner about it. See what he thinks about it, set up an agreement about the way it's going to be done.

After all, there is no *legal* requirement for dive shops to check your license. It's just that as a matter of keeping the sport safe, dive shops all over the world have agreed that they will not help customers without checking whether the license someone has is compatible with what they're buying. They will not fill your bottles with air unless you have a basic divers license (PADI OW, for instance), will not fill your bottles with nitrox unless you have a nitrox license etc.

Anyway, the highest I've been to so far in my aviation career is FL55 (and 32 meters in my diving career), so who am I to offer expert advise on this?

Having handled gas for 20 years I make a variety of adaptors and will fill any bottle. Most dive shops will fill a cylinder for you if you turn up with the correct adaptors for the cylinder. It is simple to make a whip for a CGA450 to SCUBA DIN477 fitting as it is for a bull nose to CGA 540 (O2 J cylinder). It is also simple to make an adaptor for converting a CGA540 to DIN 477 so the SCUBA shop can attach the filling whip direct to the cylinder.

The main problem occurs because the US cylinders are DOT standard cylinders and are not CE approved. This causes a problem for any gas filling station filling a non CE marked cylinder (despite them being the same cylinder with different paperwork). Another example of the problems caused by trying to bypass Europe....

However if you come prepared with the right adaptors and tell them it is an O2 kit you will get it filled. I will fill any cylinder provided it is in test to whatever the max working pressure is required (I have a gas booster). An average aviation O2 cylinder is about a fiver to fill.

All of the Mikes Waterfront Warehouses around the UK will fill an O2 kit as well if you have the adaptors. If anyone has a problem PM me and I will make a call.

I'm lucky enough to have plumbed-in O2, but having experienced a complete failure of the system (very high and over the worst sort of terrain for this to happen - ain't that always the way!) I think I'd like to get hold of a portable supply or two.

So, can anybody recommend one ?

Thanks !

FF :ok:

PM me.....

I've sent you an email, FF. Personally I use an Aerox system, since 2003. I think the Mountain High kit has better fittings. I decided against using its electronic demand regulator because they confirmed (at Aero 2007) that it fails SHUT when the battery goes (despite others claiming otherwise). Currently I use Nelson mechanical demand regulators; they seem to work OK, but if I was doing it from scratch I would go for MH. The only thing I don't like about the basic MH kit is that their bottles don't appear to have the pressure gauge on the bottle valve so you can't tell how much is in some bottle you have just picked up.

They do down here :) I don't dive as such but have a 3ltr pony bottle i use to clean my boat and get it filled from the shop.

Yes, yes, I know highly dangerous and all that....but I am very careful ;)