Buying o2

[Gavin Yates]

<font color='#000F22'>I'm supposed to read it &nbsp;... sorry I missed that bit. Nice one.

[steve-k]

Originally Posted by [b

Quote[/b] ]Surely anyone who dives Nitrox should have one of these, so it can't be considered an extra cost...

at our local diving shop/school and local clubs most people with a nitrox ticket dont have an analiser, if they get a mix then it is analised in the shop of purchsce


also i was under the impression that you did not own the cyilders and that you had to rent them?

Originally Posted by [b

Quote[/b] ]Given that Gavin is intending to fill his twinset with Nitrox, I think we can safely assume he'll be running mixes of less than 40%. Why then does he need more than one cylinder of Oxygen? He doesn't need high pressures

agreed to a point but when a j bottle is 1/2 empty you wont be able to get a 40% Mix in a twin12s, you are then left with the dilema of renewing a 1/2 full cyilder or being restricted with your mix, (not sure of the exact content and cant be arsed working it out, so please dont correst me)


but if gavin has all the equipment and fanceys a go then why not? there are more reasons for mixng your own than finantial

[Chris Hall]

Nice read so far, I have TDI blender cert &amp; own O2 analyer. Will help anyone if needed.

[Gavin Yates]

<font color='#000F22'>Nice one Chris.

I've got all the gear - minus the gas - and i've got a copy of the oxy hackers handbook and it all seems pretty simple if you follow a sensible approach.

What &nbsp;I think I could do with is a master class from a Scottish-based garage blender or are there any Scots on the boards that fancy splitting the cost of a few Js?

[parahandy]

Gav
Just had a look back at some blurb B.O.C. sent me a while back, when i used to take the o2 kit in for re filling at their depot.

Don't know if its current, but you used to hire the cylinders, very reasonable charge per month I remember the fill charge wasn't that bad. &nbsp;The down side was that there was a minimum transaction charge of £20 probably gone up.
The card they gave me says Medical Grade oxygen, with all the gen.

[Andy Winterburn]

Eh?
Surely the best way is to go into your local dive shop and see what they do, the type of kit they buy, the pipe work they run and the checks they do, the money spent is wasted. Or at least according to what I have read so far

Gav before you go killing yourself, or A N Other, give Andy Hayhurst a bell. For 48 quid and a days course he might just save your life.

With all respect I cannot believe some of the advice given. Sorry if this offends anyone BUT he might just do it you know.

[Dominic]

Originally Posted by [b

Quote[/b] ]agreed to a point but when a j bottle is 1/2 empty you wont be able to get a 40% Mix in a twin12s, you are then left with the dilema of renewing a 1/2 full cyilder or being restricted with your mix, (not sure of the exact content and cant be arsed working it out, so please dont correst me)

I did some quick working and concluded that you can get a decent Nitrox with about 75 bar left in the J. After that you're down to 50 bar and stuck to weaker mixes.
But since it takes about 25bar out of the J per fill, you'd still get at least 5 fills per J.
I don't think I can be bothered to work out if it's more cost effective to hire two at once to get the longevity or one and send it back partially full..

Originally Posted by [b

Quote[/b] ]before you go killing yourself

How exactly do you think he'll do that??
Mixing the wrong %age, Oxygen fire, or what?

[Gavin Yates]

Originally Posted by [b

Quote[/b] (Andy W @ Mar. 27 2003,08:10)]Eh?
Surely the best way is to go into your local dive shop and see what they do, the type of kit they buy, the pipe work they run and the checks they do, the money spent is wasted. Or at least according to what I have read so far

Gav before you go killing yourself, or A N Other, give Andy Hayhurst a bell. For 48 quid and a days course he might just save your life.

With all respect I cannot believe some of the advice given. Sorry if this offends anyone BUT he might just do it you know.

<font color='#000F22'>Andy - before getting on your high horse - read what I wrote on my opening post.

It has always been my intention to get certified for blending. I would do it any other way. Andy H would be my port of call as he is a garage blender supreme.

It's pointless talking to my LDS about partial pressure blending cos they don't really do it.

When folk starting talking about others killing people it puts them off posting for info at all. Thanks mate

[simon]

Guys,

You want to blend at home ?

you can get O2 from various places -

BOC- if you tell them its for diving they wont sell you it.

Air Products - They do their own DIVING GRADE, price £18 + vat and £8 + vat rental on cylinder, 200 bar

Lindy - They do DIVING GRADE if you haggel you could get it for £12 + vat @200 bar and £5 rental.But you tell them your usage and they deliver that every month.


[/b]but given that you only need 10 bar or so to get a 32% mix[b]

In fact you would need 27.85 bar of O2 for a 32%@ 200 bar mix.

I hate it when people assume things.

Gav its realy up to you if you think the cost is benifical, running two cylinders would be better than one, then you arnt sending it back with 40 - 50 bar in it , but its really pence.

Why not try and do a deal with your LDS,



Simon

[Dominic]

Originally Posted by [b

Quote[/b] ]but given that you only need 10 bar or so to get a 32% mix

In fact you would need 27.85 bar of O2 for a 32%@ 200 bar mix.

That's impressive - I managed to typo and misremember the amount at the same time
Meant to write 20 - I was going from vague memory as I couldn't be bothered to look it up.
The actual point still stands that you don't need high pressures of O2 to do backgas fills..