heliox

[omar]

I don't go to a shop for Tmx.

I have 10 year leases on the bottles which comes out to ~$9.00 yr/bottle for the He and O2 (2 bottles each). Filters for my compressor, grade E and hyperpure ~$250 to $400 yr and synthetic oil ~$25.00 year. All of this comes out to 3-5 cents per cuft depending on how much I dive.

The equipment is a legitimate tax deduction for me. And I can sell if/when I decide to quit. So I will break even on it in the long run. I don't need training to pump Tmx. I don't need to get some silly shingle from one of the agencies either to pump my gas. The only worthwhile training is the PSI cylinder inspection course.

omar

 

[padiscubapro]

Originally posted by omar
I don't go to a shop for Tmx.

I have 10 year leases on the bottles which comes out to ~$9.00 yr/bottle for the He and O2 (2 bottles each). Filters for my compressor, grade E and hyperpure ~$250 to $400 yr and synthetic oil ~$25.00 year. All of this comes out to 3-5 cents per cuft depending on how much I dive.

The equipment is a legitimate tax deduction for me. And I can sell if/when I decide to quit. So I will break even on it in the long run. I don't need training to pump Tmx. I don't need to get some silly shingle from one of the agencies either to pump my gas. The only worthwhile training is the PSI cylinder inspection course.

omar

No you don't need a trimix card to pump your own gas but you do need a certification for those trips that require you to prove you have the training before allowing you to dive with them.. many of the boats off ny/nj nowadays are limiting certain wreck trips to CERTIFIED mixed gas divers..

 

[omar]

I was talking about blending. I don't need the PADI gas blender certification or IANTD or CMAS or NAUI or TDI or............

I know that some boats require Tmx certification for some dives (as they should). I also know that they have some ludicrious requirements as well. Such as a pony bottle of air, jersey uplines, all round bottom tanks must have boots to name a few off the top of my head.

omar

 

[padiscubapro]

Omar,
If you are going to pump gas for others besides having some liability insurance you should also have some type of gas blending certification. Not that it will make an experienced blender any better, but if it comes time to defend yourself in court. You'll need to prove you know how to do it right. If someone dies or gets hurt on something you blended you'll also need a mix logbook showing it was analyzed because if the mix is different than stated there is a potential problem (or if you gave the mix to someone who wasn't qualified). Haven't you ever seen a tank that leaked He but when diving air/nitrox was fine... I was diving in Cayman last year and we blended a mix that was 18/50 when I re analyzed it the next day the o2 was 25% this could have been a serious problem since the dive was planned for 200 with tables for a contingency for up to 220... The He analyzed out to 43%, we tried a leak test and couldn't find anything.. after adjusting the mix and diving, we tightened down the burst disks and manifold, the rest of the week was fine.. If I wasn't so dedicated to always checking my mix before I dive it even though it was fine the day before I could have become a statistic. When they would have checked my tank it would not have been what was labeled and they would have started looking at the blender...

 

[roakey]

blacknet,

Not hostile, very, very confused.

Let's try a nice, neutral post.

From what you stated -- "...someone please tell me the conclusions stated in USN research report 7-58" I have no idea which side of the statement "He ls more risky in terms of DCS" it comes down on.

I don't understand why it was brought up in the first place if you're not sharing the conclusions it came up with.

So, a nice explicit question: What does USN research report 7-58 have to say about He and DCS?

Thanks in advance.

Roak

 

[blacknet]

roakey,

Being neutral here, have you read it and/or know what it states?

Ed

 

[roakey]

Originally posted by blacknet
roakey,

Being neutral here, have you read it and/or know what it states?

Ed

What an utter and complete waste of peoples' time and board space.

Let me see, would I be asking about something if I already knew it? Trick question, right?

Tell you what, Ed. I've asked for just what this document states three times now (feel free and go back and count) and all you've responded with is the game “I've got a secret.”

You know, the game has lost its luster since elementary school.

Obviously you don't think the information is important enough to post. I'll accept your decision on that matter and won't ask a fourth time. I was the only person that asked you what the document contained, I would have considered that an opportunity to post pertinent passages that addressed the He and DCS question.

But I’m no longer interested. You have (quite successfully I might add) made it much too painful to ask, for a fourth time, what the document says.

May I suggest next time you simply choose to educate.

Roak

 

[Lost Yooper]

I agree with Omar and PSP. The cert. cards are bogus, but I would only fill for myself and people I genuinly trust due to liability issues. I don't generally do deep stuff on my vacations, so I could care less about all the certs. You just have to try and talk someone into filling for ya who is of "like mind" (good luck to me anyways).

Ed, what the heck does the reports say for goodness sake? I don't have a clue and barely care due to the fact that it's ancient history. I think we have learned more about the decompression physiology of helium mixes in the last ten years than the rest combined. It would, however, be quite interesting if someone way back then knew (or had foreseen) the advantages of helium (besides the lesser narcotic effect).

Mike

 

[omar]

I blend for myself and a couple of diving partners. I don’t pump for money and even if I did, I do not need a blender certification. I can demonstrate that there are errors in the IANTD and TDI manuals on blending and I know who wrote the majority of the IANTD manual. I have not looked at the PADI manual. My undergrad engineering degree included P Chem. which covers in a much more useful and thorough manner the behavior of real gases. So there would be no problem for me to demonstrate that I understand and can blend correctly. In fact, I probably have one of the more comprehensive (as far as the ability to mix AND analyze) blending setups around and I log all of my blends anyway.

The helium leaking from a cylinder is typical dive industry BS. It will not leak preferentially from a mix. If you lost gas it will be in equal proportions to what is in the mix. I have a K cylinder of UHP Helium (which costs a fortune) I use for calibration purposes and as a carrier gas. I leave the regulator on it and it will sit for a couple of months unused in some cases. The use is logged for billing purposes so I would know if it has lost any gas. It has never happened. Heck if you get gas from a supplier you would know that it comes in steel cylinders that are for the most part the equivalent of a scuba tank. You can let these tanks sit for ever and you will not lose gas.

I also store in HP (4500 psig) cylinders 30/30 and 20/40, my 2 most used blends for local diving. I do not see a change in the mix over time and I have never seen any changes in my scuba tanks that have sat for long periods with trimix in them.

You can send an e-mail to Tom Mount at IANTD and ask him what he has found about leaving Helium mixes in scuba tanks for extended periods. It is the same - no loss of helium. Helium will not preferentially escape through a tank.

omar

 

[WetDane]

Ed,
I think you are hitting a soft spot there - there si a cost involved and although Omar has good $$$ on cusom mixes, I know that around here it is more like $50 for a set of LP104's, a 40 w/ 50/50 and the argon bottle...

It is also worth pointing out that there is a substantial amount of training required for this - although GUE resently conducted the first "rec" trimix class and obviously you have to look pretty hard to find the shops who have the equipment and knowledge to mix these things.

However - it is a very interesting question.

Big T