31 replies to this topic

[Kriterian]

I took my Nitrox class last night with four other folks at my local scuba shop Gypsy Divers in Raleigh, NC.

Two of the divers were buddies going on a trip to Bonaire that had free nitrox, another was a nice RN from a local hospital. The last person was the subject of this thread.

He was a nice, and very funny guy, from Romania. However, he plainly stated during the introductions that he didn't believe in Nitrox and probably wouldn't ever use it. Now I'm all for taking specialities for the heck of it, I may take the UW photography just to see if I like it. However, it struck me as odd that he would go through this non-diving dive training if he didn't plan to use it.

Everyone in the class immediately asked, "Why?", to which he responded that he was just taking the class as a stepping stone to trimix in the future. I know a little about trimix but I don't know enough to know if nitrox training is a requirement.

I was just wondering if anyone else considered it odd, or if it was the norm in some cases for people that knew they wanted to go straight into Tech diving? Also is there any link between nitrox and trimix?

[intotheblue]

Nitrox is a pre-req. to Trimix. You learn a lot about using alternate gases, calculations for dive planning and for use in deco planning (eventually)... (different because it can reduce the amount of N2 absorbed in your system, and because the elevated oxygen can be toxic at more restrictive depths). Your Romanian friend is a bit short sighted... as Diving Trimix is only a solution for part of the problems encountered with deep diving (assuming that is his goal). Nitrox is valuable in staged decompression necessary for most "deep" diving, as well as the use of pure O2. Sounds like an "ego" talking down the Nitrox in class... hopefully not. That kind of ego can be dangerous in the kind of diving he seems to be interested in. Hopefully your instructor will be good at instilling respect for "tech" diving.

Enjoy the Nitrox... it has benefits.

ITB...

[Diverbrian]

Actually, I do know of a few tech divers like this. They normally dive deep enough that EANx is of limited value in their bottom mix. Think about it: the advantages of nitrox below 140 ft. or so start to become limited. EAN26 isn't that much more effective than air. I will do it anyways as I will take any advantage that I can get though.

But, to go in with that attitude tells me that some instructor will have a "fun" humility lesson to give. Hopefully, this gentleman will change his attitude a little bit before going too much further.

ITB states the valid reason that nitrox is essential for tri-mix training. I just spent an hour last night planning my CNS and OTU exposures for various issues that could happen in my normoxic dives today (24/30 bottom mix with EAN36 and 100 percent oxygen for deco gases). Without Nitrox for deco gas, I double my deco time for the dive that I am doing (one of my plans had to be for complete loss of deco gas).

BTW, I am from the "I don't use straight air to fill my tires, much less breathe at depth" school. My nitrox training was done in conjunction with my OW training so I have been diving nitrox since after my second dive in OW training.

[Walter]

BTW, I am from the "I don't use straight air to fill my tires, much less breathe at depth" school.

Why?

[drdiver]

BTW, I am from the "I don't use straight air to fill my tires, much less breathe at depth" school.

What do you fill your tires with?

[randy54]

Heard a news story about this recently, that said tire manufacturers and tire shops recommend and use nitrogen. Oxygen is corrosive/explosive, and supposedly tires last longer and perform better.

[Walter]

So I should stop filling my tires from my tank?

[drdiver]

Heard a news story about this recently, that said tire manufacturers and tire shops recommend and use nitrogen. Oxygen is corrosive/explosive, and supposedly tires last longer and perform better.

Wow! I'd heard of people doing that in Brasil, but immediately thought it was weird--these are the people that waste good alcohol by burning it in their cars after all.

well, I don't think I drive fast and far enough for it to matter and I don't know where I could get it done anyway. I fill my tires from my tank, too. But I've never used EANx for that. LOL. But you know if you filled your tires with helium, your car might be lighter. LOL

[WillDiveForBeer]

Heard a news story about this recently, that said tire manufacturers and tire shops recommend and use nitrogen. Oxygen is corrosive/explosive, and supposedly tires last longer and perform better.

Wow! I'd heard of people doing that in Brasil, but immediately thought it was weird--these are the people that waste good alcohol by burning it in their cars after all.

well, I don't think I drive fast and far enough for it to matter and I don't know where I could get it done anyway. I fill my tires from my tank, too. But I've never used EANx for that. LOL. But you know if you filled your tires with helium, your car might be lighter. LOL

I think you meant to say your car would have less force and Kinetic friction on the ground, but not lighter. Yes, the helium atom is lighter than the air molecules we breathe, but that makes so little difference in the mass of your car. The same goes, which weights more, a pound of fat or a pound of muscle and 90% of the people will day muscle, which is wrong. Muscle is more dense than fat, but a pound is a pound.

To get back to tires, airplanes fill their tires with nitrogen, since regular air has water vaopr in it and when at altitude, regular air will "freeze" in the tires due to the water vapor. I wouldn't suggest filling your tires with EANx, as the extra oxygen will corrode your tires. One of the major erroding factors to tires is Ozone (O3), but as stated before, most of use wear out the treads on the tires before any use of a different gas mixture in our tires will reap any benefits on wear. As for racing a car with a different mixture, as far as I know, the racing circuits use regular air in their tires and if they are traveling 200MPH+ and it's good enough for them, then it's good enough for me.

[Walter]

I think you meant to say your car would have less force and Kinetic friction on the ground, but not lighter.

Actually, it will be lighter. You are correct, it won't be enough lighter to matter, but it will be lighter. OTOH, some bicyclists do fill their tires with helium.

I'm still wondering why Brian wouldn't breathe air on a dive. There are times when it's the best mix for the dive.

[In2h2o]

Heard a news story about this recently, that said tire manufacturers and tire shops recommend and use nitrogen. Oxygen is corrosive/explosive, and supposedly tires last longer and perform better.

There are people that fill their tires with 100% O2?? Probally been hitting too much N2O

O2 (by itself) is not explosive but it is corrsive and does increase the rate at which synthetic rubber breaks down (which is why Viton O-rings are used when diving Nitrox).

As for the use of Nitrogen to fill tires...aircraft use it b/c of low mostiure content, they dont have to worry about mostiure freezing inside the tires and race teams often use it out of conveience rather than due to any performance benefit. No compressor is needed to fill a tire if you have a bottle of nitrogen.

[drdiver]

No compressor is needed to fill a tire if you have a bottle of nitrogen.

Or a bottle of air..........

I think there is too much fascination with altering air. We evolved in air, we were born in air, we live in air, we will die in air. I like air.

[Diverbrian]

No compressor is needed to fill a tire if you have a bottle of nitrogen.

Or a bottle of air..........

I think there is too much fascination with altering air. We evolved in air, we were born in air, we live in air, we will die in air. I like air.

I like air too... at 1 ATA. At pressures above 1 ATA, I like nitrox or (later on in my diving career) tri-mix.

The air to fill my tires was not literal. It is just a way of saying that I don't have much use for the limits of straight air when I go diving when I don't have to deal with them. I did my OW on Nitrox 36. The dive shop prebanks EAN36 so they fill it in a manner similar to air. Approximately 99 percent of the time, I dive with enriched mixes. It drives me nuts to pay good money to diving and then have my dive cut short by a lack of bottom time available due to a leaner mix that I have to dive.

[Kriterian]

BTW, I am from the "I don't use straight air to fill my tires, much less breathe at depth" school.

What do you fill your tires with?

Whipcream! So he's always ready for the ladies

To remain on topic though:

Even on those deep dives below 140 ft, wouldn't you be using nitrox for deco anyway?

[Walter]

It drives me nuts to pay good money to diving and then have my dive cut short by a lack of bottom time available due to a leaner mix that I have to dive.

It drives me nuts to pay extra for nitrox when it won't increase my bottom time at all.

At 50 ft on EAN 40, my NDL is unlimited, on air my NDL is 1 hour 20 minutes.

At 40 ft on EAN 40, my NDL is unlimited, on air my NDL is 2 hours 30 minutes.

At 30 ft (or shallower) on EAN 40, my NDL is unlimited, on air my NDL is unlimited.

Why would you pay extra for nitrox on shallow dives?

I also dive air on walls. Unless there's a hard bottom, I don't dive nitrox. I plan my mix for the hard bottom or I pass on nitrox.