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Post by nikeajax on Aug 18, 2016 10:17:09 GMT -8
Hmmmm, I'm curious now as to how a Healthways Goldie would do with its venturi-tube and all: I remember you, John, were talking about the later MR-12's that had the venturi tube were prone to freeze-ups in frigid waters... anyone with insight here? Ahem, DD... John!
JB
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Post by SeaRat on Aug 18, 2016 10:39:23 GMT -8
I am going to start a new thread on this subject, as the thread on the UDS-1 has "morphed" into this subject. I will be importing several posts that originally were posted there.
Technidiver started with this observation:
I followed up with this:
The post above was supposed to come in below this one, but I don't know how to do that; my. apologies, Jaybird. I will answer it a bit later (after lunch).
John
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Post by nikeajax on Aug 18, 2016 10:43:45 GMT -8
John, you beat me to this  ...  I'm working on a painting right now and well... JB |
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Post by diverdon on Aug 18, 2016 11:32:27 GMT -8
Hey JB, I have yet to use a DH reg while ice diving. But I'd love to try it. If I'm not mistaken Swimjim and perhaps some of the regulars that go to Fortune Pond did some ice diving there. Hopefully he'll chime in too. Seahunt Jerry has been around since the earth started cooling too, so if anyone had done DH ice diving he probably has. Though he doesn't like cold water anymore...
John, I remember that thread and the article claiming DH regs were freezing up, but IIRC they were old and perhaps unmaintained. I'd love to hear first hand from divers I know.
DD
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Post by SeaRat on Aug 18, 2016 13:20:10 GMT -8
Hmmmm, I'm curious now as to how a Healthways Goldie would do with its venturi-tube and all: I remember you, John, were talking about the later MR-12's that had the venturi tube were prone to freeze-ups in frigid waters... anyone with insight here? Ahem, DD... John! JB Okay, I'm going to try describing the problems of freeze-ups in diving regulators, and talk a bit about two-hose regulators (including the Kraken) and ice diving. While I have not dived under ice, I've done the next-best thing, diving in water with ice around the edges. I did this with an MR-12II regulator, and it froze up after only about ten minutes. The reason is that the MR-12II has that unique venturi tube from the chamber to the mouthpiece, outside the regulator body. It is therefore more prone to get colder in the water. Then there is the fact that water is directly on the lever system of the single hose regulator. For two-hose regulators, the mouthpiece is separated from the second stage mechanism, so that second stage stays dry. There is a non-return valve between the mouthpiece and the second stage mechanism. You can see this easily on the following diagram of the Dacor Model R-4 regulator, but it applies equally to all two-hose regulators.  Note that there is not only the mouthpiece non-return valve, but also distance between the source of water in the mouthpiece and the regulator second stage. This is not the case for single hose regulators, even today's modern ones. These single hose regulators need special handling to keep the demand mechanism as dry as possible before the dive. And therefore, even today's single hose regulators, even with teflon coatings (Dacor did that) on the mechanism to discourage ice from adhering to the lever and demand valve, are more prone to freeze-up than even the double hose regulators (if maintained well) of yesteryear. Here is a U.S. Navy study on single hose regulator freeze-ups: Now, concerning vintage and today's double hose regulators, they have a distinct advantage over the single hose regulators. Why? Because their second stage mechanism is dry. But, if not maintained, they can leak water into the housing, and that will lead to freeze-up too. The Kraken regulator, today's new regulators, have a distinct advantage over our "vintage" double hose regulators, in that it uses a plastic case. These cases maintain their shape over the years, and provide better water-tight sealing qualities than the U.S. Divers Company regulators. Dacor's double diaphragm have a good record of sealing, and have that second chamber that is air-filled on top of the main diaphragm that also keeps water from contacting even the demand diaphragm. But the Kraken regulator by VDH is probably the best bet for anyone wanting an almost freeze-proof regulator for ice diving, almost because even it can be compromised if a single hose regulator is attached as an octopus. That octopus could freeze up on demand in an emergence; it would be better to use a separate emergency tank with a separate single hose regulator than to use the Kraken, or vintage double hose regulator, with an octopus during ice diving. I would go so far as to say that the Antarctic expeditions should invest in the Kraken rather than use either today's single hose regulators or yesterday's double hose regulators. I have one regulator that I bought in the 1980s that is not prone to freeze-up, the Sherwood Maxim Blizzard. It has two copper vanes that travel from the top of the mouthpiece to the second stage valve which transfers heat from the diver's exhalation directly to the second stage mechanism, thereby preventing freeze-up. Here is a 1995 research paper on the performance of the Sherwood regulators with a heat-retaining plate: Because the U.S. Navy still could not endorse this approach, I still think that a new Kraken would be better than any single hose combination currently being used. John |
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Post by SeaRat on Aug 18, 2016 13:45:02 GMT -8
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Post by technidiver on Aug 18, 2016 16:01:55 GMT -8
I'll read this before doing anything with the Goldie. TD |
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Post by SeaRat on Aug 18, 2016 17:52:47 GMT -8
Technidiver,
You will have no problem with the Healthways Goldie (Gold Label Healthways Scuba regulator) in ice water. It is watertight, and the venturi tube Jaybird was mentioning is protected within the air-tight chamber. It should function well, as would the USD Mistral regulator. I just re-read Jim Thorne's chapter in his book, Occupation Adventure, where he recounts being the first Antarctic diver to spend half an hour underwater in November, 1960. He talked about taking two hours getting into his protective clothing (2 pair of long underwear under a dry suit), and using the gear. He has a photo that looks like it may be either a DA Aqualung or a Mistral regulator being used. The difference would be in reducing the pressure in one stage, rather than two, but that heat loss (from the decreasing pressure) would affect the outside of the regulator, not the dry inside. 'Hope this helps.
John
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Post by technidiver on Aug 18, 2016 18:42:50 GMT -8
That makes me feel better. I hadn't planned on diving under the ice, so it should work quite well.
Thanks John
TD
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Post by SeaRat on Aug 19, 2016 16:02:37 GMT -8
I have found a site which shows the extremes that the Antarctic divers go through to get their Sherwood regulators to work in Antarctica. It is a very interesting read. www.peterbrueggeman.com/nsf/fguide/scuba-diving.pdfI think this is the documentary that Norbert Wu videoed. John |
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Post by sitkadiver on Sept 13, 2016 12:09:03 GMT -8
Thanks for sharing that John, that was an interesting read. Living in Alaska, it has been my experience that the air in the tank hass just as important a role in regulator freeze up, as does the condition of the regulator. I have used air that was pumped on a 40 degree, rainy day, a week later in frozen sea water and my reg free flowed. The compressor I normally fill with has a very large filter and I manually drain the collectors every 10 minutes or so. When we were using the smaller compressor and the drains were not opened at shorter intervals, I found the water vapor seemed to increase in the tank. I only mention this becuase the table on p. 206 show the 1990/91 season to have a 20% increase in compressor fills. I have also removed my regulator to fill lift bags in sea water with surface ice and the single hose reg free flowed(Conshelf 20), but the double hose reg has not.(only tried this once with each regulator.) So, my conclusion from those two incidents is that the 2 hose reg, which stays dry, is better than the single hose reg, which is exposed to sea water when removed from my mouth. It's interesting that the RAM's were still being used in 1990. That is an amazing track record considering the RAM was last cataloged in 1975. The article states they were observing higher failure rates in conjuction with a lack of available parts. I can't help but wonder if USD was able to provide those parts or if they were going through a third party vendor. Another thing that I wish the article had addressed was FFM. It seems liek Antartica is a perfect local for an AGA or band mask. |
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I'm working on a painting right now and well...
