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Argonaut Kraken exhaust loop flooding issue...?

Discussion in 'Vintage Equipment Diving' started by Fibonacci, Oct 5, 2018.

  1. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    537
    442
    63
    With exhaust loop flooding or wet breathing?
     
  2. TN Traveler

    TN Traveler Loggerhead Turtle

    # of Dives: 500 - 999
    Location: Knoxville, TN; St Croix, USVI
    1,410
    300
    83
    Both. Made a recent liveabord trip much less enjoyable. Had done about 20-25 dives with it before the trip and had not seen the problem.
     
    Fibonacci likes this.
  3. SurfLung

    SurfLung Nassau Grouper

    # of Dives: 200 - 499
    Location: Central Minnesota
    95
    99
    18
    I'm probably going to irritate some of you with my comments but it pains me to see this post going on and on over what appears to be 2-3 people experiencing an occasional wet breathing double hose regulator... for whatever reason. Some even considering amateurish design changes as if the Kraken isn't the state-of-the-art double hose regulator that it is. I have three Argonaut Krakens and a bunch of other double hose regs that I dive 40-50 times a year. I dive with three other divers who own Krakens and they work great for all of us. But, you can't dive double hose regs without having some wet breathing from time to time. Cripes, in the old days they didn't even have one-way valves in the hoses like we have today.

    Exhaust loop filling up "glug glug"... Thats gotta be a big hole somewhere not a defective design. If its a trickle, its a small hole somewhere. Plug the exhaust, submerge the loop, and blow so you can see where the bubbles come out. Do you suspect the exhaust mushroom valve? Take the hose off and suck on the horn. If the mushroom is leaking, you'll suck air. If not, you'll suck nothing.

    General wet breathing... That's a different issue and it has a whole bunch of possible causes. Pin holes in the hose, loose hose clamp, debris under the mushroom valves, hole in the diaphragm, loose diaphragm, improperly sealed diaphragm, slipped (from lubricating) diaphragm... DSV half open, DSV damaged, etc. etc. I once mistook my own ice cold drool for a leak. Yeah that's gross but it is an aspect of double hose breathing. Again, nothing that needs amateur re-design... Just find the source and fix it.

    The reason I take issue with a forum that just keeps beating a dead horse issue like this is that it is unfair to the reputation of the product as well as the company that risked so much to bring it to market. I know its fun to discuss things you're interested in and get other people's opinions... I like to do that myself on forums. But I would bet 99% of the people who own Kraken regs either don't have this problem or figured out a solution logically and are very happy with their regs.
     
  4. lexvil

    lexvil Loggerhead Turtle

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    1,414
    935
    113
    Surflung, try reading every post rather than acting like someone stuck their dirty finger in your pie! I had this issue from the beginning and sent it back to Bryan who couldn’t duplicate it yet happened again and again, not every breath but every dive and with whatever hose is on it, or should I say which ever set of hoses I have one it, just to avoid the nit! It’s an intermittent problem but pervasive enough that I haven’t bothered diving the kraken in months.

    My kraken has been through a lot, if you read the posts you would know that my exhaust issue has been persistent since new, it may be a combination of how I dive and a component not working well together, as discussed earlier.

    This post is far from beating a dead horse, it’s been months since people have tried various cures and some ideas may be working which brought it back to life! If you don’t have the problem great but for those that do it matters, denying the problem won’t fix it.

    I started with DH regs and the Kraken is vastly superior to anything from the past but just because it’s better than a Mistral doesn’t make the flooding exhaust ok, most of us here are just trying to find a fix and pretending it’s not a problem doesn’t help.

    You were right about one thing, it seems you did piss someone off and now this will draw a lot of negative attention.
     
  5. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    537
    442
    63
    @SurfLung as I have said before, and will say again clearly...
    I admire Bryan Pennington's passion and tenacity in funding and getting the Argonaut Kraken modern double hose reg into actual production... often against all odds.
    While an experienced single hose diver I am new to double hose diving and still getting used to some of the differences involved in diving one. When functioning properly I very much enjoy diving my Kraken!

    HOWEVER like @lexvil I have experienced persistent and major exhaust loop flooding, as have at least 3 others... and possibly many more.
    As a new DH diver I had no idea what was happening, very disconcerting to first experience on a night dive!

    The reason I started this thread was to try and tap into the broader experience of this forum... there are plenty on here who have forgotten more than I will ever know about DH diving.

    If you read the earlier posts in this thread you will discover some of these "amateurish design changes" are being proposed after considered discussion by other members who can actually contribute detailed technical knowledge, conduct test dives and help VDH identify the problem and find a robust fix.

    After returning my Kraken to Bryan to fix the premature HP seat failure issue, he also refaced the exhaust valve seat area in a mill.
    In subsequent tests I did not experience the exhaust loop flooding issue again, despite trying every orientation and breathing pattern that had previously caused a major flood. So while I am waiting for others to confirm via their own tests it would seem that seat distortion is the primary cause of the loop flooding issue.

    The wet breathing is another issue.

    As I mentioned earlier, despite contemporary developments like Moldflow analysis injection moulding is still very much a black art. I'm not sure how Bryan organises each Kraken production run but if the cans are produced in small batches then it is quite possible there will be considerable variation if the moulding house has to set up the tool parameters for each run. Different batches of the same resin (probably PC ABS) will also have slightly different characteristics.
    So an early run of cans may be fine, but a particular later batch may all have the distortion and suffer exhaust loop flooding.

    There are considerable differences in wall thickness in the top can moulding ranging from ~6mm to ~2mm around the exhaust spider. The part will cool more rapidly in the thinner wall section and retain heat much longer in the thicker areas leading to sink marks and weld lines where two cooler resin fronts meet each other. These are obvious around the exhaust horn to body intersection and the exhaust spider 'arms'.

    The GE Plastics Design Guide is an excellent overview... a little dated now but covers all the basics:
    http://plasticwright.com/files/8314/0476/4159/GE_plastic_design.pdf

    How to fix this?
    Given the relatively low production numbers it is possible to manually resurface each exhaust face with an end mill or even a small sanding disc piloted to the exhaust arrow hole. It would seem only a small amount is needed to be removed, but this critical area needs to be checked for flatness on each can before shipping.
    For a longer term fix tool mods will probably be required... a copper insert around the exhaust spider or better water channel routing/flow? Need to see the tool design drawings before I can comment further.
     
    lexvil likes this.
  6. SurfLung

    SurfLung Nassau Grouper

    # of Dives: 200 - 499
    Location: Central Minnesota
    95
    99
    18
    Actually, I DID read all of the previous posts... All 9 pages of them. And that's why I felt compelled to offer an opposing viewpoint. I apologize for having offended you guys. Perhaps I could have been gentler in my wording. But that's my opinion and I'm sticking to it.
     
  7. lexvil

    lexvil Loggerhead Turtle

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    1,414
    935
    113
    Your opinion regarding my regulator is wrong, you may want to try a very slight vacuum on the DBE, on mine it leaks or did leak until I lapped it in and switched to the G250 mushroom, unfortunately I did two things at once but I had replaced the original valve with a stock one and the issue persisted and now it may not, as Fibonacci pointed out it may be a simple material issue and slight warpage or a flash sort of thing, my 2014 Kraken didn’t have the issue but it is/was persistent in my 2017 model. The only time I ever had wet breathing was with the original DSV the turned to easily and it partially rotated during decent, the new o-rings solved that. I’m a big fan of the Kraken and DH in general but the exhaust hose flooding really robs one of the pleasure of using it. I also had the creeping IP, Bryan replaced the parts but that didn’t last long, also intermittent so when checking my reg before my last trip the IP shot up to 170, ordered a kit but didn’t get it in time so not I’ll test the flooding issue locally but the lock up is perfect at least.
     
    Fibonacci likes this.
  8. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    537
    442
    63
    @lexvil interesting... my problematic Kraken is also a 2017 model.
    Do you have any pics of the failed HP seat?
     
  9. lexvil

    lexvil Loggerhead Turtle

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    1,414
    935
    113
    97B5B6B0-BD2C-4494-A942-0FE32D9C33E8.jpeg DC79FE20-165C-4B45-9870-3C8574100CB6.jpeg
     
  10. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    537
    442
    63

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