Misc BP/Wing questions

Discussion in 'Buoyancy Compensators (BC's) and Weight Systems' started by Scared Silly, Sep 20, 2006.

  1. Scared Silly

    Scared Silly Regular of the Pub

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    Over the weekend I finished assembling my first set of doubles (AL80 with Highland Band and a SeaElite Manifold). Everything went very smoothly. The only thing that is bothersome is that it seems like the bolts supplied with the bands are 1/2 inch too long. Once I have the BP and wings on the threads stick out about 1/4 inch past the wing nut just far enough that I can feel it poking into my back.

    I did some searching and found that some folks solve this by adding a stop nut so that the backplate does not flex so far back. I am currently trying this but it would seem that you really the BP to sandwich the wing aganst the tanks. Any thoughts suggstions?

    The other item is that I have been looking at different tanks and configurations and the required lift that I will require from a wing. Currently, I have a 55lb wing which from my calculations the most I would need is around 38lbs of lift. So based this I could get away with a 40lb bladder. But given mfg ratings are done a bit different and that if I did really need want the full lift capabilities would it be a bit better to size up a little bit to something in the 45 lb range rather than push it so close?
     
  2. Tamas

    Tamas Loggerhead Turtle

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    If the bolts are too long, you could always cut off the excess with hack saw or wheel. You have to remember that the bolts supplied are the same as the ones for the 8" diam bands and the extra you get is from the 7.25 vs 8 diam
     
  3. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    Where are the ends of the bolts with respect to the tanks? If you placed a straight edge across the tanks, parallel to one band, would the end of the bolt extend past the Diameter of the tanks? It should not. As long as the bolts don't project past the plane of the tanks it would be truely remarkable to be able to "feel" the ends of the bolts. Place your back flat against a door, or a wall, now check how much room there is between your spine and the door. Without rolling into a ball most people cannot get their spine to touch the door.

    You do want the trap the wing between the tanks and the plate. That's what really keeps everything in line. If you are using a lightweight plate a stop nut might help, but should not be required with a SS plate.

    How did you calculate your required lift?



    Tobin
     
  4. Jim Baldwin

    Jim Baldwin Scuba Instructor

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    I agree with Tamas just use a hand grinder or hacksaw and then use some emery cloth or sandpaper to smooth out the rough spots.

    As far as the wing stay with what you have. One of my wings is setup for doubles with a Dive Rite 55 lb wing. It has handled two 120 HP steel tanks and two 80 AL sling tanks with no problem. It's better to have a little more lift and not need it than not have a enough. Remeber that your wing needs to be able to float your tanks full at the surface.

    My two single wing setup both have 40 lbs of lift and easily float a 95, 100 or even a single low pressure 120. I dive in a 3mm suit and use no weight. I use very little air in my wing at depth so I could get by with a smaller wing on these two setups.
     
  5. Scared Silly

    Scared Silly Regular of the Pub

    # of Dives: 500 - 999
    Location: Up a river of excrement in a native american water
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    Just the way you have posted :D.

    Rig Weight
    Dual HP120 full 2 x -11 = -22
    bands/manifold -3
    bp SS -6
    regs -2
    lights -3
    misc (reels, dry suit inflation) -2

    Total -38lbs

    Exposure Suit

    Dry Suit 15
    Gas 18
    Dry suit inflation 2

    Total 35lbs

    This is worst case (i.e. greatest amount of gas) Also with my dry suit in fresh water and minimal clothing 11lbs was needed to sink with minimal exhaling. So I added 4lbs to offset clothing and salt water. The dry suit (DUI 200CX) bouyancy was probably the most surprising as I had never done this test before. I would guess that my 4/3 suit would be similar. I will try it next week.

    I will check the bolt lenght tonight. I would guess that as Tamas noted Highland sends out the same length whether for 7.25" or 8" bands.
     
  6. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    You should be fine in a 40-42 lbs wing.

    Tobin
     
  7. kidspot

    kidspot Scuba Instructor

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    I don't know which bolts Highland mills uses, but the bolts I have are threaded on both ends, so I just take up the "excess" on the other side of the tanks. If these are Hex bolts (with a head on one end) you could also spin a nut all the way to the head so as to take up the excess as well...

    But cutting them off is probably the cleanest solution, just be sure to put a nut on the bolt before cutting so you can unscrew it and smooth out the threads after cutting.

    Aloha, Tim
     
  8. Scared Silly

    Scared Silly Regular of the Pub

    # of Dives: 500 - 999
    Location: Up a river of excrement in a native american water
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    If I place an edge over one band the bolt end is approximately 1/4 inch below the edge. So the bolt does extend past the tanks. If I place my back against a wall I can feel a ball point pen between my spine and the wall. I guess I am truly remarkable :D. My mama always said I was special. I should note that I have not have the rig under water yet. So I am only feeling the bolt ends on dry land.
     
  9. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    I'm having a hard time following your description. If you laid the tanks down on a flat table, diver's side down, would the bolts gouge the table?

    They should not. If they project beyond the plane of the tanks they are too long.


    Tobin
     
  10. Scared Silly

    Scared Silly Regular of the Pub

    # of Dives: 500 - 999
    Location: Up a river of excrement in a native american water
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    No the bolts would not gouge the table, they would clear it by 1/4 inch. So they are not too long - I think I am AB Normal :D
     
  11. GreenDiverDown

    GreenDiverDown Scuba Instructor

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    What plate are you using?
     
  12. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    You should be fine. You might be able to feel a pen between your spine and the wall, but can you do it where the band bolts penetrate the backplate?

    Tobin
     
  13. NWGratefulDiver

    NWGratefulDiver Mental toss flycoon ScubaBoard Supporter

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    This one falls into the "learn from my mistakes" category.

    If you're gonna cut the bolts off, disassemble the unit first. I figured I'd be fine just putting a towel over the wing to catch the sparks from the dremel tool I was using to trim the bolts. Nope ... the (red-hot) cut piece fell onto the backplate, rolled into one of the backplate holes, and did a "China Syndrome" on my wing. I liked that wing too ... before I put two big burn holes in it. Oh well, got to replace it with one of Halcyon's new designs ...

    ... Bob (Grateful Diver)
     
  14. Scared Silly

    Scared Silly Regular of the Pub

    # of Dives: 500 - 999
    Location: Up a river of excrement in a native american water
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    Thanks for all the help. Greatly appreciated

    Tobin, I placed the pen approximately where the wing nuts would be and could more or less feel it. I know that when in the water my back will have a bit of an arch to it.

    Stephan this is with a Zeagle BP.

    Instead of cutting the bolts I think I will just buy some that are 4.5 inches and see how that works. There are several supply houses close by so it will not be too hard to find even in SS.

    Last spring I dove a similar set up (double al80s) while in Chuuk and did not notice the bolt ends. But again I did not pay a huge amount of attention to it because it all felt fine and being a noobie to doubles and all.
     
  15. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    SS,

    If you want low profile, suit freindly wing nut replacements check these out

    http://www.deepseasupply.com/page13.html

    With these you can cut the bolts so only about .400" projects through the plate.

    Regards,


    Tobin
     
  16. GreenDiverDown

    GreenDiverDown Scuba Instructor

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    You won't find "shouldered" bolts like the ones that came with your bands. I looked all over town for some until I realized that Highland takes a standard shouldered bolt and taps them to extend the threaded portion and shorten the shoulder to fit their bands.

    Your best best... if you really want to change the bolts... would be to buy some SS all-thread and make your own. I don't see any advantage to that, though. You already have the right bolts... just assemble your plate and wing, tighten down your wingnuts and then mark your bolts with a permanent marker where you want to cut them. Then take your plate and wing off and cut your bolts. I've done it with a sawzaw... never have figured out what dremel blade will cut through those things.

    But... once you cut them you may have difficulty using a different plate with a shallower center channel.

    Here are some pics...

    Diagram of how to set it up with all-thread:

    [​IMG]

    A Highland bolt cut down next to an all-thread bolt:

    [​IMG]

    Typical length of bolt:

    [​IMG]

    A cut down Highland and one that hasn't been cut:

    [​IMG]

    In the last pic notice the Blue Molly... a nice little trick from FredT.
     
  17. terrasmak

    terrasmak Manta Ray

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    Oh those make life so much easier , i just need to order another set for my STA. If your diving with a Halcyon style pocket on your plate it makes it easier to swap tanks around over normal wingnuts.
     
  18. GreenDiverDown

    GreenDiverDown Scuba Instructor

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    How so? What's wrong with wingnuts? We've been using them for years.

    You don't need to mess with 'em at all if you are just swapping out tanks... no need to separate the plate and STA.

    For assembly and disassembly; don't attach one of the lower grommets if you're using one of those Halcyon pocket things. And... it's easy to get to the top one.
     
  19. cool_hardware52

    cool_hardware52 Equipment Manufacturer

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    Wing nuts are a taller overall profile, are subject to galling (Stainless to stainless) often require the use of at least a flat washer, and can be unpleasant to remove with water softened hands.


    Tobin
     
  20. GreenDiverDown

    GreenDiverDown Scuba Instructor

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    No... seriously... what's wrong with wingnuts?

    Removing them hurts your hands? C'mon. It aint that bad.
     

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