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MK5 Question

Discussion in 'Regulators' started by Open Ocean Diver, Aug 29, 2020.

  1. Open Ocean Diver

    Open Ocean Diver ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Lauderdale-by-the-Sea
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    Hi all, just received a beautiful NOS MK5. Since the spec cap doesn’t have provisions for a boot what type of grease would you use to keep it environmentally sealed without too much leakage?

    Seems to me with the small holes rinsing thoroughly would be tough without the grease.

    Thanks,
     
  2. Angelo Farina

    Angelo Farina Contributor

    # of Dives: 1,000 - 2,499
    Location: Parma, ITALY
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    The chamber was designed to be packed with silicon grease.
    SPEC stands for Silicon Protected Environmental Chamber.
    Nowadays silicon grease seems to have been superseded by other types of grease, such as Christolube.
    But I still pack my four MK5 SPEC with high viscosity silicon grease, which is also much cheaper...
     
    Open Ocean Diver, Kupu and axxel57 like this.
  3. herman

    herman Instructor, Scuba

    # of Dives: 500 - 999
    Location: Raleigh,North Carolina
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    DOW 111 Unless you are using high O2 levels (+40%) there is no need to use anything else.It much less expensive and more stable than any of the fancy modern lubes.
     
  4. Open Ocean Diver

    Open Ocean Diver ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Lauderdale-by-the-Sea
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    Thank you ... I have some Christo-lube but figured it would separate and just leak out.
     
  5. halocline

    halocline Contributor

    9,054
    3,494
    If you have the later MK5 with the really small ambient chamber holes, the modern PTFE (christolube, tribolube) grease will work fine; I've used it packing MK5s before. The silicone grease is thicker and very likely more durable.
     
    Open Ocean Diver likes this.
  6. Kupu

    Kupu Polliwog ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: USA
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    Just for fun. MK5 SPEC with small ambient chamber holes at top left, MK5 with environmental kit top right, and version of MK5 without SPEC on bottom right.
    Bottom left is MK10 SPEC with small ambient chamber holes rather than boot groove.
    mk540.jpg
     
  7. agilis

    agilis Cat Lives Matter

    # of Dives: I just don't log dives
    Location: N.J.
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    Why are you packing your regulator with grease of any kind? Will you be diving in very cold water, down near freezing? If not, you don't need any of that messy packing. It's counterproductive. I use Mk 5 and Mk 10 first stages almost exclusively. I've not used any kind of packing grease, Christolube or Crisco, for the past 40 years. If you're diving in temperate or warm water you don't need anything, in my opinion. These regulators work beautifully just as they are. I use a Mk 10 for most dives when on holiday in the tropics. Other than cleaning and checking intermediate pressure, etc., I have not taken it apart for three years. I will soon, only to clean and replace o rings. My advice is to avoid squirting gunk into your regulator unless you plan to do some very cold water diving.
     
    Open Ocean Diver likes this.
  8. Open Ocean Diver

    Open Ocean Diver ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Lauderdale-by-the-Sea
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    I just realized my MK10 does have the small ambient chamber holes, not as noticeable as the MK5. Thanks for the pics.

    My Mk5 looks like yours, top left but with a wing screw.
     
  9. Open Ocean Diver

    Open Ocean Diver ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Lauderdale-by-the-Sea
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    I dive in warm waters, will start doing some shore diving but really the only reason is because the ambient chamber holes were so small I thought it would be difficult to rinse out.
     
  10. Angelo Farina

    Angelo Farina Contributor

    # of Dives: 1,000 - 2,499
    Location: Parma, ITALY
    1,877
    2,931
    I always packed my MK5-SPEC (Top-Left in the picture above) using (inexpensive) silicon grease. This allows to increase the time between rebuilds to 5 years.
    I also have two older MK5 without Spec (Bottom-Right), and I noticed that they need much more frequent servicing, usually 2 years. If not serviced frequently, the large O-ring of the piston starts to leak slightly.
     
    Open Ocean Diver and rsingler like this.

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