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'Pimp my dive !' Suggestions for modernizing my SP Mk 5 / 109 ?

Discussion in 'Vintage Diving & Equipment' started by scubafanatic, Jan 12, 2014.

  1. elan

    elan Contributor

    # of Dives: 200 - 499
    Location: Toronto, Ontario, Canada
    They had them in the store a year ago, I purchased a few last ones for my regs. I donno if they had other production runs.
  2. scubafanatic

    scubafanatic Contributor

    Do you 'see' Scubapro or an after market entity producing a batch of these exhaust T's/purge covers (of silicone) ? If, to date, noone has done this to date, what do you see happening to get the ball rolling after this many years ? Who/what sends the Bat Signal to Scubapro (or whoever) ? Scubapro more probably has a vested interest in seeing these old regs scrapped, so what possible third party could be motivated to intervene here ?

    ---------- Post added January 20th, 2014 at 05:43 PM ----------

    OK, sounds like I need to put him on my short list of contacts !
  3. Nemrod

    Nemrod Contributor

    I do not see anything, I do not follow your question or is it a statement? Only a few years ago when I went searching for new hoses for my Mistral, there were NO parts available for any double hose regulator. Upon contacting a mold fabricator and a company making hoses for SCABA equipment, the owner told me, "you are the third person in the last year who has contacted me" and I asked him, like, who, what and where I got put on to vss and then along came vdh. Where there is interest, if it is sufficient, there could be parts.

    It is not rocket science to make molds and cast parts, I was starting down the road when I discovered there were already interested parties and preferring to save my thousands of dollars for other things than making molds, I decided to support the businesses who were already making progress and had made hard cash investments.

    The point is, who knows what can happen if there is sufficient interest. And, I do not mean vdh necessarily, their plate is full as it is, nothing keeps another party form making the investment. Heck, maybe when I retire, who knows. I got a lot of projects, two airplanes to finish, a Jeep to finish (that is breaking my bank) and a host of other major undertakings and so little time and money to do everything.

    As I understand, a few years ago, a group had a run of covers and tees made, I assume with SP. I bought several at that time. Maybe ask them what they see or saw.

  4. scubafanatic

    scubafanatic Contributor

    Hi N,
    To clarify, it was a question, wondering when (again) would all the necessary conditions arise to have SP or someone do another run of those parts ? As you say, I'd have to piggyback off an interested group as it's financially impractical for the average individual to fund the molds. Wonder what kind of order quantities would be needed as well as pricing ?
  5. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    The group buy we had a few years ago was put forth first as a question to find out how much interest there was. We reasoned that if there was enough interest, we could find someone who would manufacture the exhaust tees and diaphragm covers. Enough people spoke up in favor so the search was on to find a vendor. We had a few bids but in the meantime someone contacted me and gave me a reasonable price per unit for genuine ScubaPro parts. If I'm not mistaken, we had an order for 75 diaphragm covers and 50 exhaust tees. It probably turned a nice profit for the seller. I am not privy to the details between the person who acquired the parts and ScubaPro.
    rhwestfall likes this.
  6. rhwestfall

    rhwestfall Woof! ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: "La Grande Ile"
    Yep, that's how it went down..... It was a bulk order of parts from SP by a very helpful SP Dealer, and one individual here coordinated the parting out of the order and distribution.
  7. halocline

    halocline Contributor

    Scubafanatic, in response to a few of your concerns, although others have also commented:

    1. The yoke you have with the 5 port 1st stage is perfectly fine for HP tanks.

    2. If you want to pack the chamber with grease, it works fine without a boot. Those little holes contain the grease really well, it is surprising.

    3. There's also no problem with getting salt water out of the chamber as long as you soak the reg after salt water use. It's likely not as efficient as much larger environmental chamber holes would be, but it still works fine. I have several of these 1st stages, I've never had any sort of problem with corrosion in the chamber, whether it's packed or not. I would not bother packing the ambient chamber unless your intention is to use the reg in extremely cold water.

    4. The HP use of these first stages is fine, they can 'handle' pressure, there's really very little difference between them and the later balanced piston firsts. There is a caveat to this; the later model first stages, starting with the MK15, use a bushing system to lower the clearance gap around the HP piston o-ring. This means less extrusion of that o-ring, which practically speaking means less IP rise at very high tank pressures. IME the best o-rings to use on the HP piston area are duro 90, and the SP rebuild kits come with duro 85 I believe. You can feel the difference in stiffness.

    So, if you're looking for IP variance within a couple of PSI from 3500 to 500 PSI, the MK15/20/25 is your best bet. Those of us who like the older regs better don't care that the IP is 7 PSI or so higher at pressures above 3000.

    5. It's pretty likely that your 5 port MK5 already has a steel turret bolt. If not you can buy one but unless there's some visible stress on the threads of the brass one or some evidence of abuse (you can check with a jeweler's loupe) I would not bother replacing it. I bought several of the steel turret bolts when we did the run because I wanted to support the project. I sent one to Bryan and the rest are sitting in my cabinet. The problem with the brass bolts was simply bad technicians cranking down on them. Not that I do this every day, but I have taken apart many MK5s over the years and have found exactly one questionable looking turret bolt. It was in there really tight.

    Certainly there's nothing wrong with changing it if it makes you feel better. Someday I'll remember to do that on the one-or-two of my MK5s that came with a brass bolt.

    6. Don't worry about the rubber parts on the 109, they'll be around for a good long time. This is likely the most successful 2nd stage ever produced, when you consider performance, durability, longevity of production, and influence on other 2nd stages, including most of what SP has produced since.

    7. One thread that I have found very helpful was the one about the various 2nd stage lever versions. My experience is that the newer lever version, with the curved feet, is an improvement over the older models. It seems to be a bit of a crapshoot as to how an older lever works with the s-wing poppet. Sometimes you put one in and it's great from the start, sometimes the lever height is not correct and you need to de-tune the reg badly to stop a free flow, sometimes it just doesn't have a nice smooth action. I've occasionally touched up the square hole in the air barrel with a little file and that's helped. But in all cases I seem to get the best tunes on these regs with that curved foot lever.

    8. Don't worry about the piston in the 1st stage, I don't know if I've ever seen one that didn't lock up with no creep perfectly. Maybe I just can't remember, but I've seen plenty of MK10 and MK20 pistons creep. Even if yours has a little ding or scratch on the edge causing some creep, it's not hard to polish out with some micromesh or a small abrasive cone. This ain't rocket science, just patient and careful work. In all cases when I get one of these regs (MK5 or 10) I use a bit of micromesh on the piston shaft to break up any glazing in the area of the HP piston. It seems to lower the friction in that area and hold lube a little better.

    9. The biggest challenge is finding a technician who's not a knucklehead with slightly older gear and can work on these regs well. There's a SB member named 'axxel' or something like that who seems to have a good through knowledge, at least his posts are very accurate. I think he's a working tech. Most of us who frequent this board do our own work, but not as a business.

    With regards to the MK5/MK10 rivalry, my opinion is that the MK5 is an overall better design. I'm fairly sure the MK10 diameter was a result of machining limitations, maybe financial, because SP wanted to bore the ambient chamber and HP piston journal out of one continuous billet in order to ensure accurate alignment. The others have threads connecting the two chambers, meaning that it's possible with thread tolerances to have a slight off-axis alignment between them. SP probably felt that they could lower the gap between the piston shaft and journal in this way, because the exact alignment ensured that the piston would not be pushed sideways by a less-than-perfectly-aligned ambient chamber. I'm not sure if that makes sense to you.

    Anyhow, the smaller piston diameter really has a trade-off, and true to form, I find my MK10s are more likely to creep after a year of two of use and have more IP swing between full and empty tanks than do my MK5s. So I can't agree with Wookie about the MK10 being 'the best' of the SP 1sts. That award would rightly go to either the MK5 or the MK25, and time will tell. Both have had really long successful runs and profound influence on other regulator designs. Both can easily provide years of service without rebuilds or any indications of problems.

    There's nothing wrong with MK10s, in fact that's what I use for my doubles/cave rig, because I have them in DIN. Mine are currently packed and with SPEC boots, but when I rebuild them in a few years I'll probably dispense with the packing. They never see any water colder than high 60s.

    That's probably the single longest post I've ever done....
    Umuntu, John C. Ratliff, couv and 2 others like this.
  8. Zung

    Zung Contributor

    # of Dives: 500 - 999
    Location: Geneva, Switzerland
    I've got a MK5 with a not too old DIN wheel; I just counted the threads, and there're 7 of them, so it must a 300 bar (4350psi).
  9. agilis

    agilis Cat Lives Matter

    # of Dives: I just don't log dives
    Location: N.J.
    My MK5 Din connector also has 7 threads. The one Thermo and two XS valves I have on my three steel tanks all state a max pressure of 3442, though the dive shop I use routinely fills them to 3600+.

    When the MK5 DIN fittings are fully screwed into the XS valves there are two threads still visible. These tanks are in my basement. The Thermo valve is on a tank in my detached garage and it's snowing like crazy at the moment.

    I must admit I know almost nothing about the different DIN configurations. If PADI does not offer a DIN certification I'll have to do some reading.
  10. Nemrod

    Nemrod Contributor

    Well, my best 109 set is gone walkabout (it has gone for a visit with a friend, they want to commune) and I do have parts. But, as a basic hoarder, if there was ever to be another order for 109 rubber goods again, I would go in. I have a sad set staring at me on my shop table but I am loath to break into my stash. Kind of like since I found I could not buy 22 ammo anymore now all I do is buy it and never shoot it. Of course, the enemy (skunk, armadillo) insurgents about my place have gone on a spree as a result. There will be, as we say from down South, a reckoning.

    John C. Ratliff and agilis like this.

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