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Post by SeaRat on Jul 17, 2017 13:58:05 GMT -8
Hello all!
After reading this thread I went to the garage and pulled out an MR-12, Titan II that looks like JB's second picture, and is serial number 00766. My question is: when were these manufactured? Are they better in some way than other single hose regulators of the same era? During the 70's and 80's I dove with my USD Calypso and it worked well. The answer is, "Yes." The MR-12 force U.S. Divers Company to redesign their Calypso/Conshelf second stages, producing the third and fourth generation of those USD second stages with enlarged exhausts. The MR-12 was the first single hose regulator to be approved by the U.S. Navy's Experimental Diving Unit. This was due to its exhalation performace at depth. This did not keep the U. S. Air Force from buying first and second generation Calypsos for Pararescue, but we had a different approval process. John
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Post by crabbyjim on Jul 17, 2017 15:33:14 GMT -8
I cleaned up the outside of mt MR-12 II then disassembled the second stage. The insides were clean. The lp diaphragm is a rubberized material, similar to one of my Voit Trieste diaphragms. Exhalation is easy but inhaling is a bit harder. JB, Phil, John, what do I do after pool testing?
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Post by nikeajax on Jul 17, 2017 16:21:09 GMT -8
What I did was use John's method for HW-diaphragms. Goop it up in silicone grease and let it sit for a week, then massage the heck out of it, like you're cleaning a bad stain out of a shirt: you can't damage it, be mean! If you can find a diaphragm for a Mares Abyss that will work too. The above method worked really well after sitting for a long, long time, but it's as nice as the Mares when compared side-by-side.
What's the IP set at?
JB
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Post by crabbyjim on Jul 17, 2017 17:58:21 GMT -8
No gauge, no clue.
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Post by vance on Jul 17, 2017 19:01:32 GMT -8
The grease trick will work. It may not get to where you want to go, however. What diameter is the diaphragm? Is it a 2.75" like the Mares?
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Post by crabbyjim on Jul 17, 2017 19:31:49 GMT -8
The od of the ring clamp is 2.75 so I guess it's smaller. I have already reassembled it and don't want to take t apart again tonight. I'll check tomorrow afternoon.
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Post by vance on Jul 17, 2017 20:44:25 GMT -8
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Post by SeaRat on Jul 17, 2017 22:28:21 GMT -8
Crabby Jim, No, do not buy this diaphragm for the MR-12. It has a diameter of 2 1/2 inches, and cannot be used on the MR-12. The MR-12 second stages have an outside diameter of 2 3/4 inches (actually 7 cm), just as you measured. The OD of the diaphragm is the same as the OD for the cover, and the ring is fairly narrow and so does not add much to it. They also have a different sealing system than other regulators, in that they have a rubber bead on the outside of the diaphragm, rather than a raised area on the outside. Treating it like Jaybird discussed, by rubbing in SILICONE grease, and letting it sit, will improve these diaphragms. And, they are pretty much indestructible. They do not get as stiff as the Healthways neoprene-impregnated fabric diaphragms, but the silicone cannot hurt and will add a bit of flexibility. The fabric diaphragm for the MR-12s is the first generation, and better breathing results if you replace it with the newer diaphragms that are of silicone that Mares produced for later models of the MR-12. BUT, the fabric is still a very good diaphragm, and is not like the Trieste II diaphragm, which measures 8 cm (3 3/16 inches), and has a permanent "set" to it that causes harder breathing. I just measured all these diaphragms, as I have some spares here. John
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Post by crabbyjim on Jul 18, 2017 5:32:23 GMT -8
Thanks to all of you! After I return from the Aquarium this afternoon I will massage silicone into the diaphragm until my fingerprints disappear. I may take one of my Trieste's apart because John has piqued my curiosity about the diaphragms.
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Post by nikeajax on Jul 18, 2017 7:45:15 GMT -8
Jim, it works best if you use a goodly amount, not just a dab, and let it sit: I put mine in a plastic bag. You can get good results if you massage every couple of days and re-goop (lather, rinse, repeat...), then store in the plastic bag.
WARNING: Wipe off all grease before trying to use the diaphragm! Jim Steele was telling me that they can walk out of their seating!
JB
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Post by vance on Jul 18, 2017 8:28:20 GMT -8
Jim, it works best if you use a goodly amount, not just a dab, and let it sit: I put mine in a plastic bag. You can get good results if you massage every couple of days and re-goop (lather, rinse, repeat...), then store in the plastic bag. WARNING: Wipe off all grease before trying to use the diaphragm! Jim Steele was telling me that they can walk out of their seating! JB Not only wipe the grease off, but clean the seating rim of the diaphragm and the can/cover with soapy water to remove all the grease. The diaphragm can get sucked out with a vigorous intake of breath. I've had it happen! So John, are the silicone diaphragms available for this?
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Post by SeaRat on Jul 18, 2017 8:38:43 GMT -8
So John, are the silicone diaphragms available for this? Yes, there are. John
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Post by nikeajax on Jul 18, 2017 9:23:51 GMT -8
Phil, for the older models Titan-II, I think it's the Mares Abyss: Steele's doesn't have them! He may have the newer kind though...
JB
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Post by nikeajax on Jul 18, 2017 10:44:33 GMT -8
Jim, please e-mail me: we can set up a time to talk; I'll walk you through... EVERYTHING! JB
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Post by crabbyjim on Jul 18, 2017 19:26:35 GMT -8
So John, are the silicone diaphragms available for this? Yes, there are. John The suspense is too much. Where are silicone diaphragms available?
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