Vintage Double Hose

Yo, Connoisseurs of Conshelfs, I see the old black neoprene diagrams, the semi clear natural silicone diaphragms, the grey silicone diaphragms and now I think they are the black silicone. Forget the neoprene jobs, between the grey and the black, is there a functional difference?

Hey, I am trying to build a kick azz Conshelf here, what elese can I say

Nem

Nemrod wrote:Yo, Connoisseurs of Conshelfs, I see the old black neoprene diagrams, the semi clear natural silicone diaphragms, the grey silicone diaphragms and now I think they are the black silicone. Forget the neoprene jobs, between the grey and the black, is there a functional difference?

Hey, I am trying to build a kick azz Conshelf here, what elese can I say

Nem

Hi Nemrod... building a "kick azz" Conshelf should be pretty routine if you get the right components. I have all the different diaphragms you mentioned, but I never got around to directly comparing them on the same reg, mainly because whichever one that I picked up first seemed to work just fine anyway. However, I'll bet that there is actually some slight difference when measured on the test bench.

If I were working on my own Conshelf again to use myself, I would go through all the diaphragms you mention, but I have enjoyed my MR-12 III so much that I just stick with it.

The newest available from AquaLung seems to be the black one with a plastic disc. It seems very flexible, but I was a little put off by the plastic disc, so haven't actually tried one. Ha, it might even work the best. Wanting to keep mine as original as possible, I used a diaphragm with the metal plate... but admittedly just picked a gray one without testing the others.

If you don't have the full selection available, tell me what you lack to test them all, and I will be glad to help you out with some loaners for the experiment. (I would do it, but since this was your idea, you deserve the honors for test results)

These are not too shabby in my opinion

Conshelf Diaphragms

Well, you talked me into it. VDH diaphragms on order.

Nem

Pretty much the only single hose regs I own are Conshelfs. I've never noticed any particular difference in the different types of 2nd stage diaphragms, except for an old one I got on a Conshelf 2nd I got with an old piston reg(it was hardened and crackly, likely due to how or where it was stored).

Thanks, when I get the new diaphragms maybe I will just run them on my Magnehelic.

James

I've used all 4, being the old rubber, gray silicone, clear silicone, and fancy new thinner black one. I've had the best luck tuning the reg to breathe light with the thin new one. I would imagine it offers less force against inhalation effort, and it is slightly more flexible. Byan sells the best ones. Skip the rubber ones, they are usually crispy.

Speaking of Conshelfs, in the past, I would run the the two second stage hoses from a three way or use a three way to give me a LP outlet for the BC hose. The clocking is just not right, really, with the Conshelf first stage--what were they thinking? Sometimes I would use a right angle swivel for the BC hose. On my latest Conshelf that is exactly what I did. I did not want the chrome wearing from the swivel so I placed a thin Mylar washer under the swivel to act as a rub pad.

Of course, this oddity is not something I just recognized and of course, USD did in the end add that fourth LP port.

Nem