R4 regs

[SeaRat]

Mossback,

No, I did not manufacture any diaphragms for the Dacor R4. That reg, with its duel diaphragm concept, is rather difficult to manufacture for, and I would advise against it. There must be someone out there with a set of diaphragms for the R4 that they would sell you. I say that because the R4 diaphragms were some of the best around in responsiveness, made very thin with a double "S" curve that really allowed them to sense the lack of pressure.

Concerning how I did it for the Trieste II, I used a rubberized nylon fabric, and glued the plate onto the fabric. I then prepared the regulator by putting silicone grease on both metal edges, then laying down a layer of ShoeGoo. I then laid down the diaphragm fabric (not cut to size yet) on top of the still wet ShoeGoo. With the bottom box also layered in silicone grease, I set that on top of the diaphragm, and put a weight on top of the whole affair (keeping it vertical, with the bottom box on top). I let it sit that way for about three days, for everything to dry, then took it apart carefully, and trimmed off the excess material. I then let it sit out for a week to off-gas, and finally put the whole thing together.

This could work with the R4, but it would be a bit harder because of the plate and the exhaust valve. You would probably have to separate the top and bottom part of the plate (if that's possible), then glue them together again. I haven't seen one in years, and so this description is coming from memory of about 25 years ago. As I said, for this regulator, this probably is not a good option, and it would be much better to get some new ones off the internet somewhere.

John

[SeaRat]

Mossback,

Actually, if this is an R-4, there is an adjustment that can be made. There is a slot screw right straight down on the HP diaphragm which can be turned clockwise (to increase interstage pressure) and counterclockwise (to decrease interstage pressure). The interstage pressure can be read by removing the second stage valve body, and screwing in a pressure guage (as my memory serves me). You may also be able to remove the Valve Seat Carrier (which holds the valve seat) and screw in a pressure guage, but as I recall it was the former way, not the latter way, that I did it.

The "Dial-a-breath" was for people who did not like easy breathing

John

[SeaRat]

Mossback,

For the diaphragms for the Trieste II, I used the same glue that I made the gasket on the side with, the ShoeGoo (that's what the bead on the surfaces was meant to do, provide the gasket on the diaphragm, both under and over the diaphragm and incorporated in the diaphragm as it would be on a regular one). It seemed to work, but you have to watch it to ensure that the metal "sticks" well. For the R4, you may have a different possibility. If the diaphragm plates are sandwiched together (two plates, one over and one under the rubber), you can remove the pop rivet and perhaps rivet it together for the primary diaphragm, with just a dab of glue to make a waterproof seal. I seem to remember that this may be the construction of the R4 diaphragm, but again that was a long time ago, so I may be wrong here.

For the material, I have a better source, and can send you some of the material if you'll PM me about it. I'll discuss it later today here, as I'm at work and have the links on my home computer.

!!!DANGER!!! DO NOT USE WITHOUT A BACKUP REGULATOR OR OCTOPUS[/I]

I hope that you realize, as I hope everyone else realizes, that this is experimental, and not done to manufacturer's specs. Therefore, there is a certain amount of risk in making your own diaphragms for a regulator. When diving a regulator with these kinds of modifications, you need to have a backup octopus or safe second stage. When I dive my Trieste II, I have an MR-12 second stage octopus with it, or I dive my twins with a backup regulator.

A couple of points on the setting of the interstage pressure. You probably do not need to know the interstage pressure to do it, as it will vary depending upon the tank pressure, I think. As I recall, this is an unbalanced diaphragm first stage, and so the interstage pressuer is best set at about 500 psi tank pressure to a point where it leaks a bit, and then back it off a quarter or half a turn on that little slotted screw. That way, it will be correct when you breath the tank down to 500 psi or so. If it is set at high tank pressure (2250 psi), then it will leak at the low pressure, as the interstage pressure increases as the tank pressure drops. Also, don't try the second way I mentioned above (removing the seat carrier), as that may damage the seat if you scew in a pressure guage.

John

[Scotty]

Mossback, I had hoped to post news that I had several good used R4 diaphragms socked away that I would have gladly sent to you just to be rid of them, but alas, I pitched my remaining Dacor double-hose parts last winter. I couldn't find anyone who wanted them, mainly because Dacor's vintage regs usually don't rate very high on the "collectability" list, the C3 notwithstanding. I own several versions of the R4 "Dial-A-Death," including a new-in-the-box model from 1974 w/o the adjustment spindle. All are incredibly bad breathers that work better as wall-mounted conversation pieces rather than actual in-service vintage regs (said conversations usually center around the poor design of Dacor's pre-Pacer regulators in general). I will, however, keep my eye out for any that might have escaped me, as I am packing up to pull stakes and move from Pennsyltucky to Florida next week. If I find any R4 diaphragms left that I missed, you'll be their new owner. Oh - one more thing: I wouldn't advise manufacturing your own diaphragms for this unit, or any other reg for that matter. Even if you are successful in coming up with something that "works," you'll never match the durability and sensitivity of OEM. Besides, breathing from an R4 is enough work without the added headache of substituting homemade parts. Be careful. -Scotty