Not "vintage" in age but still a double hose, the Nemrod Silver Snark III from the 1990s, does anyone have any experience with these?
I'm picking one up for a reasonable price to try it out. It is circa 1992-ish. Yoke says 4000psi and has an LP port.
How do these breathe compared to say a rebuilt Aqua Lung like a DAAM or a Mistral rebuild?
Are parts available for these late model Nemrods?
OldBubbles,
First, that is not a LP (low pressure) port, but rather a gauge port for a submersible pressure gauge. It is HP (high pressure) air coming out of that port, and if you put a LP line for an octopus or worse yet, an inflator, it will overpressure and burst the hose.
I have a Nemrod Snark III that I've been using for years. It is not the Snark III Silver, but a generation before that one. The Snark III internals have not changed to my knowledge through these generations. The differences include the addition of a high Pressure port, the mouthpiece, and the looks of the case.
I have identified two major design problems that affect the performance of the Snark III:
1. The mouthpieces are undersized, resulting in restrictions to breathing, especially at high demand.
2. The Venturi (yes, it has one) is improperly aimed. The air designed to go down the intake horn actually is aimed upwards, and impacts the diaphragm, pushing it up, inhibiting the flow.
I have modified my Snark III in two ways to address both these problems.
A. I removed the mouthpiece, and replaced it initially with a Hope-Page mouthpiece (a vintage mouthpiece available in the 1950s for the Healthways Scuba regulator). Then I went back to the Nemrod mouthpiece, removing the non-return valves, which helped. Then Vintage Frank from Germany gave me a English mouthpiece (Norgille?) which is now on the Snark III hoses. This works very well, as does switching totally to the U.S. Divers/Voit hose/mouthpiece system.
B. I have placed a makeshift "baffle dome" within the regulator, made of plastic from a one-gallon plastic milk jug. This does not impinge on the lever system, but does deflect that air stream toward the intake horn while blocking that same air stream from hitting the diaphragm.
With these two modifications, my Snark III breaths the equivalent of a USD Mistral at 500 psig or lower tank pressure. This is because of its upstream design, much like the Mistral in it's second stage. The Snark III regulator becomes a very easy breathing regulator, and because of its double lever system, cracking effort is very low. Note, it's said to be a three-stage regulator, but the "third stage" is simply an overpressure relief valve (OPRV), which is necessary because of the upstream second stage. Without it, a first stage malfunction could explode the regulator.
There is a group out of Turkey that has put together a Snark IV adapter/first stage (see photos below) which will convert a Snark III Silver into a thoroughly modern regulator with both LP and HP ports. I cannot remember the people involved, but did save these photos of what they have crafted.
SeaRat
PS, I'll see about getting photos a bit later (on a different computer).
PS1, Found it:
Finally! Today I was able to assemble the prototype of what promises to be the only news for Nemrod bitrachea regulators that appeared in the last half century. A modified Nemrod Snark III or V-2 with a compensated first stage and equipped with 4 LP exits and two HP outputs to connect manometers, octopus consoles, inflators, etc. Such an element cannot be improvised, and this is the fruit of the long and close collaboration with that precision mechanical genius that is Ernesto Critzmann. Constantly flying pieces from Buenos Aires to Barcelona and vice versa, discussions and opinions until late hours of the morning, laughter and above all, illusion. But we finally have a mounted, calibrated, tested and fully operational prototype. Few things will have to polish. Naturally, neither Ernesto nor I are one of those who make things easy. We only get to work if the ′′ experts ′′ tell us it's impossible to do so. It's not the first time, nor will it be the last. The Snark III Silver (the most modern ones) will not be able to be modified at the moment. It must be impossible... We'll see...
Enrique Dauner
PS2, note that these outlets will be with metric threads, not U.S. Standard. That means that either an adapter or metric hoses/octopus need to be used with this modification.