Atomic B1 vs M1 == comfort vs more capability?

[CAPTAIN SINBAD]

Pardon my ignorance but am I correct in thinking that that sentence just means to seal the 1st stage? Or does it mean seal 1st and 2nd? Are 2nd stage regs even something one would seal? Or since they all (apparently) are diaphragm designs, 2nd stages are all already inherently sealed?

They seal the first stage with Chrystolube. I am unaware of any sealing done to the second stage but it is my understanding that for ice conditions, a second stage with metal parts is preferred over plastic parts. Plus they add some kind of a heat sink on the second stage but I have no idea what that is. I hope some of the more experienced regulator technicians could elaborate on that for both of us.

 

[eelnoraa]

The recommendation from Atomic for cold water is 1) use monel piston 2)pack 1st stage with cystolube for sealing 3) added M1 style heatsink to 2nd stage hose fitting.

Monel/brass do conduct heat better than stainless steel, which is better than titanium. For 1st stage, that is why AA is recommending monel piston. For 2nd stage, it is not recommend to be Ti. I highly doubt the M1 heat sink does anything at all, especially the new one. It is just a bigger chunk of metal with "M1" machine on to it. The older headsink at least has fins. For 40-50F water, I don't see the need to do any of these. If you are diving under the ice cap, piston reg may just be the wrong choice overall.

As for the OP, I would persoanlly goes with Z2/3 in Yoke for single tank/vacation. I don't like 2nd stage swivel, I took mine off all my B2s. For single tank, 1st stage turret actually doesn't do much because the LPI will hold the turrect more or less fixed. When you move to tech training, the cost of one additional reg is very minimal compare to the overall cost of tech diving.

 

[Dr. Lecter]

Thermal conductivity of 316 SS is around 13-17, while monel is around 15. Unlike brass, it's used for O2 compatability, not thermal reasons.

[Edit]Just saw the quote from Atomic above...would love to hear from them exactly what the thermal properties of the monel alloy Atomic uses are, to support the claim it really makes a difference in cold water as well as in O2 compatability. Because I'm not really seeing the connection, but they must know their own materials better than my guesswork does.[/Edit]

 

[stuartv]

Probably because some of us love the corrosion resistance of SS, don't care about the extra 8oz of weight much less want to spend an extra $1000 over a Z3 to avoid it, and think the brass valve tube used in the M1 and Z2/3 versions isn't all that great compared to a Ti valve tube. The B2 is basically a Z3 first stage with a more corrosion resistant second stage valve tube.

I noticed that the service interval is the same for both. So, are you saying that the Z2/3 valve tube has to be replaced more often than the one in the ST1 or B2, because they are more corrosion resistant? How much does a replacement valve tube cost, anyway?

 

[hedgehog47]

I have a b2 and a ST1, I use the b2 primary. I put a 90 degree fitting on there and a miflex hose. Did not care for the swivel.

 

[Dr. Lecter]

I noticed that the service interval is the same for both. So, are you saying that the Z2/3 valve tube has to be replaced more often than the one in the ST1 or B2, because they are more corrosion resistant? How much does a replacement valve tube cost, anyway?

Neither one is a consumable part; with proper care, theoretically neither one ever needs replacing and should outlast the diver. In reality, there's a reason chromed brass isn't the top of the line material for reg bodies - or valve tubes.

 

[BoltSnap]

If you are going to upgrade the Z2/3 with all the features the B2 has, you might as well just buy the B2 and you will have Titanium valve body. All Atomic regulators perform exactly the same u/w when tuned to factory specs. I have gone 5 years without any service to my B2 (sealed first stage) with no issues (I bought it as a B1 but upgraded it to a B2 years later).

If you aren't going tech or diving very cold water, there is probably no reason to buy the M1 now. I'd go for the B2 (sealed first stage option) or the ST1 (more resistance to corrosion and better reliability).

Note that when you go tech, you will have several sets of regulators

 

[bahula03]

One *small* thing that I haven't seen mentioned; Whichever one you settle on, get the wider M1 exhaust diffuser installed.

Also, I'd echo what others have said about the swivel hose...it's not a reason to buy one reg over another, and in use it's a negligible difference in comfort.

 

[hedgehog47]

I have an ST1 and a b2 and on the b2 I took the entire swivel assembly off and instead put a right angle adapter on with a miflex hose routed under my arm. much better.