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Discussion of diving methods and equipment available prior to the development of BCDs beyond the horse collar. This forum is dedicated to the pre-1970 diving.
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SurfLung
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Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
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VCR2 and VCR5 vs. Mistral

Fri Jun 24, 2016 5:38 pm

VCR2 and VCR5 vs. Mistral
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- I thought I'd share a little tidbit of knowledge I learned in the process of restoring a couple of VCR2s (Voit 50 Fathom Compensated Regulator). The VCR2 and VCR5 are "Downstream" single stages. Meaning, the valve opens WITH the airflow and is held shut by spring pressure. The VCR5s have blue plastic cans and the VCR2s have brass cans finished in either metallic blue paint or shiney chrome. Theses regulators actually breathe easiest at full tank pressure and get harder to breathe as the tank pressure goes down.
- The Mistral, on the other hand, is an "Upstream" single stage. Meaning, the valve opens AGAINST the airflow and is held shut by tank pressure. These Mistral regulators breathe hardest at full tank pressure and easier as the tank pressure goes down.
- Greg Barlow was a big help in telling me how to Set up the "VCR" downstream regulators for easiest breathing. Mine have the large Venturi port pointing directly into the inhale hose and the super sensitive VDH silicone diaphragms. And, I can induce free flow at full tank pressure by simply kissing the mouthpiece! I have a Phoenix HPR that will do that but nothing else. So, my opinion is very high of how easy breathing the Voit 50 Fathom VCR2 and VCR5 regs are.
- However, Greg once told me that he breathes his tanks down to 700 with the VCR2 and then switches to a Mistral to breathe the rest of the way down to empty... Using the easiest breathing range of downstream and then upstream regs. Which made me wonder how bad could the VCR2 get if I breathed it down to empty?
- Well, I tried it a couple of times while picking up sticks under the dock. I think the difficulty starts to feel like any other reg feels when it's time to pull your reserve. I wasn't exerting myself very much so I wasn't putting much demand on it and breathed right down to empty. I don't feel it gets bad enough to have to quit using a VCR2 at 700 psi. Since that test, I have dived my VCR2s right down to the reserve level and pulled the lever to finish a dive with nearly 0 psi. I breathed these regulators down to reserve level and beyond at least two times at the Sea Hunt Forever Show in Silver Springs, Florida. I love 'em. :)
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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eskimo3883
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Joined: Mon Aug 14, 2006 5:15 pm

Re: VCR2 and VCR5 vs. Mistral

Mon Sep 05, 2016 7:00 pm

Been off the site for a while for no particular reason and only just saw the pics of your Voit. Is that a Douchbag chrome job?
“A skin diver is a fellow who pulls on a pair of fancy swimming trunks, some rubber fins, a diving mask and canvas gloves, then fills his lungs with air and noses down into the ocean looking for two fisted trouble.”

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SurfLung
Master Diver
Posts: 1763
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: VCR2 and VCR5 vs. Mistral

Wed Sep 07, 2016 9:12 am

- That's actually the original chrome. There still are some beauties to be had out there. Last year, I bought a DA Aqua-Master with Like-New chrome and used it to build my Hot DAAM Royal Master.
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- This is BEFORE... Chrome is like new.
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- This is AFTER... With Cyclone Balanced 1st Stage, HPR 2nd (the Hot DAAM treatment), and New Label.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

User avatar
SurfLung
Master Diver
Posts: 1763
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: VCR2 and VCR5 vs. Mistral

Wed Sep 21, 2016 11:43 am

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VCR2 Performance w/Reserve Valve
- This past month, I had a couple of opportunities to dive my 50 Fathom VCR2 regs with single tanks and J-Valves. Here's what I experienced:
- REMEMBER: The downstream valve of a 50 fathom makes it easiest to breathe at full tank pressure and the breathing resistance should increase as the tank pressure goes down. This is the opposite performance of the Mistral... Which has an upstream valve, breathes hardest at full tank pressure and gets easier as the pressure goes down.
- My 50 Fathom VCR2 regs (both) will present SOME increasing breathing resistance as the tank pressure goes down, but I don't think it becomes noticeable to me until the pressure is in the 300-700 psi range. And, I only think I'm noticing it because I'm looking for it. I usually try to relax and not get over exerted when diving... So I'm not putting a lot of demand on these regs. I have breathed them down to zero psi on several occasions. But on many of these occasions, I may have mistook the low pressure breathing characteristics for running out of air and pulled the reserve valve before I was really out of air. These times I was using my twin tanks.
- Anyway, I dove my 50 fathoms down to zero psi with single tanks this time. And, I actually sucked hard and fast to be sure the tank was not giving me any more air. The first dive I knew I was getting low and was expecting the breathing effort to increase. But the second dive I was using a partially filled tank and was totally surprised when it ran out of air. In both cases, I pulled the J-rod and felt the refreshing ability to breathe again. And these 50 fathom VCR2s seemed to be giving me plenty of air even in the reserve pressures of 300 psi and below.
- I don't know if this info is of help to anyone. But, I feel like the whole idea that 50 Fathom VCR2s are hard to breathe at low tank pressures is maybe a bit exaggerated. Its not necessarily a BIG negative... Just a slight difference is all.

VCR2 vs. Mistral J-Valve Characteristics:
- At 300-700 psi, it is possible to mistake the VCR2's increasing breathing effort for running out of air so you might pull the reserve rod too early. On the other hand, a Mistral will be at it's easiest breathing in those low 300-700 psi pressures and running out of air will be a very definite difference going from lots of air to nothing in 1-2 breaths. There will be no question that it's time to pull the J-Rod!
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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