Preventing regulator freeze up

[vam]

Yesterday four local divers and myself (I'm still to green to call myself a diver) attempted a shore dive in Lake Simcoe, Ontario at Shanty Bay. The water was in the low 30's, and there was a lot of slush to wade through just to get in the water. I was in a 7mm wetsuit and the others all had drysuits.

We lost our first diver at the shore when his regulator started to free flow and we couldn't get it under control. I'd already been advised to forgo the usual regulator check and wait until I was under water to attempt breathing from mine to prevent a freeze up. The rest of us swam out and began our descent. As soon as I tried to use mine it went into free flow. I tried tweaking the adjustment knob to no effect. I looked around to signal that I was giving up, but visibility was almost nil and I couldn't see the others even though they were only a few feet away. So I surfaced and returned to shore.

The others weren't far behind me. Every single one of us had to give up because of free flow. One diver had a pony and tried to get a few minutes with that, but it's regulator froze up too.

Now another group wants to take a stab at it, and has invited me along. Not being the sharpest tack in the box, I'm considering it. I was using a Sherwood SR2 yesterday, but thought I might try my Dive Rite XT's. Now given we were six out of six frozen last time (including the pony) I figure there's more to it than choice of regulator. It was suggested that we bring a cooler full of hot water and soak the regs in that first to give them a warm start. I don't want to do that and then have them freeze between the cooler and the plunge. The air temperature was above freezing yesterday, but the high predicted for Saturday when this group wants to go is expected to be a bit below zero.

Any other ideas? I think I've talked myself out of it just typing this post, but I'm still curious what tricks might have saved yesterday's dive.

 

[KevinNM]

Some regulators are much more resistant than others. The top one the US Navy found was a particular Poseidon reg, then a particular Mares reg.

Here's an few articles that might help
How Cold Can Scuba Regulators Become?

Cold Water Regulator Blues

Eating Crow – Safe Water Temperatures for Scuba Regulators

 

[runsongas]

sounds like everyone was already using a dry sealed 1st? metal 2nd stages (scubapro 109/156 or conshelf 14) and dropping the first stage IP might help

 

[macado]

A few things I would do if you haven't already.

Keep all regulators inside your house if it's really cold out. Don't leave them in your car overnight especially if they are already wet. You may have already done that but if I am doing any sort of diving with below freezing air temperatures I don't leave regs in my car. You also want to make sure they are very dry, low humidity environment if you can.

For all my Apeks and HOG regs I adjust all my first stages down to 120-125psi. Some people don't believe this makes a big difference but I've found it's a huge help for me.

A lot of second stages are also tuned to very low cracking effort so I also de-tune my second stages.

 

[Patoux01]

Did you all get your fills at the same place? It sounds a lot like humid air if you ask me...

 

[Stoo]

There are two broad aspects to avoiding freezeups... the design of the regulator and the way the reg is used.

As others have suggested, some regs are designed to be used in really cold water. I use the Apeks DS4/XTX50 (and 40s on stages) and have never had an issue (well, not until I had them serviced, but that's a whole other thread. Actually...)

As for the how it's used, as said above, keep them warm, try not to breath too hard or fast. Never pre-breath them on land and if they do start free-flowing, the only real solution is to shut them down, then restart...

The fact that everyone's regs had the same problem and that they all failed really early into the dive, leads me to wonder about something else. Did you all get fills at the same place? Possibly that shop's air is not as dry as it should be...

Similarly, if everyone has had their regs serviced at the same shop, then possibly the IP is set a little higher than it needs to be.

Edit: I see the humidity issue was just raised above. Great minds...

 

[tbone1004]

poseidon's ;-)

jetstream and xstreams run at a low IP of 120-125, have a big metal barrel inside of them, and don't use a normal lever to seal so they are much less prone to freezing.

 

[vam]

Interesting thoughts, thanks. I wouldn't be surprised if the air did all come from the same place. I know my own 1st stage is sealed, and that my 2nd stage is plastic. I'll check out those articles and do some googling on adjusting 1st stage IP. My regs were indoors until I left for the dive. I don't think I'll be purchasing new regulators for cold water any time soon, but its good to have a better idea what my gear can and can't do. Maybe I could rent something better for the cold.

 

[cerich]

I figure there's more to it than choice of regulator. It was suggested that we bring a cooler full of hot water and soak the regs in that first to give them a warm start. I don't want to do that and then have them freeze between the cooler and the plunge.

ahhh...yeah don't bother with the warm water soak.

 

[The Chairman]

The best way to avoid that bothersome freeze up is to soak your regs in the Florida Keys. That's where they and you will be happiest anyway. Why resist? You know you wanna!