Preventing freeze free flow?

[Greendiver]

Ok looking for some advice from some of the more experienced members of the board...
A couple of days ago I did a shallow dive in fresh water. Water temp was 33f and air was 25f. Entered from the shore without breathing on my regulator until I had submerged, immediately after the first couple of breaths my second stage began to free flow. I surfaced and turned my air off and hung out for a couple of minutes. Turning my air on again with the regulators submerged everything was ok so we continued with the dive... A couple of times the regulator would freeze up and free flow. While not the solution I would prefer, I kinked the hose for my second to stop the flow, sort of feathering it to breath. Each time after 15-20 breathes the flow would stop and normal operation would resume. I believe it is the 2nd and not the 1st freezing as my octo didn't free flow, but I didn't breath off it either. And, the flow wasn't massive, on inhalation there was no exhaust.
All this info leads to this...
Is there anything that I can do to minimize or eliminate this as I won't / don't trust this as is for anything deeper than snorkeling depth dives. My regulator is an Aeris atmos lx. I realize that "...just get a new cold water reg set!" is the first reaction most will have. But, is that the only answer?
Enlighten this rookie, thanks!

 

[Mopar]

Does your regs have a cold water kit in them? If not check with your LDS to see if you can get them to install one. That is the only thing I would know to do.

 

[Greendiver]

The 1st stage is an environmentally sealed regulator I understand. I have slid the hose protectors away from the regulators seeing that they wouldn't allow the fittings to act as heat sinks.

edit
I just reinspected and it does have the diaphragm on the 1st and the model for the 1st is AT400.

 

[Jorgy]

First 33 degrees is real cold water..........I have only been to 34 myself.......

My own personal history......

Started with an IDI Icebreaker (packed with Chirstolube (SP?)) with Osprey metal second stage, should have been set but it free flowed no matter what I did.....

Went to a SP MK25/S550 reg with TIS and AF, it also free flowed below 38-40 degrees.........

Now I dive a Poseidon xtream and it works flawlessly.........

I don't think I have changed or improved any of my technique........

But you asked about other things to try before buying a new reg........

First breath is underwater breathing out with a soft exhale.......

Don't touch the purge.......ever...........

Try a crack the second stage softly a small slow inhale when you start to breath.......stay with soft shallow breaths.........

Go to a long hose primary........this one might be more wives tail than science.....allows air to heat up and provides a bigger reserve of 150 psi air for you to breath, so there a smaller pressure drop across the first stage.....

Reduce your IP - for SP regs in cold water 125 psi was the number......

Don't inflate your BC when you breath in.......keep the demand on the first stage to a minimum..............

Some have said get an APEX valve shutoff for your second stages.....not sure I like that one......but that way a free flowing second can be easily isolated.......

Keep you reg in cold dry air before the dive......if it is in your house then there will be more humidity in the reg than outside......when I get to dive site I let the reg sit outside on a small folding table as I gear up, not in the truck..........

Get winter air fills, tanks that are filled on very cold days have less moisture in them than warm day fills..........

Use a LP tank, the smaller the differential pressure across the first stage the less cooling of the valve there is.............

A buddy of mine takes his whole rig to the water, pressurizes it and submerges it in 2 feet for at least 20 minutes before the dive…….he gears up in the water…….he also sticks his head in the water with a snorkel to get over the ice cream headache before the dive.............

Hope this helps..........M

 

[halocline]

If you want to try a cheap experiment, get a used SP metal case 2nd stage, the model will be either "109" or "balanced adjustable." You should be able to pick one up for about $30-40, and you should get it rebuilt. It does not matter if it has the balanced (G250) poppet or unbalanced. (G200) In fact, leave it unbalanced, it will make the whole thing less expensive and more impressive when you see how well an unbalanced 30 year old reg breathes. Just put it on your existing first stage, tuned to the IP, and try another frigid dive.

I'm not sure about the lowered IP bit; I know it's a commonly suggested cold water adjustment, but it doesn't make too much sense to me. It does theoretically lower flow to the 2nd stage, but it also increases the more extreme pressure drop in the 1st stage with an accompanying adiabatic cooling increase. I guess in the interest of focusing the anti-freezing efforts on the 2nd stage it's worth a try, but unless it's really high (like 150) I seriously doubt lowering it 10 PSI or so will make much difference.

Good luck, I'd say it sounds like fun but to me the idea of diving in 33F water is anything but fun. Maybe I'll man up someday and give it a try.

 

[Jorgy]

We have a tradition of a New Years dive............so at least one really cold dive a year.......

M

 

[Hawkwood]

One option is to lower your IP to the low end of the operating range - 115 to 120 psi. It's not unheard of to do when ice diving. That, and minimizing using the regulator and inflator at the same time can help with first stage freeze-up.

 

[paddler3d]

I've seen a few regs that are called cold water regs, free flow. The only regs I haven't seen free flow yet are Apeks.

You can have your regs detuned, or tuned down to a lower IP. I've seen this work on regs that free flowed one weekend, detuned, and then work just fine after that in the same water conditions.

It may have been mentioned above, but avoid breathing from your regs until they are in the water. Inflate your BC orally before you enter the water.

 

[Greendiver]

It was on New Years day, ours was fun and hope yours was too!

About the diving cold, here is one for you... 3 of us were wet on that dive. A matter of economy, not choice! Now it was only for about 28-30 minutes but my core and arms/legs/head were fine (not including the ice cream headache for 3-4 minutes ). My fingers and toes got a bit cold but not bad. Having a warmed shelter to strip the wet gear off in makes ALL the difference.

In the beginning of Decmember we did a dive in 37f and all worked well except for a BC deflate button that leaked until I was in the water for a few minutes. But it was all good from there.

I appreciate all of the input!

 

[Jorgy]

Wow 33 degrees and wet.............

I could not do that..........

M