what full face masks

[Lost Yooper]

I guess the problem I'm having with it is the 2 deco gas switch you're after. The only gas that might warrent a FFM is O2 at 20' and IWR procedures. This isn't all that uncommon for long durations and doesn't require a block of any sorts. However, you're talking about doing one heck of a dive to actually require such an O2 duration and thereby make a FFM worthwhile, I think.

The scariest thing that could go wrong with what you are doing is accidentally plugging in O2 at you're 70' stop instead of 50% (for example). As we all know, accidentally switching high PPO2 gasses was a leading cause of death among technical divers. You cannot rely on color, location, or gimmicks to ensure you don't make this mistake. Keep this in mind.

I don't think you need a shrink yet .

Mike

 

[trymixdiver]

Uncle Pug


As far as operator error i think i am very safe. However, i guess its possible if i am narced to go ahead and connect a deco mix and then breath from it at depth. Not going to say its impossible, but unlikely. I carry 2 OMS 45's for deco.

If i lost a LP hose that attaches to my side block from under my left arm i would not know which first stage to shut down because i cant see the broken hose, I could feel it if it were close to the side block, but if its highier on the hose i wouldnt be able to see or feel it. i could shut them down one at a time to determine whitch has blown but this would waste valuable time and gas but at this time this is my best option.

And like i said before i am not sure about the valves exposure to salt water and what this will do to the block over time. Will the valves fail and leak deco mix. Another drawback to this is the maticulous cleaning i have to do after diving, it requires alot of cleaning.



Hope this is what you are looking for, all i can think of at this time.

My total dive times rang from 2 to 3 hrs. my deco at 20" is on 100% yes.

 

[Uncle Pug]

Originally posted by trymixdiver
Hope this is what you are looking for, all i can think of at this time.

Here are some questions that I had ready for you:
Where is the side block located?
Can you see it while switching?
What do each of the valves control?
What keeps water out of the quick connect?
What keeps water out of the block should a valve be accidentally turned
without the QD attached?
Why do you want a FFM?
How do you plan to deal with air sharing?
Do you carry an extra mask?
Do you practice air sharing on a regular basis?
Do you practice air sharing while doing ascents with deco stops?
How many deco gases are you using?
Are all switches being handled by the block?
Are your profiles such that multiple gas switches are really required?
Are diving Heliium mixtures?

 

[Savitar]

Hello again,

With the Neptune mask you can attach a total of 3 regs.

Center for main, left and right for deco. you can select which gas at the k-valve or use the reg adjust to increase the effort of one and lessen the other.

Also, you can tell which reg is 'on' (lft,rht,or center)

Maybe I broke some rules, but I did my octo like this.

Please correct me if I'm dangerous.

I also carry a standard face mask, and a mouth peiced reg anytime I use a ffm. I can ditch everything, and be able to use anybodys bailout rig to get out of a jam.

happy days,
Warren

 

[Uncle Pug]

Hi Warren,

Are there any failure modes that you can identify with your FFM set up??

Why is it that you want to dive a FFM?

Do you practice OOA air sharing on a regular basis?

How does it go?

 

[trymixdiver]

Located on my left side attached to my weist harness belt

Yes i can see it when switching.

3 valves. valves 1 and 2 control main gas from doulbles, vale 3 controls deco mix on and off when connected.

The design of the quick connect keeps water out, however i get a tiny mist when i first connect to the deco bottle. just a short mist, whats trapped in the connector, say a tea spoon.

water canted enter the block, 3 LP hoses are attached to the valves. 2 go to the 1st stages of the of the doubles the third is connected to a quick disconnect which is a female. this female is connected to the 2 males attached to the deco bottles. but not until needed.

I like the FFM comfort, warmth and comms use. Figured if i took a hit it couldnt hurt either.

I do still carry a long hose reg as a backup to my FFM and for a buddy.

Yes i carry a back up mask

I dont practice it too much because i dive with only one person and we know each others config. We know each others rig like its our own. We have set this configuration up together, tested it in the pool many times. Infact we did all our cert dives for tech nitrox and tech deep air useing this configuration. As you know from the pool and ocean work for those classes we are highly familiar with our equipment.

air sharing while at deco stops we dont practice.

2 deco gases 50% and 100%

all gas switching is done thru the block yes. once i get to 20' i disconnect my 50% and connect my 100% o2.

are multiple gas switches really needed. personnally i think they are in my case. we are beach diving with 4 tanks diving a wall. lot of work getting in and out i think we need the 2 deco mixes based on exertion, cold, and dive time.

no He.

 

[Savitar]

hey guys,

here's a few pictures of diver/inventor Tony Maffatone using a rig he designed to mix his gas on the fly, duing his dive!

http://www.tonymaffatone.com/Tony photo gallery/index.htm


This in no way should be construed to endorse building your own gear.

dive safe,
Warren

 

[Uncle Pug]

Try...

I think your inner voice is trying to tell you something....
Best to listen to that inner voice...

 

[Savitar]

Originally posted by Uncle Pug
Hi Warren,

Are there any failure modes that you can identify with your FFM set up??

Why is it that you want to dive a FFM?

Do you practice OOA air sharing on a regular basis?

How does it go?

I believe I'm fairly redundant what with my ffm with two regs, and another long hose octo on a bailout bottle and spare mask.

I've done ffm diving for several years, my wife teases me when I show her my old gear, saying it's older than she.
I'm more comfortable with ffm especially in cold water.
I love the comm, for teaching, rescue, sightseeing....

Not only do I practice OOA air sharing on a regular basis, now that my wife is diving, we play in the pool 3 or 4 times a week.
(I've got an indoor pool, and my own compressor)

happy days,
Warren

 

[Uncle Pug]

Unless I missed it...
And that is a possibility...
No one has identified the failure modes...
That doesn't mean that failure modes don't exist...
It is possible to prepare for failures that are unlikely...
While remaining oblivious to failures that are likely...
Ask yourself, "What could go wrong?"

Oh, and Try...
What is happening inside your second stage with each blast of saltwater? What could happen because of this? How do you mitigate this?