Dust Cap Waterproof?

[Mortlock]

How effective is the dust cap in keeping water out of your 1st stage when you soak it after use? It doesn't seem to be watertight to me but is it good enough for the purpose of soaking in a tub?

Thank you,

Morty

 

[hex92]

The dust caps on my scubapros seem to keep the water out of the first stage.

 

[nativenarcosis]

The caps are supposed to keep the water out of the 1st stage. If they do not you may have a defective one or one not suited for your particular reg.

 

[Mortlock]

Sorry, please allow me to explain little better. I don't really know if it's watertight or not. It's just that when I inhale on my second stage when the 1st isn't attached to a tank then I can draw in a bit of air through the edges of the dust cap. If I take the dust cap off, put my thumb over the hole and try to inhale, I can't. This is what makes me believe it isn't watertight. Is this normal though?

I have a DR RG2000 reg setup and if I take the yoke adaptor off and put the dust cap over the DIN threads then I can't inhale through the 2nd .

Thankyou,

Morty

 

[miketsp]

Sorry, please allow me to explain little better. I don't really know if it's watertight or not. It's just that when I inhale on my second stage when the 1st isn't attached to a tank then I can draw in a bit of air through the edges of the dust cap. If I take the dust cap off, put my thumb over the hole and try to inhale, I can't. This is what makes me believe it isn't watertight. Is this normal though?

Morty

Wow, you must have lungs of steel. :11: You say you can crack both 1st and 2nd stages without a tank?
My 1st reaction is they're defective. I didn't think that was possible on a normally adjusted setup without at least 20bar/280psi pressure coming from the tank to help open the valves!

Coming back to the subject, most dust caps have an o-ring and should seal perfectly, unless you have lost your o-ring during the dive. I got fed up replacing lost o-rings so I bought rubberised dust caps (semi rigid rubber) and the seal is perfect without risk of loss.

 

[matt_unique]

Dust caps keep out dust but they are not water tight. You should always rinse your regs connected to a tank and pressurized to ensure water stays out of the first stage.

When I first began diving I soaked my regs with just the dust cap. After an annual service the tech said water ran out of my first stage - it was completely flooded. The next time in the water I could not believe how much better the reg was breathing. When water slowly leaks into your first stage it will diminish the performance gradually so you probably will not notice it.

--Matt

 

[Rick Murchison]

Wow, you must have lungs of steel. :11: You say you can crack both 1st and 2nd stages without a tank?
My 1st reaction is they're defective. I didn't think that was possible on a normally adjusted setup without at least 20bar/280psi pressure coming from the tank to help open the valves!

No, with no IP the first stage is wide open. Cracking pressure on the second stage is only slightly higher with no IP than with normal IP.
While there is considerable resistance to airflow through the regulator and an inhalation at a normal rate isn't usually possible, it is quite easy to crack the second and get flow.
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However, if you can get flow around an installed dust cap, it isn't sealed against water.
Rick

 

[Mortlock]

Yep, it's not like I'm getting a good flow of air when I do this but I am getting some.

What I'm really getting at here is should I soak my regs and rely on the dust cap to keep the 1st stage dry? Matt_Unique certainly doesn't believe so. Anyone else?

If not, what's the best way for me to rinse down my regs after a dive?

Thanks for the help,

Morty

 

[Rick Murchison]

If not, what's the best way for me to rinse down my regs after a dive?

Personally I like to use a garden hose with the reg attached to the tank and pressurized rather than soak.
Rick

 

[miketsp]

No, with no IP the first stage is wide open. Cracking pressure on the second stage is only slightly higher with no IP than with normal IP.
While there is considerable resistance to airflow through the regulator and an inhalation at a normal rate isn't usually possible, it is quite easy to crack the second and get flow.
Rick

Of course you're right, I didn't stop to think it through - bad habit.
I was just remembering the time I tried to suck a reg without a tank and just tore the rubber diaphragm in the (well used & ancient) 2nd stage before I got any flow.