Solo Cave Diving: Equipment Configuration

[rddvet]

Are you cave trained? Are you certified as a diver?

I doubt his circuit board is waterproof

 

[Gone for diving]

Sounds like scubadude is doing dives like
Agnes Milowka did.

 

[PfcAJ]

Sounds like scubadude is doing dives like
Agnes Milowka did.

Tacky.

 

[InWay2Deep]

I would really love to see a picture of how the oring extruded out,

Brand new HP120 filled to working pressure. I had used it once, then filled, was going out to packup for the weekend and found it in the garage like this. September in the midwest, not super hot in the garage so shouldn't have been enough heat to overpressure the tank. I took it back to the shop, they replaced the o-ring, filled again, same thing happened again the following week. They took it back, replaced the valve and o-ring and I haven't had any issue with it since.

So while oring extrusion is rare, this right here tells me it's 100% possible.

 

[rddvet]

Brand new HP120 filled to working pressure. I had used it once, then filled, was going out to packup for the weekend and found it in the garage like this. September in the midwest, not super hot in the garage so shouldn't have been enough heat to overpressure the tank. I took it back to the shop, they replaced the o-ring, filled again, same thing happened again the following week. They took it back, replaced the valve and o-ring and I haven't had any issue with it since.

So while oring extrusion is rare, this right here tells me it's 100% possible.

No wonder it extruded you’ve got a Peter north load of lube on it.

 

[Gone for diving]

That chanfer in the tank, must be to big and close to the flat on the valve, for it have a small gap to push it through...
Don't like the valve design.

Shouldn't matter but in this case with that valve I would use a 90D oring...

 

[mdwalter]

it's complicated but @rjack321 hit it on the head pretty well.
I know of one guy who dives indy doubles who is an old local *in his 70's*, though he doesn't usually solo dive, but has always dove indy doubles since the 60's. He has a couple sets of "normal" doubles but the isolator is only opened to get them filled, closed when diving.
Bill is also the only cave diver I know who is still diving a straight crossbar.

I do a decent bit of solo diving in doubles, but it's always fairly benign caves, no more than about 1500ft of penetration and nothing terribly exciting or I'm in sidemount. Things like the first dive of the trip going to Table Rock in LR and back again, small dives compared to normal but I also do a lot of teaching so it's very rare that I actually have a "teammate" on benign dives, usually only on big stuff so it's a different mentality.

If it were me, I would just bite the bullet and go sidemount *coming from one who has been sidemount cave diving for over a decade and did all of my cave training in sidemount but still prefers doubles because I find them easier to get into and out of the water* vs indy doubles. If you go indy doubles, people will look at you funny, straight crossbars are near impossible to find, and carrying a stage on every dive is properly annoying. That said, if you do carry a buddy bottle then add a loop bungee to your harness so you can sidemount that bottle instead of having it dangle.

I could see ID as a nice interim step from BM to SM for someone who is not sure if they really want to make the jump. You could take one set of doubles and remove the center of the manifold and plug the 2 valves, then you can dive in your normal BM plate and wing with your normal regs (just add the gauge to the right side) and practice / get used to switching regs every few hundred PSI. Once you are used to the regular switching, and have determined it does not annoy you or overly task load you, it's easy to just pop off the bands and use the same tanks in side mount (at which time you will be switching out your harness and getting used to the tanks being differently located, etc) Then, it's easy to switch back and forth between SM and BM ID at will. I don't see ID as a viable final state for most people for the reasons outlined by others throughout thi thread, but it can be useful to those who are thinking about SM but not sure if they want to make the leap all at once.

 

[mdwalter]

I could see ID as a nice interim step from BM to SM for someone who is not sure if they really want to make the jump. You could take one set of doubles and remove the center of the manifold and plug the 2 valves, then you can dive in your normal BM plate and wing with your normal regs (just add the gauge to the right side) and practice / get used to switching regs every few hundred PSI. Once you are used to the regular switching, and have determined it does not annoy you or overly task load you, it's easy to just pop off the bands and use the same tanks in side mount (at which time you will be switching out your harness and getting used to the tanks being differently located, etc) Then, it's easy to switch back and forth between SM and BM ID at will. I don't see ID as a viable final state for most people for the reasons outlined by others throughout thi thread, but it can be useful to those who are thinking about SM but not sure if they want to make the leap all at once.

BTW, my own personal experience has been that I switched to SM for most of my OW diving about10 years ago, but continued in BM for cave and deep (trimix) diving for a long time after. I finally started SM in caves about 4 years ago, and I like it a lot. I am still in BM for trimix diving because I find it easier to deal with 4 or 5 tanks when 2 of them are on my back and I only have one stage and 2 deco bottles to sling (I actually side mount these instead of wearing them hanging down for better streamlining). This may change now that I have a CM rebreather. I will likely go to all SM with the RB, but if I do decide to keep some twinsets, I may decide to do ID since I won't be using them OC very much and then I can have fewer total tanks and use them all for SM or BM with the RB (or on occasion without).

 

[Tracy]

Brand new HP120 filled to working pressure. I had used it once, then filled, was going out to packup for the weekend and found it in the garage like this. September in the midwest, not super hot in the garage so shouldn't have been enough heat to overpressure the tank. I took it back to the shop, they replaced the o-ring, filled again, same thing happened again the following week. They took it back, replaced the valve and o-ring and I haven't had any issue with it since.

So while oring extrusion is rare, this right here tells me it's 100% possible.

Anything is possible when they are assembled incorrectly. There shouldn't be lube on that O-ring. There really doesn't need to be lube on the threads either, but a scoshe is acceptable. The qty laying on your tank neck would do at least 5 valves.

 

[InWay2Deep]

Anything is possible when they are assembled incorrectly. There shouldn't be lube on that O-ring. There really doesn't need to be lube on the threads either, but a scoshe is acceptable. The qty laying on your tank neck would do at least 5 valves.

Yea, that is also what the shop said. Like most, I didn't assemble the valves as the tank came to me full. So I'd venture the guess that almost nobody knows how much lube is on their valve o-rings. The point here is it's possible to extrude that o-ring either through incompetence or bad luck. I guess the up side is it did fail pretty soon after fill (although it was almost a week). So if you have tanks you've been using for a bit you can be confident they should continue to be fine, but clearly, the risk is always there.