Spare Air – The Best Item in Your Scuba Toolbox

[dumpsterDiver]

There was a lot of manufacturing variation to start with, often above and below the 300-500 PSI spec. I was pretty young and gave up on J-valves before learning to rebuild valves or regulators. Guys in the Vintage Forum are more up on the nuts & bolts. Like you, my first guess would be the stainless spring is the major culprit.

I had them wear out. As I recall, the part that rotated was plastic and wedge shaped and would wear, not seal up effectively and eventually not even move on and off. It has been a while, but they were a pain in that the tank filler needed to remember to put the reserve in the down position to fill, or the tank didn't get filled.

Once we got pressure gauges, the reserve was stupid, so I taped it in the down position, but they also tended to leak.

 

[Akimbo]

Combine it all. Deep spare air while wearing a horse collar BC.

As much as I didn’t enjoy using them, a horse collar emergency buoyancy device is probably the best thing an unconscious or lost-at-sea diver can be in. They were basically oversized inflatable life jackets and securely floated your head out of the water far enough to take a nap.

It is worth understanding what is good and bad about every piece of gear so you can make an informed decision and keep those compromises in mind as you use it and look for upgrades. Nothing is perfect.

---------- Post added November 28th, 2014 at 06:55 PM ----------

Never having used a J-valve, I found this whole discussion enlightening. I was thinking exactly what you wrote here when I was reading.

I am flattered that you found it useful.

 

[Akimbo]

I had them wear out. As I recall, the part that rotated was plastic and wedge shaped and would wear, not seal up effectively and eventually not even move on and off….

Interesting, all the ones I used were all metal including the handles. The US Navy still spends big bucks on a low-production double manifold with a single center valve and regulator port and a PLASTIC reserve lever. Our tax dollars at work.

 

[dumpsterDiver]

The inside portion is what would wear out. The actual external piece that moved up and down was brass on my valves.

 

[RJP]

Combine it all. Deep spare air while wearing a horse collar BC.

 

[Max Speed]

Just got back from a trip. Used two joined and slung spare airs. Easier to pack in checked luggage and lighter weight than a 19 cf pony. If needed the first one will get me to 60 feet from the approximately100' planned depth. The second will get me to the surface. Non deco dives. Works fine. Nice product.

If I can drive to my job site, I will however, carry a 19-40 pony instead.

 

[redacted]

Just got back from a trip. Used two joined and slung spare airs. Easier to pack in checked luggage and lighter weight than a 19 cf pony. If needed the first one will get me to 60 feet from the approximately100' planned depth. The second will get me to the surface. Non deco dives. Works fine. Nice product.

If I can drive to my job site, I will however, carry a 19-40 pony instead.

But heavier and harder to carry than a 6 cu ft pony so WHY?

 

[rhuntley]

Just got back from a trip. Used two joined and slung spare airs. Easier to pack in checked luggage and lighter weight than a 19 cf pony. If needed the first one will get me to 60 feet from the approximately100' planned depth. The second will get me to the surface. Non deco dives. Works fine. Nice product.

If I can drive to my job site, I will however, carry a 19-40 pony instead.

A diver wearing two spare airs? That'd be a sight..

 

[Max Speed]

I'll get a photo next time.

---------- Post added December 3rd, 2014 at 01:03 AM ----------

But heavier and harder to carry than a 6 cu ft pony so WHY?

Two little things pack better than one big plus a reg.