double 104's

[Karl_in_Calif]

lal7176 once bubbled...
Its called redundancy. Since when is redundancy a bad thing? There is nothing wrong with carrying some extra gas at the end of a dive even when diving within NDL. I would rather surface with a 1000psi in my double 72's than drown from lack of air cause an emergency came up with me or my buddy.

What happens when a hose bursts when diving your single tank and your same ocean buddy has wandered off. You better hope its a slow leak and you can make it to the surface before depleting your tank or blow and go heading to the surface.

I simply shut down the affected post on my 72's and make a nice controlled ascent.

LAL you are right about the redundancy, but he wants to wear twin steelies with his wetsuit, and in particular twin 104s.

I would certainly agree with you that smaller twins would give him redundancy, although I question whether this is a good idea with a wetsuit, and therefore a single steel tank together with a redundant aluminum stage tank would seem to be better, with his wetsuit.

lal7176 once bubbled...
...you registered this month...

not exactly!

 

[FIXXERVI6]

I do have a semi dry, but the water is still too warm for it.

Why doubles? after looking at the benefits I'm more apt to ask why not?

More gas, better more than less, more redundnacy, I love the thought of the redundancy, better weight distribution.

I wouldn't mind double aluminums, after this thread and talking to some locals I may end up with aluminum, but I am drooling over LP steels, even if they are just 80's, but if I could make 95's or 104's work, that would make me very happy

I do plan on driving for most of my diving, even to florida, and I have a trip scheduled, to drive there in the spring.

 

[Karl_in_Calif]

FIXXERVI6 once bubbled...
I wouldn't mind double aluminums, after this thread and talking to some locals I may end up with aluminum, but I am drooling over LP steels, even if they are just 80's, but if I could make 95's or 104's work, that would make me very happy

I do plan on driving for most of my diving, even to florida, and I have a trip scheduled, to drive there in the spring.

Before you buy gear, it would be a good idea to look around town to find out what tech agency you may decide to go with. Then ask them what gear they will require. That way you will not waste a lot of money on a lot of gear that you would need to replace later.

Twin 104s are really popular with GUE. They also like steel backplates and shell drysuits. And they prefer Halcyon or DiveRite B/Cs. And they absolutely hate bunjeed wings.

Outside of GUE, I have seen twin 72s, twin 80s, twin almost anything on tech divers.

Outside of GUE there is IANTD, NAUI, TDI etc. So it may help to do your homework locally before you buy.

 

[Don Burke]

FIXXERVI6 once bubbled... I do have a semi dry, but the water is still too warm for it.

I think you'll do fine with the 80s and an aluminum backplate. A steel plate would be too much for that 3mm suit. Having a steel plate just for the semi-dry would be pretty extravagant.

FIXXERVI6 once bubbled... Why doubles? after looking at the benefits I'm more apt to ask why not?

If you ever want to get under something, the redundancy will be a major plus.

FIXXERVI6 once bubbled... I wouldn't mind double aluminums, after this thread and talking to some locals I may end up with aluminum, but I am drooling over LP steels, even if they are just 80's, but if I could make 95's or 104's work, that would make me very happy

I know how you feel. I've been fumbling around trying to figure out a safe way to dive my 72s wet. I may have to build my own backplate out of epoxy with some balsa sandwiched in. 95s and 104s are just plain out of reach for the safety factors I want.

FIXXERVI6 once bubbled... I do plan on driving for most of my diving, even to florida, and I have a trip scheduled, to drive there in the spring.

In any case, doubles are pretty tough to rent in many places.

 

[FIXXERVI6]

http://scubatanks.us/scuba_tanks.htm

the faber LP95 listed there goes positive when empty, and it is steel.

+2.5 empty and -4.4 empty

With doubles on those I'd have to wear a few pounds of lead, aluminum backplate of course.

Still too much weight for wet suit?

 

[Don Burke]

FIXXERVI6 once bubbled... http://scubatanks.us/scuba_tanks.htm

the faber LP95 listed there goes positive when empty, and it is steel.

+2.5 empty and -4.4 empty

With doubles on those I'd have to wear a few pounds of lead, aluminum backplate of course.

Still too much weight for wet suit?

I doubt those numbers are correct. All of the Faber cylinders about that size shown on the OMS site are negative.

http://www.omsdive.com/cyl_spec.html

One of the harsh realities of dive cylinders is that the specifications, especially the buoyancy figures, are hard to pin down. At three hundred-something each for Fabers, it could be an expensive lesson.

If you can get a chance to actually dunk the LP95s before you buy one, it's worth a try. I wouldn't buy them sight unseen.

 

[Dryglove]

LAL you are right about the redundancy, but he wants to wear twin steelies with his wetsuit, and in particular twin 104s.

I could not imagine lugging around 104's for rec use. My steel 72's or even a set of LP80's would be as big as i would go. I can easily dive and walk around with my 72's and only feel a slight weight difference on dry land compared to a LP104.

With my steel 72's i still need need 9lbs of weight to be neutral at 10ft with 250 psi in my tanks. I can wear that in a belt or a v-weight. I choose the v-weight as i hate weight belts and have an inflation hose coming off of each post to my drysuit and wing. I can easily swim my my rig up from depth. I think i could still swim them up easily in a wetsuit but would wear the extra weight in a belt in case of wing failure to help flotation at the surface . The main thing is to be properly weighted and wear ditchable weight in a wetsuit or use a dual bladder wing or double wing setup.

I see no problem with wearing smaller steel tanks with a wetsuit as long as you are not negative at 10 ft with near empty tanks and have some form of ditchable weight in case of wing failure to give yourself more flotation on the surface.

The problem with 104's and a wetsuit is that you are more than likely still very negative with near empty tanks at 5-10ft with no ditchable weight and the weight of the gas in the tanks meaning it makes it very hard if not impossible to swim those monsters up from depth not to mention trying to stay on the surface and not sink back under. But there is always the double wing option or dual bladder option.

not exactly!

According to your current user name you registered this month. Why the change of name?

I think you'll do fine with the 80s and an aluminum backplate. A steel plate would be too much for that 3mm suit. Having a steel plate just for the semi-dry would be pretty extravagant.

That would be a great setup for a warm water diver. Double 104's in a 3mm would be crazy.

 

[boomx5]

Karl_in_Calif once bubbled...
Twin 104s are really popular with GUE. They also like steel backplates and shell drysuits. And they prefer Halcyon or DiveRite B/Cs. And they absolutely hate bunjeed wings.

Outside of GUE, I have seen twin 72s, twin 80s, twin almost anything on tech divers.

Within GUE I have seen aluminum backplates double 80s, double 95s (which I use), and steel 72s. It depends on the application but I've seen GUE instructors use all these things.

 

[FIXXERVI6]

ok.... how about double aluminum 100's, just about the same bouancy as 80's.

would a 45# wing be good enough for double 100's and an aluminum back blate?

 

[Dryglove]

FIXXERVI6 once bubbled...
ok.... how about double aluminum 100's, just about the same bouancy as 80's.

would a 45# wing be good enough for double 100's and an aluminum back blate?

If you are properly weighted so you are neutral at the end of your dive with almost empty tanks a 45lb wing should be good with a 3mm suit as there isnt much buoyancy loss from compression at depth. Basically you are offsetting the weight of the gas in your tanks plus any buoyancy loss from your wetsuit at depth.

I dive double steel 72's and just recently switched over to a 45lb wing from a 55lb wing. The 45lb wing works great for me. I think i remember a post where roakey said he can use a 45lb wing with his double 104's. You might check with him on that for sure as i dont dive any tanks that big or heavy.

Also remember it is a very good idea to have some ditchable weight in case of bladder failure in a wetsuit for surface flotation. This needs to be figured in with your buoyancy check with near empty tank and dont purposely overweight yourself just so you have weight to ditch as it defeats the purpose. Its not like a drysuit where you can just add air to your suit for extra surface buoyancy in case of bladder failure.

If your not gonna use a double bladder wing you need to be able to swim up your rig or carry a lift bag that you can vent expanding air like the halcyon if you use it for an ascent. I have read several ways of using a lift bag or combintion of a lift bag/reel for bladder failure. The lift bag/reel consisted of shooting a bag then reel yourslef up to the bag on the surface. I personally use a drysuit, wing, plus a lift bag that is mostly used as a surface marker and only dive isolated manifolded doubles. I have never tried using the bag for an ascent to the surface and dont think i would want to.

I have seen people use double alm 80's but i dont think i have ever seen anyone dive double alm 100's. Why that is i have no idea. I do know they are some big tanks. I hope you have strong back and legs