What size doubles?

[rjack321]

Mr. Bubble are you in a wetsuit or dry?

 

[Mr. Bubble]

Well, the weight and displacement should be nominal between the two tanks +/- 4 lbs. and one inch. Exposures would include full recreational to 130 with possible advanced nitrox to 150. I don't see myself going much deeper than that any time soon.

 

[xiSkiGuy]

Well, the weight and displacement should be nominal between the two tanks +/- 4 lbs. and one inch. Exposures would include full recreational to 130 with possible advanced nitrox to 150. I don't see myself going much deeper than that any time soon.

Between which two tanks? Don't forget gas has a weight, too. In double 130s the 260cf of air weighs 20lbs. 170cf in 85s weighs about 13lbs.

By exposure protection we mean wetsuit or drysuit and what kind?

 

[Doc Intrepid]

With respect to who makes a high-pressure example of a LP95, the answer is PST with their E8-119. Unless I'm mistaken, Worthington also makes such a tank, but the dimensions are different.

You may be missing one of the more important criteria -

Steel tanks should be purchased such that the diver can balance out wearing them. They have to work for the individual body type, weight, size, etc. of the diver.
All other considerations are secondary.

I first purchased a set of E8-119s (HP95s). I could not get them to work for me - they put too much weight above my COG. I exchanged them for a set of E8-130s. Perfect balance.

Whatever you buy needs to work FOR you, not against you.

This is why it's optimal to borrow a set of tanks from several of your buddies, and dive them in confined water ~20 fsw or so. At these depths all your errors will compound and be instantly noticeable. Once you find a set of steel tanks that works for you here - allows you to position yourself perfectly, no matter how large or small they are - buy a set of those, whatever they are.

Learning doubles is hard enough without getting a set of tanks for reasons of cost, size, brand, length, or whatever else - but with complete disregard for how you dive wearing those specific tanks.

Learn what fits you first. Buy those.

Everything else is less important than what works well for you underwater.

Here are the specs for PST tanks, including the "HP 95s" (E8-119):
http://www.lloydbaileysscuba.com/PST E Series Tanks.htm

Good luck...

 

[nereas]

With respect to who makes a high-pressure example of a LP95, the answer is PST with their E8-119. Unless I'm mistaken, Worthington also makes such a tank, but the dimensions are different.

You may be missing one of the more important criteria -

Steel tanks should be purchased such that the diver can balance out wearing them. They have to work for the individual body type, weight, size, etc. of the diver.
All other considerations are secondary.

I first purchased a set of E8-119s (HP95s). I could not get them to work for me - they put too much weight above my COG. I exchanged them for a set of E8-130s. Perfect balance.

Whatever you buy needs to work FOR you, not against you.

This is why it's optimal to borrow a set of tanks from several of your buddies, and dive them in confined water ~20 fsw or so. At these depths all your errors will compound and be instantly noticeable. Once you find a set of steel tanks that works for you here - allows you to position yourself perfectly, no matter how large or small they are - buy a set of those, whatever they are.

Learning doubles is hard enough without getting a set of tanks for reasons of cost, size, brand, length, or whatever else - but with complete disregard for how you dive wearing those specific tanks.

Learn what fits you first. Buy those.

Everything else is less important than what works well for you underwater.

Here are the specs for PST tanks, including the "HP 95s" (E8-119):
http://www.lloydbaileysscuba.com/PST E Series Tanks.htm

Good luck...

Doc, I have heard from everyone that PST is temporarily out of business while they relocate their manufacturing facilities overseas to Asia. In the meantime it is virtually impossible to get tanks from them. It may be all urban legend, but so far that is what everyone has been saying.

 

[xiSkiGuy]

Doc, I have heard from everyone that PST is temporarily out of business while they relocate their manufacturing facilities overseas to Asia. In the meantime it is virtually impossible to get tanks from them. It may be all urban legend, but so far that is what everyone has been saying.

With respect to who makes a high-pressure example of a LP95, the answer is PST with their E8-119. Unless I'm mistaken, Worthington also makes such a tank, but the dimensions are different.

Worthington makes the X8-119 and Faber makes the FX-117. Similar to LP95s/LP98s.

I'm pretty sure no one has PST stock right now.

 

[nereas]

What size wing would be best? 45,60, 85,90? Remember, I may have some stage bottles as well.

Thanks

The stage bottles are virtually neutral so those do not normally need to factor into the wing equation. I recently did the math on this, and here is what I got for double tanks:

-6.0 lbs backplate
-4.0 lbs 2 regs
-2.0 lbs tank bands
-4.0 lbs manifold
-2.0 lbs tanks (empty)

-18 lbs gross neg buoyancy without backgas

Onto this -18 lbs you then need to compute the weight of your backgas mix at roughly 0.08 lbs per cu ft.

Twin 85s = 170 cu ft = -13.6 lbs

So for you that equals a minimum of 32 lbs lift capacity for your wing.

The next highest available Oxycheq wing is 40 lbs. Their prices and quality are pretty good.

 

[nereas]

Worthington makes the X8-119 and Faber makes the FX-117. Similar to LP95s/LP98s.

I'm pretty sure no one has PST stock right now.

Glad I bought my PSTs when I did.

 

[cool_hardware52]

The stage bottles are virtually neutral so those do not normally need to factor into the wing equation. I recently did the math on this, and here is what I got for double tanks:

-6.0 lbs backplate
-4.0 lbs 2 regs
-2.0 lbs tank bands
-4.0 lbs manifold
-2.0 lbs tanks (empty)

-18 lbs gross neg buoyancy without backgas

Onto this -18 lbs you then need to compute the weight of your backgas mix at roughly 0.08 lbs per cu ft.

Twin 85s = 170 cu ft = -13.6 lbs

So for you that equals a minimum of 32 lbs lift capacity for your wing.

This is only 1/2 the answer. Without knowing the buoyancy of the divers suit you cannot size a wing.

Tobin

 

[nereas]

This is only 1/2 the answer. Without knowing the buoyancy of the divers suit you cannot size a wing.

Tobin

I gave the drysuit answer, yes. And with a drysuit, he would be able to keep his suit neutral at all depths, of course.

With double steel tanks he should not be diving in a wetsuit. That is probably a different thread. Or else someone can take up that gauntlet here.

Thanks, Tobin. Good point.