Is finding a used HP100 basically impossible?

[elmer fudd]

You are overanalyzing this and worrying about the parameters which aren't relevant. Yes total weight matters slightly, but more importantly <where> and <how> that weight is carried are huge factors in tank selection. I would never choose a tank based on cf-gas/lb tank. In fact I have never seen anyone calculate this ratio.

I chose tanks based on:

1. How much gas the dive requires
2. Buoyancy characteristics of the tank
3. How well they fit me and how they influence my trim & weighing

In that order.

I concur. What matters to me is how much the tank weighs on my back, its buoyancy characteristics, how much air it holds and to a lessor extent its overall dimensions.

Looking at it this way, HP100s and HP80's both have some stellar numbers. HP119's, HP130's and LP72's are also pretty decent, but not quite up there with the 100's and the 80's. The 119's and 130's both hold significantly more air, but they also weigh significantly more without being significantly more negatively, so you end up packing around about 8 to 10 extra pounds. The LP72's are nice and lightweight and with a reasonable overfill hold plenty of air for shallow dives. The thing is, HP80's do everything the LP72's do and they do it all better. More air, much smaller, slightly more negative; they're just a better tank. Now if I could only find them for $25 each I'd be set.

I really don't get the appeal of the other LP tanks at all.

 

[rjack321]

Can you tell me more about these 7/8 fine threads? I have no idea what they are. I can dive DIN, but what are their specs?

Older 1990s and early 2000ish 3500psi (not 3442psi) PST "HP100s" had a different valve threading between the tank and valve. Its physically smaller than the more standard 3/4" threads used on later PST and now Worthington Hp100s as well as AL80s and most LP tanks. 7/8" valves are hard to find and rather expensive. Tumbling and O2 cleaning 7/8" valved tanks is more difficult because the hole is pretty small.

Both have identical DIN threadings. The 3/4" can be 200 or 300bar and the 200bar will be yoke convertible. The 7/8" will be 300bar only and not convertible to yoke.

 

[JimJam2]

I've looked everywhere. People sell used Alu tanks all the time, some steel LP100s and HP80s here and there, but never any HP100s. Should I just give up and pay retail for them? $400 each after tax.

OMG I wish I saw your post earlier; I just gave away my HP100 but 2 hours ago!
And we are in the same area! Anyway Wallin Dive in San Carlos might put it up for sale; it has DIN threading. You might want to give them a call (they do carry a selection of used tanks but I didn't see a HP100). It's possible that an employee bought it from the store also.

 

[Stu S.]

Owning sure beats renting dive cylinders. In two years you recoup the cost of the cylinder and could probably sell it for what you paid for it. After 2 years of use a wetsuit will have no resale value. No other dive item holds value like a tank does.

 

[LiveBait]

http://www.scubaboard.com/forums/cl...pst-steel-hp-100s-scuba-tanks-din-valves.html

another asking 450 for both...

 

[scubafanatic]

http://www.scubaboard.com/forums/cl...pst-steel-hp-100s-scuba-tanks-din-valves.html

another asking 450 for both...

...the open question with respect to HP PST tanks is will their DOT 'exemption' be renewed in spring 2011 ? As last I heard it will expire May 2011 unless someone/somewhere gets it renewed, and expiration means the tanks will become illegal to re-hydro, hence pretty much worthless lumps of steel!

 

[fuzzybabybunny]

...the open question with respect to HP PST tanks is will their DOT 'exemption' be renewed in spring 2011 ? As last I heard it will expire May 2011 unless someone/somewhere gets it renewed, and expiration means the tanks will become illegal to re-hydro, hence pretty much worthless lumps of steel!

So.... I shouldn't buy those two PSTs? What's the history behind PST and DOT exemptions?

 

[LiveBait]

...the open question with respect to HP PST tanks is will their DOT 'exemption' be renewed in spring 2011 ? As last I heard it will expire May 2011 unless someone/somewhere gets it renewed, and expiration means the tanks will become illegal to re-hydro, hence pretty much worthless lumps of steel!

Wow yeah good to know please tell us more!!

OP sorry about that... but what I mean to say is it just takes time and searching. Good deals can be had....