Is finding a used HP100 basically impossible?

[Tug]

there were 4 up on eBay today for 175 each, I think they went for around 200 each. If you keep your eyes open the occasional 100 pops up.

 

[fuzzybabybunny]

I just pulled the specs on the major steel cylinders from this site:

TECHDIVINGLIMITED.COM

I put the data into excel and made a quick formula that calculated the capacity to cylinder weight ratio. The good ones have about 3 cubic ft/lb and the worst has 1.88 cubic ft/lb. The Worthington X7-100 truly is the best out there for a 100 cuft tank. 3.03 cuft/lb, and the most negatively buoyant out of the 100s that have close to this ratio, so its weight to capacity is very efficient + it allows you to carry less weight on the belt.

In comparison, low pressure tanks in the 100 range are only at 2.6 cuft/lb max, weigh more, are physically larger, and aren't as negatively buoyant.

 

[Gombessa]

I was originally referring to any LP tank that was around the 100 mark.

I see. It's probably best to be as specific as possible when you're talking about tanks, there are a lot of different ones out there and pricing/availability can differ dramatically between them.

I'll keep my eyes peeled on eBay and Craigslist... I'll just be spending more money renting as I wait.

Craigslist in the bay area always yields good tank deals regularly.

FYI, you don't spend much more money renting tanks here over buying them. A rental typically costs $8 or so, which is just a couple bucks more than a fill. Add to that the yearly vis and 5-year hydro costs associated with owning tanks, and it's a long time before you break even. IMO the biggest benefit of owning tanks is convenience (you dive when you want with the gear you want, without having to pick up/return rentals which may be different capacities each time).

 

[Tug]

FYI, you don't spend much more money renting tanks here over buying them. A rental typically costs $8 or so, which is just a couple bucks more than a fill. Add to that the yearly vis and 5-year hydro costs associated with owning tanks, and it's a long time before you break even. IMO the biggest benefit of owning tanks is convenience (you dive when you want with the gear you want, without having to pick up/return rentals which may be different capacities each time).

wow, wish I had those prices by me. A rental tank is usually double that if not triple that amount

 

[Gombessa]

wow, wish I had those prices by me. A rental tank is usually double that if not triple that amount

I think in Hawaii, many ops include any and all gear you may need (wetsuit, bc, regs, tanks, computer fins, weights etc.) in the cost of the charter. Grass is always greener somewhere, right?

 

[Tug]

I think in Hawaii, many ops include any and all gear you may need (wetsuit, bc, regs, tanks, computer fins, weights etc.) in the cost of the charter. Grass is always greener somewhere, right?

ain't that the truth! that said, I love it where I am and will gladly take the bad with the good

 

[fuzzybabybunny]

FYI, you don't spend much more money renting tanks here over buying them. A rental typically costs $8 or so, which is just a couple bucks more than a fill. Add to that the yearly vis and 5-year hydro costs associated with owning tanks, and it's a long time before you break even. IMO the biggest benefit of owning tanks is convenience (you dive when you want with the gear you want, without having to pick up/return rentals which may be different capacities each time).

A couple of thoughts:

Rental: ~$7 a day. Fills are $6, $5 if you buy a fill card worth 10 fills. Hydro costs $45. Visual costs $15.

Say I dive 20 days out of the year. Rental costs would be $140.

I buy a used tank for $200, visual it for $15 after a year, put $10 that year towards hydro-ing in a few years, and I've got $225.

In two years I can recoup the cost of the cylinder. Afterwards I would only need to dive enough to recoup the costs of the inspections.

Buying used means more convenience, and you don't run the risk of filling up a rental, not being able to dive on it for whatever reason, and having to return it with a full wasted fill. Plus you can sell your tank again in the future for almost the same price you bought it for originally.

 

[CT Sean]

A couple of thoughts:

Rental: ~$7 a day. Fills are $6, $5 if you buy a fill card worth 10 fills. Hydro costs $45. Visual costs $15.

Say I dive 20 days out of the year. Rental costs would be $140.

I buy a used tank for $200, visual it for $15 after a year, put $10 that year towards hydro-ing in a few years, and I've got $225.

In two years I can recoup the cost of the cylinder. Afterwards I would only need to dive enough to recoup the costs of the inspections.

Buying used means more convenience, and you don't run the risk of filling up a rental, not being able to dive on it for whatever reason, and having to return it with a full wasted fill. Plus you can sell your tank again in the future for almost the same price you bought it for originally.

I agree with the sentiment of owning your own tanks, I plan to do so when money allows. Your yearly cost is off however, I think you are forgetting to factor in the cost of the 20 fills ($100) for that year of diving.

Using your #s it actually takes about 12 years for the tank to pay for itself.

 

[fuzzybabybunny]

I agree with the sentiment of owning your own tanks, I plan to do so when money allows. Your yearly cost is off however, I think you are forgetting to factor in the cost of the 20 fills ($100) for that year of diving.

Using your #s it actually takes about 12 years for the tank to pay for itself.

I dive for 20 days (let's say 10 weekends) so I would have to pay for 10 fills if I bought tanks versus rented them for 10 weekends. $50.

 

[rjack321]

I just pulled the specs on the major steel cylinders from this site:

TECHDIVINGLIMITED.COM

I put the data into excel and made a quick formula that calculated the capacity to cylinder weight ratio. The good ones have about 3 cubic ft/lb and the worst has 1.88 cubic ft/lb. The Worthington X7-100 truly is the best out there for a 100 cuft tank. 3.03 cuft/lb, and the most negatively buoyant out of the 100s that have close to this ratio, so its weight to capacity is very efficient + it allows you to carry less weight on the belt.

In comparison, low pressure tanks in the 100 range are only at 2.6 cuft/lb max, weigh more, are physically larger, and aren't as negatively buoyant.

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.