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bigman241
12-29-2009, 14:11
I am preparing to get my ow cert. There are quit a few local quarries I can dive but no dive shop for 60 or 80 miles. I see no reason to run almost 2 hours out of my way to rent gear so after the cert class I am going to pick up all my gear. I also see no reason to spend a bunch of money on gear and still need to drive 2 hours to rent tanks so I want to get at least one if not two tanks. The issue is I can not figure out if I should go with a steel or alum tank. I know with steel you can go hp so more air bigger tank. With me being a big guy that is a big plus. I know alum is cheaper by about half so I could buy about 4 alum 80s for what the steel 130s are for 2.
What are the pros and cons to each? What do you use?
Also I noticed scubatoys have a good deal on double tank setups you get two tanks and the manifold to hook them up for a good price. Would it be worth buying the double setup if I do not plan on going doubles for a few years? The manifold would just sit around for a few years or maybe a year but it would save close to 150 bucks I think.

comet24
12-29-2009, 14:48
I prefer steel over Al for a few reason. Buoyancy characteristics and amount of gas they hold.

If your just starting out Al are the way to go if cost is factor. If not then you may want to look at steel. Steel 130's are heavy tanks about 43lbs empty. Think about that if you have to do some walking at your local quarry. The positive is you can carry less weight.

Buy doubles and breaking them apart as you say is fine if your going to head down that road later. Also remember though, at that point, your more then likely need some Al tanks for stage/deco.

On other thing most HP tanks are going to be DIN although many may have screw in adapters for yoke.

Vercingetorix
12-29-2009, 15:08
I bought the neutral buoyancy AL tank from ST, because cost was a factor. If cost is not a big factor for you, go steel for the additional capacity. You don't need to go to 130 cf. Go with a 100cf or so. Doubles are usually made from two 100cf, so a single one today can migrate to doubles in the future.

bigman241
12-29-2009, 15:13
Most of the quarries I will be on are strip pits from coal mining. Most if not all are drive up by the water. The main one I plan on diving has two ramps one with a steep slope down to about 60 or 70 feet the other is a slow slope that goes from shore to 10 feet in about 30 feet. It in fact is hard to get a boat in if it is a big boat cause of the shallow slope. Being a big guy I will need alot of weight so I think the steel will help there. I am planning on the flathead 7 reg which comes in both din and yoke. I figured I would buy the din setup and the din to yoke adapter. Since 90% of my dives will be local and with my own tanks.
I prefer steel over Al for a few reason. Buoyancy characteristics and amount of gas they hold.

If your just starting out Al are the way to go if cost is factor. If not then you may want to look at steel. Steel 130's are heavy tanks about 43lbs empty. Think about that if you have to do some walking at your local quarry. The positive is you can carry less weight.

Buy doubles and breaking them apart as you say is fine if your going to head down that road later. Also remember though, at that point, your more then likely need some Al tanks for stage/deco.

On other thing most HP tanks are going to be DIN although many may have screw in adapters for yoke.

bigman241
12-29-2009, 15:14
cost is a little factor but not much. I see no issue in getting one steel and another in a few months properly when it warms up around here.
I bought the neutral buoyancy AL tank from ST, because cost was a factor. If cost is not a big factor for you, go steel for the additional capacity. You don't need to go to 130 cf. Go with a 100cf or so. Doubles are usually made from two 100cf, so a single one today can migrate to doubles in the future.

inventor
12-29-2009, 15:27
Most of the quarries I will be on are strip pits from coal mining. Most if not all are drive up by the water.


Off topic, but are you sure the pits are OK to dive? In WV it is anathema to get near 'mine water'. Part of the Kanawha River is off limits to swimmers, partly due to chemical plants, and partly due to mine runoff. This is the river in which anti-freeze was discovered. Yes, I said discovered in the river.:smiley11:

Just asking, I'm assuming you aren't the only one using these.:smiley20:

scubadiver888
12-29-2009, 15:41
bigman241! How is it going? Haven't seen you post in a while.

Both steel and aluminum can corrode. Some people have told me it happens more frequently with steel but this is rumour not fact.

Steel is stronger and therefore the walls on the tank can be thinner. This results in a lighter tank out of the water, assuming they are the same capacity.

Some shops will not fill an AL80 that is over 15 years old. Most have no problem filling a steel that is 40 years old. For some areas this doesn't apply at all.

You will need less weight with steel tanks as they start off more negatively buoyant in the water and remain negative/neutral.

Most divers prefer the buoyancy characteristics of steel tanks.

Initial cost of aluminum tanks is much less but if you believe the idea that steel lasts longer than aluminum, the amortized cost is about the same.

Some steel tanks are 8" diameters but boats have keepers for 7.25" diameters (standard AL80). You can get some sizes of steel with a 7.25" diameter so this is an issue with some tanks. The following steel tanks have an 8" diameter: LP95, AL100, LP104, HP119, LP120, HP130.

You can get steel tanks with an overfill rating (+) of 10%.

Some shops cannot fill tanks beyond 3000 PSI. This is only an issue for HP80 vs. AL80. An HP80 filled to 3000 PSI is less than 70 cu.ft. but an AL80 is 77 cu.ft. On the other hand, if you get HP100 and fill it to 3000 PSI you get 87 cu.ft. (10 cu.ft. more than an AL80).

Some steel tanks are shorter than the AL80. If you have long arms or are short, carrying an AL80 can be difficult. My instructor has to drag AL80s or carry one at a time because they are too long for her. The HP100 is shorter so she can pick it up by the valve and carry two at once. Additionally, the AL80 either hits her head or hits her legs. The shorter HP100 works much better for her torso length.

If you are going to get into cave diving or wreck penetration, an AL80 might not have enough air for safety. If I dive many of the wrecks in my area and do a penetration, I quickly find I require 60 cu.ft. of air just to do the dive. With an AL80 at 3000 PSI I'd be left with 17 cu.ft. of air. If something went wrong that is not enough air. On the other hand, with an HP100 at 3442 PSI would leave me with 40 cu.ft. of air for emergency situations.

Personally, I have decided to go with a steel tank. The biggest factors for me are (a) I'm going to be an instructor so I want to be sure I have plenty of air for various reasons (I'll be carrying too much weight sometimes, might have to buddy breathe an air hog, want to be first in the water and last out) and (b) I plan on diving a lot of wrecks at 80 feet or deeper. At some point I'm going to get into deco diving and trimix (many wrecks are well below 130 feet).

bigman241
12-29-2009, 15:52
First to inventor though off topic you make a very good point. Most of these pits are open to fishing infact there all in a state forest. Most if not all of them are open to swimming. In the last year or so there has been some discussion on whether or not there open to swimming or diving. One day the dnr says ok the next day no. For the most part there will be no issue. Heck last year when I got checked for my fishing license I was swimming in the same pit I will dive. The CO had no issue with it. Though the pit right down my house in a Fish and wildlife area is off limits sadly.

Scubadiver888 I was wondering how long it would take for someone to remember me. Been popping around for a few days. Where set to go to the keys the 8th of march for our cert. Dad and I are going and where going to rough it in a camp ground I see no reason to dump 150+ on a hotel room we will only sleep in. Our trip got put off in Oct because we sold a house on contract and the couple backed out leaving us with the house. It was go to Florida or install the much needed furnace. At least march will be close to spring so I will not be looking at diving gear for months before I can hit the local pits.
Hopefully I will not ask to many questions now and drive everyone nuts again. :smilie39:

scubadiver888
12-29-2009, 15:57
Ask away dude. I'm in training to be a DM right now. I'm sure I can use the practice answering questions. :smiley36:

bigman241
12-29-2009, 15:57
dam I was trying to avoid two post again. I do not see the tank length being a issue I am 6'5 don't think that will be a issue. Wreck diving and cave diving is a a big plan I have. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come. Plus I think with my weight I will be a air hog. Though that is a big reason why when I get paid Thursday my first stop will be the local gym and the treadmill and bikes.
Guess I should call the local shops and see if they fill up to the 3000+ Though even if they do not it will come in handy when I wreck dive.
Maybe you need to reread some of my post. not sure you know what your asking for when you say ask away.

bigman241! How is it going? Haven't seen you post in a while.

Both steel and aluminum can corrode. Some people have told me it happens more frequently with steel but this is rumour not fact.

Steel is stronger and therefore the walls on the tank can be thinner. This results in a lighter tank out of the water, assuming they are the same capacity.

Some shops will not fill an AL80 that is over 15 years old. Most have no problem filling a steel that is 40 years old. For some areas this doesn't apply at all.

You will need less weight with steel tanks as they start off more negatively buoyant in the water and remain negative/neutral.

Most divers prefer the buoyancy characteristics of steel tanks.

Initial cost of aluminum tanks is much less but if you believe the idea that steel lasts longer than aluminum, the amortized cost is about the same.

Some steel tanks are 8" diameters but boats have keepers for 7.25" diameters (standard AL80). You can get some sizes of steel with a 7.25" diameter so this is an issue with some tanks. The following steel tanks have an 8" diameter: LP95, AL100, LP104, HP119, LP120, HP130.

You can get steel tanks with an overfill rating (+) of 10%.

Some shops cannot fill tanks beyond 3000 PSI. This is only an issue for HP80 vs. AL80. An HP80 filled to 3000 PSI is less than 70 cu.ft. but an AL80 is 77 cu.ft. On the other hand, if you get HP100 and fill it to 3000 PSI you get 87 cu.ft. (10 cu.ft. more than an AL80).

Some steel tanks are shorter than the AL80. If you have long arms or are short, carrying an AL80 can be difficult. My instructor has to drag AL80s or carry one at a time because they are too long for her. The HP100 is shorter so she can pick it up by the valve and carry two at once. Additionally, the AL80 either hits her head or hits her legs. The shorter HP100 works much better for her torso length.

If you are going to get into cave diving or wreck penetration, an AL80 might not have enough air for safety. If I dive many of the wrecks in my area and do a penetration, I quickly find I require 60 cu.ft. of air just to do the dive. With an AL80 at 3000 PSI I'd be left with 17 cu.ft. of air. If something went wrong that is not enough air. On the other hand, with an HP100 at 3442 PSI would leave me with 40 cu.ft. of air for emergency situations.

Personally, I have decided to go with a steel tank. The biggest factors for me are (a) I'm going to be an instructor so I want to be sure I have plenty of air for various reasons (I'll be carrying too much weight sometimes, might have to buddy breathe an air hog, want to be first in the water and last out) and (b) I plan on diving a lot of wrecks at 80 feet or deeper. At some point I'm going to get into deco diving and trimix (many wrecks are well below 130 feet).

scubadiver888
12-29-2009, 16:22
dam I was trying to avoid two post again. I do not see the tank length being a issue I am 6'5 don't think that will be a issue.

Yeah, not a problem. I think my instructor is 5'4". I'm 6'0" and have no problems with AL80 tank lengths.



Wreck diving and cave diving is a a big plan I have. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come.

Focus on the next step and one day you'll be asking about wreck certification. Don't rush to get in a wreck. The more dives you have the more you'll enjoy wreck diving.



Plus I think with my weight I will be a air hog. Though that is a big reason why when I get paid Thursday my first stop will be the local gym and the treadmill and bikes.

Things are very different underwater. Your weight will be much less of an issue. New divers (all of them) are air hogs because they try to swim through the water. Learn to hover in one spot. Once you have mastered that, kick your fins to go forward. Breathe deeply and you will go up, deep exhale and you will go down. If you want to go up or down a lot (depends on how much wetsuit you are wearing and what depth you are currently at) you might need to add or subtract some air from your BCD/Wing. Most the time you weigh ZERO.

Being in shape is actually important for surface swims, getting your gear on, getting in the water (especially on a moving boat) and getting out of the water.



Guess I should call the local shops and see if they fill up to the 3000+ Though even if they do not it will come in handy when I wreck dive.

Ask them if they can fill to 3500 PSI. During a fill the cylinder will heat up. If you fill it to 3442 PSI, when it cools down you will have less. So most shops will have a compressor that fills to 3500 PSI. This way they can fill the 3442 a little hot to 3500 PSI and it will cool down to 3442 PSI (or there abouts).

There are tanks that hold 3500 PSI and one that even requires 4400 PSI. So some shops will be able to go well above 3442. My shop does AL80 and Worthington HP steel 99.999% of the time so our compressor will handle to 3500 PSI.



Maybe you need to reread some of my post. not sure you know what your asking for when you say ask away.


I remember. :smiley2:

P.S. if the shop fills too fast it will cool down a lot. I have seen tanks that read 3100 PSI hot and by the time I get to the dive site they are 2400 PSI. :(

comet24
12-29-2009, 16:28
Where set to go to the keys the 8th of march for our cert. Dad and I are going and where going to rough it in a camp ground I see no reason to dump 150+ on a hotel room we will only sleep in. Our trip got put off in Oct because we sold a house on contract and the couple backed out leaving us with the house. It was go to Florida or install the much needed furnace. At least march will be close to spring so I will not be looking at diving gear for months before I can hit the local pits.
Hopefully I will not ask to many questions now and drive everyone nuts again. :smilie39:

Camping in the Keys in January is great. Weather is perfect. Been a few years since I did the camping thing down there but it was a great time when I did.

mitsuguy
12-29-2009, 16:52
Might I make a suggestion? Buy whatever is easiest on your budget to keep you diving. Even if the dives are a little shorter, and you need to wear a little more lead.

In the end, it's quantity and quality of dives, not how you can eek every last second out of each one.

This way, you will learn to work on buoyancy and air consumption as well...

Also, should you go on vacation, chances are you will be stuck with AL80's as those are the choice over most of the world... Not a bad idea to be used to them...

Smashee
12-29-2009, 17:02
. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come. Plus I think with my weight I will be a air hog.

If you're looking at cave & wreck penetration by dives 20 to 40, I wouldn't bother buying tanks now. Rent 'em. If it turns out that you've got the innate skills to handle that sort of thing so quickly you might want to consider a CCR. Ask some of the guys on the RBW forums if you're interested in that sort of thing.

If you don't, then you'll (hopefully) have a few dives under your belt to be able to make a basic assessment of the sort of gear you'll need and the sort of time it's going to take to get you to where you want to be.

Vercingetorix
12-29-2009, 17:02
Concerning air quantity/pressure, the neutral AL80 is stamped that it can be pressurized to 3300 psi without over-pressurizing.

bigman241
12-29-2009, 17:10
I see no hurry to start cave diving or wreck diving. Sure I want to but I am not in a hurry to get there. Better off slow steady and safe then fast and dead.

. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come. Plus I think with my weight I will be a air hog.

If you're looking at cave & wreck penetration by dives 20 to 40, I wouldn't bother buying tanks now. Rent 'em. If it turns out that you've got the innate skills to handle that sort of thing so quickly you might want to consider a CCR. Ask some of the guys on the RBW forums if you're interested in that sort of thing.

If you don't, then you'll (hopefully) have a few dives under your belt to be able to make a basic assessment of the sort of gear you'll need and the sort of time it's going to take to get you to where you want to be.

in_cavediver
12-29-2009, 20:29
. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come. Plus I think with my weight I will be a air hog.

If you're looking at cave & wreck penetration by dives 20 to 40, I wouldn't bother buying tanks now. Rent 'em. If it turns out that you've got the innate skills to handle that sort of thing so quickly you might want to consider a CCR. Ask some of the guys on the RBW forums if you're interested in that sort of thing.

If you don't, then you'll (hopefully) have a few dives under your belt to be able to make a basic assessment of the sort of gear you'll need and the sort of time it's going to take to get you to where you want to be.

Tanks are cheap compared to a CCR. Lets see - $400-$800 vs $5k-$10k

My advice - go steel now. Also - look used. You likely could save 25%-50% off retail, especially if you have time on your side.

LP104/HP130 are great tanks as are the LP85/HP100's. If 8" isn't a problem, add in the LP95, LP108, and LP112's to the mix.

If cost becomes an issue - don't fret buying the Al80's. They can always become stage bottles later.

bigman241
12-30-2009, 04:51
CCR stands for closes circuit rebreather right.


. Every time I think of diving I think of rolling through a ship or cave. Of course that is not going to be at dive 5 but it will happen. Maybe dive 20 or 40 but it will come. Plus I think with my weight I will be a air hog.

If you're looking at cave & wreck penetration by dives 20 to 40, I wouldn't bother buying tanks now. Rent 'em. If it turns out that you've got the innate skills to handle that sort of thing so quickly you might want to consider a CCR. Ask some of the guys on the RBW forums if you're interested in that sort of thing.

If you don't, then you'll (hopefully) have a few dives under your belt to be able to make a basic assessment of the sort of gear you'll need and the sort of time it's going to take to get you to where you want to be.

Tanks are cheap compared to a CCR. Lets see - $400-$800 vs $5k-$10k

My advice - go steel now. Also - look used. You likely could save 25%-50% off retail, especially if you have time on your side.

LP104/HP130 are great tanks as are the LP85/HP100's. If 8" isn't a problem, add in the LP95, LP108, and LP112's to the mix.

If cost becomes an issue - don't fret buying the Al80's. They can always become stage bottles later.

Smashee
12-30-2009, 05:16
CCR stands for closes circuit rebreather right.

Closed Circuit Rebreather.

Not to be confused with the other CCR, more famous for classic rock songs like "Run Through The Jungle", "Proud Mary" and "Bad Moon Rising".

UCFKnightDiver
12-30-2009, 08:25
bigman241! How is it going? Haven't seen you post in a while.

Both steel and aluminum can corrode. Some people have told me it happens more frequently with steel but this is rumour not fact.


Huh? Aluminum is quite a bit more corrosion resistant that steel.

To what Vercingetorix said about buying one steel tank now and then getting another in a few years to double up, keep in mind it is best to match your steel tanks, so that one will not be longer than the other etc, as tanks can vary quite a bit from batch to batch, and even within a batch. With that being said, if you plan to go doubles at a later date I would get matched steel tanks.

scubadiver888
12-30-2009, 08:58
bigman241! How is it going? Haven't seen you post in a while.

Both steel and aluminum can corrode. Some people have told me it happens more frequently with steel but this is rumour not fact.


Huh? Aluminum is quite a bit more corrosion resistant that steel.


I have seen this posted a few times on forums like this. So I felt it was worth mentioning *BUT* I don't have any hard facts. I have not read any papers showing this to be true. I have not seen any studies.

I believe it to be true but I would bet money on it.

UCFKnightDiver
12-30-2009, 09:29
Steel scuba tanks are not stainless steel

bigman241
12-30-2009, 11:39
I am be wrong but from what I remember of my seadoo repair days and my welding class doesn't steel rust not corrode and aluminum corrodes so and does not rust. Guess it is all but the same thing. So I would thin your both right. I have seen what salt water does to an aluminum jetski engine. thought normally with a seadoo if it is a salt water boat you better have a air compressor and air tools and at least 25% of the steel bolts to replace bent and broken bolts Thats why when the shop we bought engines from told us having the case bolts was not a issue we would keep about half of them so we had a few of each.


bigman241! How is it going? Haven't seen you post in a while.

Both steel and aluminum can corrode. Some people have told me it happens more frequently with steel but this is rumour not fact.


Huh? Aluminum is quite a bit more corrosion resistant that steel.


I have seen this posted a few times on forums like this. So I felt it was worth mentioning *BUT* I don't have any hard facts. I have not read any papers showing this to be true. I have not seen any studies.

I believe it to be true but I would bet money on it.

scubadiver888
12-30-2009, 13:42
I am be wrong but from what I remember of my seadoo repair days and my welding class doesn't steel rust not corrode and aluminum corrodes so and does not rust. Guess it is all but the same thing. So I would thin your both right. I have seen what salt water does to an aluminum jetski engine. thought normally with a seadoo if it is a salt water boat you better have a air compressor and air tools and at least 25% of the steel bolts to replace bent and broken bolts Thats why when the shop we bought engines from told us having the case bolts was not a issue we would keep about half of them so we had a few of each.

I'm not sure what the difference between corrode and rust is. Everyone I have talked to believes if you don't clean your tanks, there is a higher change the steel tank will rust. One theory I have heard is that when steel starts to oxidize it just keeps rusting. When aluminum oxidizes, it creates a film of aluminum oxide and the aluminum underneath does not continue to oxidize. End result is, if not properly rinsed and stored, steel will oxidize faster than aluminum. This is why dive operators in the Caribbean use aluminum tanks.

UCFKnightDiver
12-30-2009, 14:15
Thats it, what scubadiver888 said, as to rust vs corrode, its essentially the same thing.

bigman241
12-30-2009, 14:53
I got this off of wiki
"In other words, corrosion is the wearing away of metals due to a chemical reaction.
Corrosion - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Corrosion)
Rust is a general term for a series of iron oxides (http://en.wikipedia.org/wiki/Iron_oxides), usually red oxides, formed by the reaction of iron (http://en.wikipedia.org/wiki/Iron) and oxygen (http://en.wikipedia.org/wiki/Oxygen) in the presence of water or air moisture
Rust - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Rust)"
Though there is technically a difference between rust and corrosion for what we are talking about the end result is the same. Seems to be rust is more of a iron issue. Since steel is made up of partly iron it is also a steel thing. But it is more like splitting hairs. Either way clean every piece of metal be it steel or aluminum or you’re going to be buying a new tank.
I was not trying to correct anyone more just trying to find the answer and figured I would share.




I am be wrong but from what I remember of my seadoo repair days and my welding class doesn't steel rust not corrode and aluminum corrodes so and does not rust. Guess it is all but the same thing. So I would thin your both right. I have seen what salt water does to an aluminum jetski engine. thought normally with a seadoo if it is a salt water boat you better have a air compressor and air tools and at least 25% of the steel bolts to replace bent and broken bolts Thats why when the shop we bought engines from told us having the case bolts was not a issue we would keep about half of them so we had a few of each.

I'm not sure what the difference between corrode and rust is. Everyone I have talked to believes if you don't clean your tanks, there is a higher change the steel tank will rust. One theory I have heard is that when steel starts to oxidize it just keeps rusting. When aluminum oxidizes, it creates a film of aluminum oxide and the aluminum underneath does not continue to oxidize. End result is, if not properly rinsed and stored, steel will oxidize faster than aluminum. This is why dive operators in the Caribbean use aluminum tanks.

RogerAg
12-30-2009, 16:16
You are still going to have to go 60 or 80 miles to that dive shop, even if you do buy the tanks.

That is unless you put your month over the tank valve and blow it up yourself.:smilie39:

bigman241
12-30-2009, 16:44
Still true. Though a point from another thread was if you rent a tank your talking a trip to get it and a trip back to return it. The the enxt time two trips. If I own one, two or more tanks I would make a trip fill them and then only make another when it is time to refill. Also If I have say two tanks figure that will do me two dives a week. I own a cabin on a lake 25 miles from the LDs but when I go to my cabin I drive almost right by it. SO fills would me easy. Normally I am at said cabin once a week even now in the dead of winter. This summer I will be spending alot of time over there so not to hard to get fills. Might do a few lake dives there for gear checks and task stuff such as getting my weight set but this lake is dark dirty and from what a fellow diver over there told me you can not see your hand right in front of your face. Though doing the task and gear checks there will be better then at home. The H.O.A it is in has a poll for members I was already given the ok to use it for checking my gear out and such. Plus my dad is on the board and happens to be in charge of the pool area so it is pretty much do as I wish just do not bother anyone important. :smiley20: Figure buy my own tanks when I go the the cabin I can hit the pool or lake to check stuff out or just get a quick dive in. Since I drive by the LDS each way fills going and coming will be easy. But if I rent I still have the issue of returning when I am diving at home. Plus I want the big tanks.
You are still going to have to go 60 or 80 miles to that dive shop, even if you do buy the tanks.

That is unless you put your month over the tank valve and blow it up yourself.:smilie39: