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ColdPass
02-21-2008, 15:01
I searched, but didn't come across a buyer's guide for checking out used steel tanks.

I don't even have pictures or the size at the moment, but have an aquaintance wanting to sell some "old" and "big" steel scuba tanks.

What are the chances that old steel tanks are still servicable? Do they have a typical life span?

Should I take off the valves and look for pitting inside? They'll need new inspections anyway.

Thoughts?

UCFKnightDiver
02-21-2008, 15:35
well if you want to send me two for free I could tell you :) if they dont pass hydro or vis you could always scrap them and get some money. Sorry though I dont know alot but if I had to guess as long as they arnt rusted, they have a good chance of passing hydro, is there still any air in them? if there is then that is even better because if there is air in them its harder for water to seep in.

doczerothree
02-21-2008, 15:48
check for current vip and hydro. it would be nice if the tanks you are thinking of buying are current. (hydro very 5 years and vip every year). check the valves for discoloration and the knob for any play. I know of no "users guide to used tanks" look for dings and pock marks on the metal. when it doubt pass.


SEMPER DEEP

MSilvia
02-21-2008, 16:05
The service life of steel tanks is excellent. I have a couple of steel LP72s I got used for $75 for the pair. They have an original hydro date from the 1960s, hadn't been inspected in the 10 years they sat in someone's garage with a few hundred psi in each of them, and they passed hydro and vis with flying colors. I've been using them without issue for 6 years now.

ColdPass
02-21-2008, 16:16
Thanks, folks. I'll check them out this weekend. Hopefully they're in good shape. I'm glad to hear they have a good long service life. I was reading in some of the posts about aluminum tanks where some of the shops won't fill tanks older than 15 years.

CompuDude
02-21-2008, 16:22
Steel tanks can easily last for 30 years, or more, or they can be condemned in barely one year, if poorly treated/maintained.

I always insist on a current, recent inspection at an LDS before buying, ditto for Hydro if it needs it. Make the sale contingent on passing inspection.

Hydro is only one every 5 years, so if it passed hydro a year ago and only needs a vis inspection (VIP sticker), you're probably safe to buy. If hydro has expired or will soon, I would, again, make the sale contingent on passing inspection. Unless, of course, you're getting such a good deal that you're ok with the loss if it fails.

BSea
02-21-2008, 16:27
I have several steel 72's also. I recently bought 2 for $100 total with a hydro of 11/06, and all they needed was a current VIP. So there are some deals out there.

One thing you should probably avoid are the tanks with 1/2 valves. Not because they are bad, but because I've run into some places that won't fill them. Most valves made after the early 60's will have the 3/4 valves, so the smaller necks are getting pretty rare.

terrillja
02-21-2008, 17:08
Thanks, folks. I'll check them out this weekend. Hopefully they're in good shape. I'm glad to hear they have a good long service life. I was reading in some of the posts about aluminum tanks where some of the shops won't fill tanks older than 15 years.

That has more to do with the alloy that was used more than how the tank was treated. The only thing the age has to do with anything is that it's been a while since they used those alloys. If someone had wanted to sell me a 1884 Luxfer in 1992, I would have passed back then too.

Having said that some shops have a blanket 15 year policy on all AL tanks, including Catalina, which was never shown to suffer from SLC. My advice when buying used is along w/ what compudude said, make the sale contingent on passing vis/hrdro, as well as making sure shops in your area will fill the cylinders. A simple call will tell you their fill policy.

cummings66
02-21-2008, 18:37
I've never seen a dive shop anywhere have a seconds hesitation in filling a steel cylinder, Aluminum cylinders on the other hand get the third degree on a regular basis.

I don't know the rules for certain on steel tanks, but I'd think in this case it sounds like it's out of vis and maybe hydro. Get a vis first, no sense paying for a hydro if the thing won't pass vis.

terrillja
02-21-2008, 18:41
I've never seen a dive shop anywhere have a seconds hesitation in filling a steel cylinder, Aluminum cylinders on the other hand get the third degree on a regular basis.

I don't know the rules for certain on steel tanks, but I'd think in this case it sounds like it's out of vis and maybe hydro. Get a vis first, no sense paying for a hydro if the thing won't pass vis.
Good thought- if it needs to be tumbled a lot it would probably have to be rehydroed. Better to get the inside checked out first.

mentalmarine
02-22-2008, 10:35
Anyone know of any good deals out there for a steel tank? Ive been looking all over, or have a suggestion where I could look?
Thanks
Landen

terrillja
02-22-2008, 11:13
Anyone know of any good deals out there for a steel tank? Ive been looking all over, or have a suggestion where I could look?
Thanks
Landen
Watch cragislist, there are occasional deals there

mike_s
02-22-2008, 11:34
Anyone know of any good deals out there for a steel tank? Ive been looking all over, or have a suggestion where I could look?
Thanks
Landen


Not sure if you want new or used.

used, check craigslist and the forums classified.


New? Worthington has the market corned and they never put their tanks on sale. Every now and then you'll see a LDS knock a few bucks off, but they fall under XSSCUBA's MAP price guidelines, so they are all pretty much the same advertised price no matter where you go.

Also worthingtons distribution method (ship one tank at a time each when ordered and dealers dont' stock much) works for direct shipments from the factory to customer when bought and cuts down volume LDS purchases.

Faber is pretty much their only competition. Divers Direct puts their HP100's on sale several times a year for $249 each. They are typcially last years hydro though, but for the savings, not that big of a deal.

terrillja
02-22-2008, 11:45
Anyone know of any good deals out there for a steel tank? Ive been looking all over, or have a suggestion where I could look?
Thanks
Landen


Not sure if you want new or used.

used, check craigslist and the forums classified.


New? Worthington has the market corned and they never put their tanks on sale. Every now and then you'll see a LDS knock a few bucks off, but they fall under XSSCUBA's MAP price guidelines, so they are all pretty much the same advertised price no matter where you go.

Also worthingtons distribution method (ship one tank at a time each when ordered and dealers dont' stock much) works for direct shipments from the factory to customer when bought and cuts down volume LDS purchases.

Faber is pretty much their only competition. Divers Direct puts their HP100's on sale several times a year for $249 each. They are typcially last years hydro though, but for the savings, not that big of a deal.
I picked up some HP80s from DD earlier this year with a 07/2007 hydro. Nothing against ST, but I prefer the look of the fabers more.

CompuDude
02-22-2008, 12:01
For fresh water, Fabers are great. For salt water, I vastly prefer the anti-rust characteristics of Worthington's (and PST's) hot dip galvanized tanks over Faber's pretty white paint job... which can chip with normal use.

I own both (couldn't resist that Faber sale), but still very much prefer the Worthingtons. Better valves, too. Thermo Pro valves kick the pants off the SoS valves.

mentalmarine
02-22-2008, 12:07
I remember that sale, I should have picked one up then. I am on craigslist right now looking for one. I would be diving fresh most of the time, so a faber would be a good option.

ColdPass
02-23-2008, 13:07
Well, to follow up on my original question, I went to check out the two tanks in question. The ad described "two large steel tanks" so I had hopes that they would be steel 120s at "$100 each or both for $170."

However, they turned out to be older aluminum 80s. They were both Luxfer from the early 90s, but were both out of hydro and visual. Apparently the father of the fellow selling them had been filling them at the firestation, so "hydro wasn't required."

Anyway, I passed, since buying aluminum tanks out of hydro seems to be a risky proposition. Even if I bought them at the scrap value of $40 each, by the time I had them visually and hydrostatically tested, I'd have about $80 in each of them. For that price I can buy some that are current on inspections off of e-bay and not risk having them fail inspections before I even got to use them once.

So I'm still looking. Maybe I'll go support my LDS and buy there.

CompuDude
02-23-2008, 14:51
Always ask those questions from the seller before wasting the time and gas to go see. I can't tell you how many uneducated tank sellers there are out there.

It's possible to do well buying used tanks, though. I'm selling a couple that I originally bought used. It's not worth it to ship used steel tanks, though, so generally you want to find something local, and sometimes you just have to wait a while for the right tank to pop up.

boates
02-23-2008, 20:58
Why bother...our gear is the cheapest part of the cost of diving

terrillja
02-23-2008, 21:04
Why bother...our gear is the cheapest part of the cost of diving

I'd tend to disagree, with air fills at $4 each, shore dives are cheap. Maybe if you do tons of trips and charters the gear would seem cheap, but the % of $$ I have spent on gear is much greater than the amount spent using it.

cummings66
02-24-2008, 07:52
I wish i could agree that the gear is cheap, but I can't. Look at what my 24 Watt HID cannistor light costs, or the double steel HP120's, or the drysuit, etc. For those items alone you could take a good dive trip someplace and they're only the start.

skdvr
02-24-2008, 17:03
I wish i could agree that the gear is cheap, but I can't. Look at what my 24 Watt HID cannistor light costs, or the double steel HP120's, or the drysuit, etc. For those items alone you could take a good dive trip someplace and they're only the start.

I agree. In the past month alone I have dropped a few grand in new tanks and drysuit and then all the stuff you have to buy with a drysuit like new fins, boots, undergarments. Gear is not cheap by any means...

Phil

CompuDude
02-24-2008, 18:11
I wish i could agree that the gear is cheap, but I can't. Look at what my 24 Watt HID cannistor light costs, or the double steel HP120's, or the drysuit, etc. For those items alone you could take a good dive trip someplace and they're only the start.

I agree. In the past month alone I have dropped a few grand in new tanks and drysuit and then all the stuff you have to buy with a drysuit like new fins, boots, undergarments. Gear is not cheap by any means...

Phil

I spent well over $10k on gear in 2007.

I'm soooo screwed if my wife ever sees this post...

ChrisA
02-24-2008, 18:13
What are the chances that old steel tanks are still servicable? Do they have a typical life span?

Steel tanks CAN last forever. I have one made in 1968. On the other hand some steel tanks fail their first hydro. What kills steel tanks is water. If you get water in a tank it can rust. Ideally the yearly VIP will catch this and the inspector will make you tumble the tank to remove the rust. But if the tank sits for years with water inside the rust can seriously eat away at the wall thickness to the point where the tank fails hydro.

There are also people who will overfill their tanks by as much as 50%. This gives you some extra air but pretty much destroys the tank if you do it enough times.

The Local dive shop here opened in the 1950's and I think they still have a few tanks almost that old in their rental inventory. Steel 72's can last forever

Should you look at them? Maybe. But do you know how to tell a small problem that can be easily fixed by tumbling from a fatal problem that means the tank needs to be condemned? It is easy to see if the tank is very good or very, very bad but the grey areas need some one with experience. Take it to a scuba shop and get a VIP.

Even if it looks very good I would have any used tank inspected and maybe even hydro'd if I did not know it's history. A tank that looks nice may still have been grossly overfilled, you will only know with a hydro test. But on the other hand if you know the diver selling you the tank and he knows the history of the tank you are likely fine.

in_cavediver
02-24-2008, 20:15
I wish i could agree that the gear is cheap, but I can't. Look at what my 24 Watt HID cannistor light costs, or the double steel HP120's, or the drysuit, etc. For those items alone you could take a good dive trip someplace and they're only the start.

I agree. In the past month alone I have dropped a few grand in new tanks and drysuit and then all the stuff you have to buy with a drysuit like new fins, boots, undergarments. Gear is not cheap by any means...

Phil

I spent well over $10k on gear in 2007.

I'm soooo screwed if my wife ever sees this post...

I at least don't have to worry about that - she a tec/cave diver too. My problem is its pairs or qauds of everything. Otherwise its "Thanks honey - how did you know I wanted a scooter?" or "Thanks honey - I needed another set of regs for XXX"

Now - what does 4 steel tanks and 4 regs cost these days........

mentalmarine
03-27-2008, 13:36
I picked up a OMS LP121 from ebay for about 200. Had it vis'd last week and its good to go. Now I am on the prowl for a backplate and harness, as I found a used oxycheq wing for a good price.

Crimediver
03-27-2008, 19:54
I dive steel tanks older than me and I am 52.

Any rust free steel tank is a good deal assuming it passes hydro. No worries about sustained load cracking that is a factor in Luxfer Al 6351 alloy. A tank stored with air keeps out moisure. it should have a bell like tone when struck on the side. Some steel tanks may have a bit of rust in them that can be tumbled out. A tank with current hydro is a good sign. I would stay clear of tanks owned or coming from cave country as they may have been overpressurized. I check the burst disc. Some folks double up on the burst discs and crank the pressure past the rating for that tank. Tanks with 2 discs are suspect as far as I'm concerned. Stay away from vinyl coated steel tanks as they can be problematic in doing visuals. Any galvanized tank with air in it is probably OK. Remove valve and take a peek if practical. There is more but these tips generally will help buy a good tank.

navyhmc
03-27-2008, 20:56
I picked up a OMS LP121 from ebay for about 200. Had it vis'd last week and its good to go. Now I am on the prowl for a backplate and harness, as I found a used oxycheq wing for a good price.

The only problem with buying used tanks on line is you don't know for sure what you're getting.

Case in point: I saw a couple of LP 108's on ebay with starting price of $50 each. Good price, right? Well it turns out that the seller had been using these for cave diving and had been overfilling them for his dives-had been filling then to 3442 psi to get the most air into the tanks. While I have total faith in steel, what kind of life expectancy decrease can you expect when a tank is filled to 1.3 times the certified pressure. Yes, I know that when a tank is hydro'd it is going to 5/3 the working pressure, but that is once every 5 years. What type of stress is this doing to the steel? I have noted that some cave divers will use a tank for 1-2 years, sell it off and get new ones partially due to overfilling.

Others have noted a lot of tanks on ebay are 6351 alloy-not highly desirable in the diving world.

UCFKnightDiver
03-28-2008, 20:30
I was lead to believe by several cave divers that the LP Steel tanks and the HP steel tanks had steel with the same thickness, the only difference was that the hp tanks were acctually tested to those higher pressures so I dont see the risk in over filling them at all and by these accounts should pass hydro just like hp steel tanks....

If I am wrong someone set me straight

So if this is right which I think it is....lp steel tanks should not inheritantly fail hydro more than hp tanks would but rather I would think the opposite because the hydro on the lp would be at a lower pressure than the hp and the hp would be filled to that high pressure mark every time

in_cavediver
03-29-2008, 06:16
I was lead to believe by several cave divers that the LP Steel tanks and the HP steel tanks had steel with the same thickness, the only difference was that the hp tanks were acctually tested to those higher pressures so I dont see the risk in over filling them at all and by these accounts should pass hydro just like hp steel tanks....

If I am wrong someone set me straight

So if this is right which I think it is....lp steel tanks should not inheritantly fail hydro more than hp tanks would but rather I would think the opposite because the hydro on the lp would be at a lower pressure than the hp and the hp would be filled to that high pressure mark every time

You are partially right. There isn't a significant difference in thickness between LP and HP tanks, but the alloy is not the same. The HP tanks have a higher tensile strength alloy.

Now, translated to diving - Cave filling LP tanks does shorten the life of the LP tank. The question is by how much and do we care? A typical 3AA steel tank used in the gas industry can last well over 50 years. The oldest I have seen had a hydro in the 1920's. Total fills can be in 10's to 100's of thousands. If we say we get 10% of the life, we are still talking about 1-10 thousand fills. A lot for the life of a scuba tank.

Now for hydro failures. I have a few LP cave treated sets of doubles. Both have had thier first hydro and not failed. Speaking with cave divers in Florida, its uncommon for an LP steel tank to fail hydro. On the other hand, the older PST HP tanks (3500) seem to fail more. I know of two locally and I believe Compudude had 2 fail as well. Its quite possible the higher tensile strength alloy used can develop fatigue which leads to hydro fail.

Lastly, remember the DOT mandates leak before fail and the burst pressures on the tanks above are WELL above the fill pressures discussed. (If I recall from a engineering test report I saw, the average burst pressure on my PST 104 was around 12,500 psi)

mentalmarine
03-29-2008, 19:27
I picked up a OMS LP121 from ebay for about 200. Had it vis'd last week and its good to go. Now I am on the prowl for a backplate and harness, as I found a used oxycheq wing for a good price.

The only problem with buying used tanks on line is you don't know for sure what you're getting.

Case in point: I saw a couple of LP 108's on ebay with starting price of $50 each. Good price, right? Well it turns out that the seller had been using these for cave diving and had been overfilling them for his dives-had been filling then to 3442 psi to get the most air into the tanks. While I have total faith in steel, what kind of life expectancy decrease can you expect when a tank is filled to 1.3 times the certified pressure. Yes, I know that when a tank is hydro'd it is going to 5/3 the working pressure, but that is once every 5 years. What type of stress is this doing to the steel? I have noted that some cave divers will use a tank for 1-2 years, sell it off and get new ones partially due to overfilling.

Others have noted a lot of tanks on ebay are 6351 alloy-not highly desirable in the diving world.

I have heard a lot of the same issues as well. I spoke with this particular seller about these issues and felt confident that I was getting a good deal. There seem to be a lot of tanks on ebay that I wouldnt go near, there are also good deals to be had as well.

cummings66
03-29-2008, 20:31
Lots of things on Ebay that way, you've got to do your homework and hope the seller is honest.

Tanks are one of those hard to judge areas. I saw a lawsuit over a Ebay scuba tank on I think Peoples Court where he got it and it failed vis. The seller seemed to say, sorry, tough luck. The judge made the seller make good on it.

That was several years back.

AMASKU8200
04-02-2008, 00:48
All The Tanks I Have Are Used. I Have Two Al80s From The Early 70's And To Older Lp Steels I Guess I Was Lucky They All Passed Hydro And All Had Air In Them When I Purchased Them.