If you are talking about minor surface corrosion (inside or out), then yes. If its considerable then it depends on how bad the corrosion is. A VIP and hydro will give you the answer for sure.
New guy with a good question
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S
Scuba Diver 03
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hello. I'm sorry i can't help you
I'd hydro the tanks have them VIP'd and not worrry about it. With tanks of that vintage the inspector will have to do an eddy current test of the threads in the neck to detenct any cracks along with the hydro and the VIP. The odds of having a crack, particularly in a tank with relatively few cycles is pretty remote. The odds of missing an existing crack or having a crack that develops to the point of failure between VIP's is even remoter still.
A lot of people are way too worried that their scuba tank is going to explode the next time they fill it. A freind of mine does hydro tests for a living, testing thousands of O2 and scuba tanks per year and has only found a few scuba tanks that have failed due to fatigue cracks in the necks. The tanks in question require special eddy current testing every 18 months, which in practical terms means at the annual VIP, and this in itself serves to catch defective tanks before the problem gets critical. The biggest worry people should have is that enough improperly inspected tanks will fail that the DOT puts a life limit on the tanks and your perfectly good tanks end up condemned. Given that you paid $50 for 3 of them, you don't have much to worry about.
Of bigger concern are tanks that have been routinely pushed past their service limits. I have encountered a dive boat operator who fills his AL 80's to 4000 PSI to keep the customers happy. It's not only illegal, it's really really stupid. There are also some steel tanks out there that have been pushed over the limit (and I mean well over the 10% overfill allowed for the first 5 years) by a few tech divers. The life on these tanks is probably going to be shortened somewhat and they will potentially fail a hydro down the road - something a steel tank normally almost never does.
As for corrosion, in an aluminum tank the process is such that the coating that forms on the surface prevents further corrosion. So unlike rust, it is very much a self limiting process . Unless there was salt water standing in the tanks, they should be fine.
At times a tank may need to be tumbled with an abrasive cleaning solution inside it if the corrosion is fairly heavy. This is normally done in steel tanks to remove any thing other than flash rust to ensure a pit does not start to develop, but can also be done to a badly corroded aluminum tank to allow a better visual assessment of the problem and ensure there are no pits in the tank.
Tanks should be stored vertical as the bottom of the tank is the thickest portion of the tank and a small spot of corrosion there caused by a bit of standing moisture is easy to detect and less likely to cause as large a problem as it would on the relatively thin side wall of the tank.
A lot of people are way too worried that their scuba tank is going to explode the next time they fill it. A freind of mine does hydro tests for a living, testing thousands of O2 and scuba tanks per year and has only found a few scuba tanks that have failed due to fatigue cracks in the necks. The tanks in question require special eddy current testing every 18 months, which in practical terms means at the annual VIP, and this in itself serves to catch defective tanks before the problem gets critical. The biggest worry people should have is that enough improperly inspected tanks will fail that the DOT puts a life limit on the tanks and your perfectly good tanks end up condemned. Given that you paid $50 for 3 of them, you don't have much to worry about.
Of bigger concern are tanks that have been routinely pushed past their service limits. I have encountered a dive boat operator who fills his AL 80's to 4000 PSI to keep the customers happy. It's not only illegal, it's really really stupid. There are also some steel tanks out there that have been pushed over the limit (and I mean well over the 10% overfill allowed for the first 5 years) by a few tech divers. The life on these tanks is probably going to be shortened somewhat and they will potentially fail a hydro down the road - something a steel tank normally almost never does.
As for corrosion, in an aluminum tank the process is such that the coating that forms on the surface prevents further corrosion. So unlike rust, it is very much a self limiting process . Unless there was salt water standing in the tanks, they should be fine.
At times a tank may need to be tumbled with an abrasive cleaning solution inside it if the corrosion is fairly heavy. This is normally done in steel tanks to remove any thing other than flash rust to ensure a pit does not start to develop, but can also be done to a badly corroded aluminum tank to allow a better visual assessment of the problem and ensure there are no pits in the tank.
Tanks should be stored vertical as the bottom of the tank is the thickest portion of the tank and a small spot of corrosion there caused by a bit of standing moisture is easy to detect and less likely to cause as large a problem as it would on the relatively thin side wall of the tank.
OP
1Scubanewbie
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DA - Thanks for the post. I will do just that. The tanks look nearly unused on the outside. I'll have them hydro'd and see what they say.
You can also have them eddy current tested for cracks and such..
For sure, you know they have to be hydro'd. If you send them to hydro, they have to be VIP'd anyway....they do that there.
IF they come back failed, Luxfer will give you credit of some type based on how old the tank is...so that is also an option.
BTW...did these tanks come with valves?
For sure, you know they have to be hydro'd. If you send them to hydro, they have to be VIP'd anyway....they do that there.
IF they come back failed, Luxfer will give you credit of some type based on how old the tank is...so that is also an option.
BTW...did these tanks come with valves?
OP
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Yes these tanks came with US Diver's valves. They are yellow, US Divers, Luxfer Aluminum tanks. One looks as though it were never used. The other two look as though they've seen a dozen or so dives. Minor abrasions to the paint...nothing more. I've just been introduced to this wonderful sport and purchased these because I knew the relative cost of one on Ebay. I've heard a lot about "tech" divers. What exactly is a "techie"? I've been trying to find diving information on the net. My local Dive shop dissed the Rodales site as something he would never rely on. My wife insists that we could probably go to Mexico and get certified almost as cheap as we can do it here. My local Dive shop in Colorado charges $349 to do your open water dives in a lake that's as clear as mud. Any thoughts?
Stone
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Many people do the class and pool work at home, then do their open water dives at a nice location. It would be a shame to spend a lot of time reading and attending class while at a resort.
A VIP is required as part of the hydro testing process. The test facility has a ton of books with the required procedures and exemptions for the various tanks out there. This measn that Eddy current testing will be done if required as part of the VIP.
Where it gets misconstrued is a lot of local dive shops send your tank out for hydro and then do a VIP and stick their inspection sticker on it when it returns. They are basically ripping you off on the price of thier redundant VIP. .
Also a VIP every year, unlike the one at hydro is not a legal requirement but rather an industry practice. This means a shop would not neccesarily have to inspect their rental tanks in between hydros. Good industry practice means a credible dive shop won't fill a tank without a VIP in the last 12 months, but some shops get sloppy with their own tanks.
I recently purchased 4 tanks from a dive shop who's owner was retiring. One of them was so bad it failed a VIP due to a rather large pit in the bottom of the tank due to water in the tank. The shop owner was not concerned, he had another dive shop who he was sure would buy it. Scary.
You can do your pool work locally and then get a referral to do the open water dives somewhere nice. This costs around $50 to $75 extra but is available through most training agencies.
Loosely speaking a technical diver is one who dives caves or wrecks and is normally diving in overhead environments and often if not usually is well outside the normal depth limits and normal no-decompression limits. It involves an attitude and outlook on both technique and on equipment and it gets really confusing from there.
They come in several flavors from the minimalist hogarthian type tech divers to those who do not believe that taking one more piece of equipment along that may fail is a bad thing, and to those non standard technical divers who take a more personal and individual approach to thinking out gear configurations and techniques.
This makes for interesting reading as two technical divers from different schools of thought can argue at great lenght about the finer points of something as simple as rigging a stage bottle.
If you want to get into technical diving a lot of it will come down to the philospohy of the instructor and of the people you dive with. Some instructors are pretty open minded and encourage you to make rational and intelligent decisions about your gear configuration and teach the pros and cons of various configurations. Others do the pretty much the same thing but with a strong bias and basically insist the rational choice is to do it their way.
Being a bit of a non-conformist and prefering to rationalize my personal gear configuration based on my particular diving requirements I fall into the non standard group. Actually it was this non conformity that got me into doing what is considerd technical diving before it was called that. But while I'm not totally sold on all of what is included with "doing it right", I would do it that way and configure my gear that way if the rest of the people I dove with dove that way. It's sort of a social contract for conformity if you want to dive with that group.
In my opinion, it's nice to get a wide variety of perspectives on things and I really don't believe that any one group knows it all. Unfortunately there are some out there who believe in the one true way who expect blind acceptance to their teachings and who will ridicule anyone who seeks improvement or sees it differently. They probably don't like me much either.
Where it gets misconstrued is a lot of local dive shops send your tank out for hydro and then do a VIP and stick their inspection sticker on it when it returns. They are basically ripping you off on the price of thier redundant VIP. .
Also a VIP every year, unlike the one at hydro is not a legal requirement but rather an industry practice. This means a shop would not neccesarily have to inspect their rental tanks in between hydros. Good industry practice means a credible dive shop won't fill a tank without a VIP in the last 12 months, but some shops get sloppy with their own tanks.
I recently purchased 4 tanks from a dive shop who's owner was retiring. One of them was so bad it failed a VIP due to a rather large pit in the bottom of the tank due to water in the tank. The shop owner was not concerned, he had another dive shop who he was sure would buy it. Scary.
You can do your pool work locally and then get a referral to do the open water dives somewhere nice. This costs around $50 to $75 extra but is available through most training agencies.
Loosely speaking a technical diver is one who dives caves or wrecks and is normally diving in overhead environments and often if not usually is well outside the normal depth limits and normal no-decompression limits. It involves an attitude and outlook on both technique and on equipment and it gets really confusing from there.
They come in several flavors from the minimalist hogarthian type tech divers to those who do not believe that taking one more piece of equipment along that may fail is a bad thing, and to those non standard technical divers who take a more personal and individual approach to thinking out gear configurations and techniques.
This makes for interesting reading as two technical divers from different schools of thought can argue at great lenght about the finer points of something as simple as rigging a stage bottle.
If you want to get into technical diving a lot of it will come down to the philospohy of the instructor and of the people you dive with. Some instructors are pretty open minded and encourage you to make rational and intelligent decisions about your gear configuration and teach the pros and cons of various configurations. Others do the pretty much the same thing but with a strong bias and basically insist the rational choice is to do it their way.
Being a bit of a non-conformist and prefering to rationalize my personal gear configuration based on my particular diving requirements I fall into the non standard group. Actually it was this non conformity that got me into doing what is considerd technical diving before it was called that. But while I'm not totally sold on all of what is included with "doing it right", I would do it that way and configure my gear that way if the rest of the people I dove with dove that way. It's sort of a social contract for conformity if you want to dive with that group.
In my opinion, it's nice to get a wide variety of perspectives on things and I really don't believe that any one group knows it all. Unfortunately there are some out there who believe in the one true way who expect blind acceptance to their teachings and who will ridicule anyone who seeks improvement or sees it differently. They probably don't like me much either.
OP
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Techies are called "snowboarders" in Colorado Live on the edge...die young!!! Anyway, I appreciate the info. I guess there are conformity rules in every sport. Anyone today who has a batting stance like Pete Rose is told how to correct their problem. I'm sure I'll find my style as I grow out of the newbie stage. The first stage is Unconscience incompetence. ...ie you don't know how much you don't know. The next is conscience incompetence....you discover how much you really don't know. Followed a long while later by conscience competence where careful concentration leads to competence. You know you've arrived when you reach unconscience competence...ie...you could do it in your sleep.=-)
Live on the edge...die young!!! Anyway, I appreciate the info. I guess there are conformity rules in every sport. Anyone today who has a batting stance like Pete Rose is told how to correct their problem. I'm sure I'll find my style as I grow out of the newbie stage. The first stage is Unconscience incompetence. ...ie you don't know how much you don't know. The next is conscience incompetence....you discover how much you really don't know. Followed a long while later by conscience competence where careful concentration leads to competence. You know you've arrived when you reach unconscience competence...ie...you could do it in your sleep.=-)Similar threads
