T6351 aluminum was used for scuba tanks from the 1970s thru the 1980s. New tanks are made from 6061 aluminum. Watch and find out what happens to 6351 tanks and why nobody wants to fill them.
Great video. I'm from Canada where a have and use 2 oilless 4 stage compressors to fill my tanks. I never agreed with hydro testing on aluminum takes as to steel tanks. Aluminum does not like to be stretched. The crack or start a crack soon after Steel will flex many many times before distributing its molecular structure. I visual my own tanks 2 times a years and ultrasound then every two years. The ultrasound is done a a lab by experienced techs using calibration blocks as a comparison. Having said that, I do own a wk tank and a older Luxfer. I've never had issues with these tanks but, after watching your video, common sense tells be to follow your advice and retire those tanks. Thank you
Neck cracks can be dangerous, years ago I was working in a shop with a water tank for wet fills, one of these tanks cracked on fill and air was busting thought the neck. Thank goodness it didn't fully blow, there was 3 of us standing next to the fill station. Thanks for the comment.
Absolutely! Glad you agree. Thanks for watching. Stay tuned I have many more videos to come, in the middle of summer madness with little time to spare.
Nice job ,the video, straight to the points. should have stopped by when I passed in 2019,2020 on my trips to Key west, will next time, regards Anders Hansen Classdiving Sierra Leone
GUESS WHAT ? just two weeks ago .... a dive shop owner freaked out when I brought my three old tanks from 1979 in for visuals and I knew two needed Hydro . He was almost in tears telling me they were dangerous and they CAN"T be inspected or filled ...So I took them to another shop and they said - we know that dive shops in Florida refuse to service the older tanks BUT...YES they would service and fill them !
I'm not surprised by the shop owner's reaction, as per DOT we can still inspect, test and fill along with visual eddy test. However in Florida we've had multiple tanks rupture and seen first hand the consequence of neck cracks. It's up to the individual shop to make that decision. Thanks for the comment.
I had a 10.4 litre 232 Bar Alloy 6061 tank (85 c.f.) fail a visual for a crack in the neck - DO NOT think that new alloys are not susceptible to load cracking, IF you leave a scuba tank full long enough it will fail at the weakest point. I now only dive steel cylinders which are looked after better than my dive computer, and IF I'm not planning to dive for 3 months or more, I leave them at 50 Bar (500 psi) so as not to put unnecessary stress on the cylinder.
Sometimes a fold in the neck can be mistaken for SLC neck crack. I've seen many shops confuse folds with SLC in 6061. I'm not saying that it can't happen but the chances are slim, an eddy current test will confirm a SLC.
thank you, thank you -You just saved my Lux 13 that I bought from Brownie's Third Lung in 90 and still has the original air in it - I was about to trash it - never used in 32 years - I was wanting to use it as a pony with a Blu3 Nemo I just picked up for metal detecting off the beach - but I just started draining a Lux 50 I have left from 86 - it has been sitting in the Garage since last hydro I think in 04 when I was going to start diving again but work and work travel got in the way - I do have a Catalina 80 I bought last year so I do have something I can use if I want to go deeper than the 9ft of the Nemo -
I glad to hear my info was helpful to you. Having a pony bottle in addition to third lung is a great idea, I'm a big advocate for carrying a pony bottle. Beach metal detecting is also in my interest, I use a Garrett Sea Hunter with a graphite handle. The lightweight handle allows me to work the beach for hours. When the nor'easter storms start to roll in and remove a lot of sand is my favorite time to metal detect the beaches. Haven't used a BluNemo yet, but hope to someday. Thanks commenting and watching my channel!
This is great information for the scuba diving community, however, are you absolutely, 100% sure that there’s never been in that crack on a 6061 aluminum cylinder? Thank you!
Great information! I just placed a bid on eBay for one for $55.00...Its the exact same yellow tank with a date stamp of 3-79. 😕 I’m hoping to be outbid.
I think tanks from back in the '50s were made of steel. I grew up with tanks my dad had, still charged. For decades!! I can imagine modern tanks charged and left charged for extended times (years, decades) might develop and grow cracks under pressure. Perhaps crack growth or even initiation would decrease with tanks being stored near empty?
yes tanks from the 50s thru the 60s were made of steel. Aluminum tanks were introduced early 70s somewhere around 1972-73. Never good idea to have tanks full to max pressure for extended time.
Thanks,I know nothing.lol. I came across 8 tanks last filled in the 90s.took them to a local dive shop.The old school diver told me about the tests and basically gave me scrap prices for them,I think.I have no knowledge about diving but watching your video I hope they are not used.Some of them were still full.I made 200$ plus a t shirt I think because he wanted them not to be used.Could I be right or did I get ripped off? Not ripped off because I got them for free.Just wanna know what anyone thinks.Very thankful :)
If you got money for old 6351 tanks you did good, they are only worth scape prices. The last time a went to recycle tanks I got .54 cents a pound, of course that price fluctuates. You did better than I did, he might have some other plans like yard art or just shop collection. Whenever I get one with confirmed neck crack I keep it for teaching purpose, that could another reason he wanted them. Thanks for watching!
I picked up 2 tanks that are filled from a junk removal job … they are sitting in my driveway … and the recyclers won’t take them full. Im scared shitless of these things but I want to get them out of here. They aren’t that old probably 90s or so … I’m going to pick them up off the ground and put them in my shed. Im worried of them exploding.. but I know it’s extremely rare.
Check the born on date, if from 1990s or newer the risk is low. You can empty the air slowly and then they’re nothing more than aluminum container. I recycle condemned tanks, also the valve are yellow brass… more value then aluminum.
@@scubatechkeylargo got them emptied … one had ALOT of air the other almost nothing. I can handle them safely now … and I owe it all to you. Thanks for the confidence booster … they were from mid 90s
One has to wonder,if when the valves are reinstalled that they may be over tightened causing stress on the threads. Was never mentioned what the valves were torqued to.
I used to work at Florida Keys Dive Center, Tavernier (just south of Key Largo). One day a seasoned dive boat captain walked in to my counter and bought something. I asked him how he got his peg leg. He told me he lost it when filling a bad tank that exploded.
@@scubatechkeylargo I lived in Tavernier around 2004-2005. I was there the year the FKDC bought their big boat, and the Boy Scout camp (Sea Camp?) would book trips on it. I lived through the 8 hurricanes that hit the Keys those 2 years (evacuated for Wilma).
@@scubatechkeylargo Did your shops have to cancel many trips those years? FKDC had to cancel trips, hurricane after hurricane. It was sad. Especially after booking the new big boat.
The year of all those hurricanes was tuff on the diving business, weather is a big factor on the success of a dive business, which continues to be unreliable.
Yes, Catalina only uses 6061. Some shops might not know this or they just have a standard "no fill "policy about tanks from the 1980's, which we can't control. Thanks for question.
Question: I had my old US Diver tank hydro'ed a couple of years ago and the person who tested my tank scraped not only all the old inspection stickers off of it, they scraped the Aqua-Lung/US Diver and the Professional chevrons off of it. Does everyone does that? OK I bought the tank in 85 so would be one of the tanks you are talking about?
Removing old decals is recommended to avoid corrosion from developing underneath. As far as the original decal, if corrosion is present then it's understandable. I question more the testing of 1985 tanks and keeping it in service. To be legal test it must have a eddy current test along with hydro, then stamped with "VE" next to hydro date.
Luxfer started the change over as early 1987 thru 1988. 80,s 100’s 63’s etc had different change dates. Medical (oxygen ) tanks also had their change dates. They completed the transfer to 6061 by early 1989.
Yes, they can. Years ago when the cracks started appearing I witnessed a crack leaking thru the exterior. When this happens the tank is near rupture and extreme caution must be taken.
Local shop won't touch a cylinder made before 2000. Also, all aluminum cylinders should get scrapped at the 15-20 year mark. Especially those used in salt water. Even 6061 will crack after awhile.
Some have exploded and separated into pieces and unfortunately some have had fatal injuries. I personally know two people injured on two separate incidents, fortunately both survived the bast. The most recent incidents, one in Canada and the other in Utilla.
If they see a crack then I would just believe them and get a new cylinder. And no not necessarily from them. A 200 bar explosion can cost you your life. As a diver you're literally carrying a bomb on your back. Don't mess with that stuff.
Great explanation of the aluminum tank issue. Thanks for posting!
Thanks for the comment!
Angel is the best, he's done top notch work on everything scuba for years. And he's just a great guy.
Thanks for the comment!
Great video. I'm from Canada where a have and use 2 oilless 4 stage compressors to fill my tanks. I never agreed with hydro testing on aluminum takes as to steel tanks. Aluminum does not like to be stretched. The crack or start a crack soon after
Steel will flex many many times before distributing its molecular structure. I visual my own tanks 2 times a years and ultrasound then every two years. The ultrasound is done a a lab by experienced techs using calibration blocks as a comparison. Having said that, I do own a wk tank and a older Luxfer. I've never had issues with these tanks but, after watching your video, common sense tells be to follow your advice and retire those tanks. Thank you
Neck cracks can be dangerous, years ago I was working in a shop with a water tank for wet fills, one of these tanks cracked on fill and air was busting thought the neck. Thank goodness it didn't fully blow, there was 3 of us standing next to the fill station. Thanks for the comment.
Good explanation and visual demo of the issue. Totally agree. It’s time for these to be recycled ♻️ into something much safer 👍
Absolutely! Glad you agree. Thanks for watching. Stay tuned I have many more videos to come, in the middle of summer madness with little time to spare.
Most excellent presentation! Thanks much for this great info.
Glad you enjoyed it!
Nice job ,the video, straight to the points. should have stopped by when I passed in 2019,2020 on my trips to Key west, will next time, regards Anders Hansen Classdiving Sierra Leone
Thanks, please do stop in your next trip to the Florida Keys.
GUESS WHAT ? just two weeks ago .... a dive shop owner freaked out when I brought my three old tanks from 1979 in for visuals and I knew two needed Hydro . He was almost in tears telling me they were dangerous and they CAN"T be inspected or filled ...So I took them to another shop and they said - we know that dive shops in Florida refuse to service the older tanks BUT...YES they would service and fill them !
I'm not surprised by the shop owner's reaction, as per DOT we can still inspect, test and fill along with visual eddy test. However in Florida we've had multiple tanks rupture and seen first hand the consequence of neck cracks. It's up to the individual shop to make that decision. Thanks for the comment.
I had a 10.4 litre 232 Bar Alloy 6061 tank (85 c.f.) fail a visual for a crack in the neck - DO NOT think that new alloys are not susceptible to load cracking, IF you leave a scuba tank full long enough it will fail at the weakest point. I now only dive steel cylinders which are looked after better than my dive computer, and IF I'm not planning to dive for 3 months or more, I leave them at 50 Bar (500 psi) so as not to put unnecessary stress on the cylinder.
Sometimes a fold in the neck can be mistaken for SLC neck crack. I've seen many shops confuse folds with SLC in 6061.
I'm not saying that it can't happen but the chances are slim, an eddy current test will confirm a SLC.
100% correct.
Glad to see you agree. Thanks for watching
thank you, thank you -You just saved my Lux 13 that I bought from Brownie's Third Lung in 90 and still has the original air in it - I was about to trash it - never used in 32 years - I was wanting to use it as a pony with a Blu3 Nemo I just picked up for metal detecting off the beach - but I just started draining a Lux 50 I have left from 86 - it has been sitting in the Garage since last hydro I think in 04 when I was going to start diving again but work and work travel got in the way - I do have a Catalina 80 I bought last year so I do have something I can use if I want to go deeper than the 9ft of the Nemo
-
I glad to hear my info was helpful to you. Having a pony bottle in addition to third lung is a great idea, I'm a big advocate for carrying a pony bottle. Beach metal detecting is also in my interest, I use a Garrett Sea Hunter with a graphite handle. The lightweight handle allows me to work the beach for hours. When the nor'easter storms start to roll in and remove a lot of sand is my favorite time to metal detect the beaches.
Haven't used a BluNemo yet, but hope to someday. Thanks commenting and watching my channel!
Filled and never used in 32 years? I’m not sure I understand why anyone would ever do that.
This is great information for the scuba diving community, however, are you absolutely, 100% sure that there’s never been in that crack on a 6061 aluminum cylinder? Thank you!
Great information!
I just placed a bid on eBay for one for $55.00...Its the exact same yellow tank with a date stamp of 3-79. 😕
I’m hoping to be outbid.
6351 tanks from the 1970's are very likely to have a neck crack, in my opinion they're only good for yard art...LOL
@@scubatechkeylargo
Unfortunately, yes. Thankfully I was outbid by $1.00 and I'm walking away from that one.
By new, by new, by new, you never know how its been handled so many years
Very interesting
Glad you think so!
I think tanks from back in the '50s were made of steel.
I grew up with tanks my dad had, still charged.
For decades!!
I can imagine modern tanks charged and left charged for extended times (years, decades) might develop and grow cracks under pressure.
Perhaps crack growth or even initiation would decrease with tanks being stored near empty?
yes tanks from the 50s thru the 60s were made of steel. Aluminum tanks were introduced early 70s somewhere around 1972-73. Never good idea to have tanks full to max pressure for extended time.
Thanx.
You're welcome!
Thanks,I know nothing.lol.
I came across 8 tanks last filled in the 90s.took them to a local dive shop.The old school diver told me about the tests and basically gave me scrap prices for them,I think.I have no knowledge about diving but watching your video I hope they are not used.Some of them were still full.I made 200$ plus a t shirt I think because he wanted them not to be used.Could I be right or did I get ripped off? Not ripped off because I got them for free.Just wanna know what anyone thinks.Very thankful :)
If you got money for old 6351 tanks you did good, they are only worth scape prices. The last time a went to recycle tanks I got .54 cents a pound, of course that price fluctuates. You did better than I did, he might have some other plans like yard art or just shop collection. Whenever I get one with confirmed neck crack I keep it for teaching purpose, that could another reason he wanted them. Thanks for watching!
For a few hundred bucks it’s worth saving your life.
I picked up 2 tanks that are filled from a junk removal job … they are sitting in my driveway … and the recyclers won’t take them full. Im scared shitless of these things but I want to get them out of here. They aren’t that old probably 90s or so … I’m going to pick them up off the ground and put them in my shed. Im worried of them exploding.. but I know it’s extremely rare.
Check the born on date, if from 1990s or newer the risk is low.
You can empty the air slowly and then they’re nothing more than aluminum container. I recycle condemned tanks, also the valve are yellow brass… more value then aluminum.
@@scubatechkeylargo thanks for the quick reply … I will check them
@@scubatechkeylargo got them emptied … one had ALOT of air the other almost nothing. I can handle them safely now … and I owe it all to you. Thanks for the confidence booster … they were from mid 90s
@@TrollHunterxXx glad to hear it worked out. Thanks for watching my channel!
CGA doesn't make law. They create standards. CFR49 then refer to those standards.
Walter Kidde, not Kiddie. Good video
Good catch, thanks for the correction
One has to wonder,if when the valves are reinstalled that they may be over tightened causing stress on the threads. Was never mentioned what the valves were torqued to.
The prescribed torqued for valves is 50 to 60 ft.lbs
not much at all.
I used to work at Florida Keys Dive Center, Tavernier (just south of Key Largo). One day a seasoned dive boat captain walked in to my counter and bought something. I asked him how he got his peg leg. He told me he lost it when filling a bad tank that exploded.
wow a exploded tanks can do that. I been doing hydros for Flakys for about 10 years. Tom and Pam sold the shop not long ago IDC now owns Flakys.
@@scubatechkeylargo I lived in Tavernier around 2004-2005. I was there the year the FKDC bought their big boat, and the Boy Scout camp (Sea Camp?) would book trips on it. I lived through the 8 hurricanes that hit the Keys those 2 years (evacuated for Wilma).
I remember those years, I was still in the Miami area working local dive shops unit I made the move the Keys in 2012.
@@scubatechkeylargo Did your shops have to cancel many trips those years? FKDC had to cancel trips, hurricane after hurricane. It was sad. Especially after booking the new big boat.
The year of all those hurricanes was tuff on the diving business, weather is a big factor on the success of a dive business, which continues to be unreliable.
Confused about the Catalina tank. All Catalina tanks are made of 6061, why do dive shops still refuse to service early year models?
Yes, Catalina only uses 6061. Some shops might not know this or they just have a standard "no fill "policy about tanks from the 1980's, which we can't control. Thanks for question.
Locally, the shops won't touch any before 2000! Luxfer made some bad ones into the 90's that they refuse to acknowledge.
Question: I had my old US Diver tank hydro'ed a couple of years ago and the person who tested my tank scraped not only all the old inspection stickers off of it, they scraped the Aqua-Lung/US Diver and the Professional chevrons off of it. Does everyone does that? OK I bought the tank in 85 so would be one of the tanks you are talking about?
Removing old decals is recommended to avoid corrosion from developing underneath. As far as the original decal, if corrosion is present then it's understandable. I question more the testing of 1985 tanks and keeping it in service. To be legal test it must have a eddy current test along with hydro, then stamped with "VE" next to hydro date.
I took mine to a recycling center
That's the best place for them.
Huh I thought after 6/1988 they were swapped over 6061
Luxfer started the change over as early 1987 thru 1988. 80,s 100’s 63’s etc had different change dates. Medical (oxygen ) tanks also had their change dates. They completed the transfer to 6061 by early 1989.
Cracked neck doesnt leak?
Yes, they can. Years ago when the cracks started appearing I witnessed a crack leaking thru the exterior. When this happens the tank is near rupture and extreme caution must be taken.
@@scubatechkeylargo thank you. Very educational
Local shop won't touch a cylinder made before 2000. Also, all aluminum cylinders should get scrapped at the 15-20 year mark. Especially those used in salt water. Even 6061 will crack after awhile.
Every shop has it’s own internal rules about 6351, can’t argue with the more conservative.
So why is my dive shopper refusing to fill
Each shop will have their own policy, there's no law that obligates the service or filling of 6351 cylinders.
So they crack but do they explode?
Yes, they can! There's been 3-4 catastrophic failures that have destroyed dive shops ect.
Some have exploded and separated into pieces and unfortunately some have had fatal injuries. I personally know two people injured on two separate incidents, fortunately both survived the bast. The most recent incidents, one in Canada and the other in Utilla.
On the up side, you can make a real nice ashtray outta that old tank for your smoker friends.
Good ol' 6351 ! Not! 💩👎
Wind chimes are cool too! Pony bottles work best!
A common repurpose is to cut the bottom off make a hanging bell and many local artist paint a reef scene on them.
They wat you to buy new tanks...from them.
That's always possible, however these tanks do have a high chance of developing cracks which I don't want near my legs when filling.
If they see a crack then I would just believe them and get a new cylinder. And no not necessarily from them. A 200 bar explosion can cost you your life. As a diver you're literally carrying a bomb on your back. Don't mess with that stuff.
I do Not like Aluminum Tanks ... PERIOD !!!
Steel is my choice of dive tanks, however keeping newer aluminum up to date with inspections & hydro testing makes aluminum a safe option.