Are Old Tanks Worth Hydroing?

On Sep 13, 4:29 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:

> I was pretty specific about the conditions that would lead to scrapping the
> tank. It included significant flaking and pitting, either of which are
> likely to fail the tank on the next visual, with or without a hydro. Even if
> the tank might make it one more time, the cost benefit of tumbling a steel
> tank that old is limited and the risk of depending on such a tank for the
> five years until the next hydro date is higher than I'd choose to take.

It's my understanding that only aluminum tanks fail catastrophically,
and even then it usually fails when filling and is therefore more a
worry for the dive shop than the diver. If the tank passes the rigors
of a hydro test, it's pretty much guaranteed to withstand another 5
years of mere air fills. Tumbling only costs $15-20, a fraction of
the cost of a new steel tank. Even at $20, that's only $4 per year.
If you tumble and the tank fails hydro, you're out a lousy $20 at most
(plus the cost of the hydro). Risking a potential loss of $20 versus
having the use of a steel tank for the next 5 years at a prorated
additional cost of only $4 a year is definitely a risk I'd be willing
to take. Obviously we all have different risk thresholds.

On Sep 13, 4:29 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:

> I was pretty specific about the conditions that would lead to scrapping the
> tank. It included significant flaking and pitting, either of which are
> likely to fail the tank on the next visual, with or without a hydro. Even if
> the tank might make it one more time, the cost benefit of tumbling a steel
> tank that old is limited and the risk of depending on such a tank for the
> five years until the next hydro date is higher than I'd choose to take.

It's my understanding that only aluminum tanks fail catastrophically,
and even then it usually fails when filling and is therefore more a
worry for the dive shop than the diver. If the tank passes the rigors
of a hydro test, it's pretty much guaranteed to withstand another 5
years of mere air fills. Tumbling only costs $15-20, a fraction of
the cost of a new steel tank. Even at $20, that's only $4 per year.
If you tumble and the tank fails hydro, you're out a lousy $20 at most
(plus the cost of the hydro). Risking a potential loss of $20 versus
having the use of a steel tank for the next 5 years at a prorated
additional cost of only $4 a year is definitely a risk I'd be willing
to take. Obviously we all have different risk thresholds.

On Sep 13, 4:29 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:

> I was pretty specific about the conditions that would lead to scrapping the
> tank. It included significant flaking and pitting, either of which are
> likely to fail the tank on the next visual, with or without a hydro. Even if
> the tank might make it one more time, the cost benefit of tumbling a steel
> tank that old is limited and the risk of depending on such a tank for the
> five years until the next hydro date is higher than I'd choose to take.

It's my understanding that only aluminum tanks fail catastrophically,
and even then it usually fails when filling and is therefore more a
worry for the dive shop than the diver. If the tank passes the rigors
of a hydro test, it's pretty much guaranteed to withstand another 5
years of mere air fills. Tumbling only costs $15-20, a fraction of
the cost of a new steel tank. Even at $20, that's only $4 per year.
If you tumble and the tank fails hydro, you're out a lousy $20 at most
(plus the cost of the hydro). Risking a potential loss of $20 versus
having the use of a steel tank for the next 5 years at a prorated
additional cost of only $4 a year is definitely a risk I'd be willing
to take. Obviously we all have different risk thresholds.

Greg Mossman wrote:

> On Sep 13, 5:10 am, "Scott" <pugetsounddi...@gmail.com> wrote:
>
>>"Blah" <b...@hotmail.com> wrote in message
>>
>>news:5ksfcsF56dv3U1@mid.individual.net...
>>
>>
>>>Greg Mossman wrote:
>>>
>>>>On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>>>>- Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>>>>valve off and shine a small flashlight into the tank. If you see scales
>>
>>of
>>
>>>>>rust, pits or any similar indications that the inside of the tank is
>>>>>damaged, drill a hole in the tank and start over. There's no point in
>>
>>paying
>>
>>>>>good money to test a tank you already know won't pass. If it's smooth
>>>>>inside, have it hydro tested.
>>
>>>>What's wrong with getting it tumbled to remove the rust?
>>
>>>Everytime you do it reduces the wall thickness and reduces strength?
>>
>>Sure, you leave it run for a decade.
>
>
> Thanks. That's what I was wondering. After all, if the tank is
> tumbled to get rid of the rust, and it then passes hydro and a visual
> inspection, what's the worry? I think my local shop charged me $15 or
> $20 for a tumbling the last time, which wasn't much in the scheme of
> things after the tank passed hydro and earned me another 5 years of
> usage.
>
>
Tumbling gets rid of the dust, superficial scale, and cockroach eggs. If
the tank is actually pitted, you've got a permanent problem.

esg

Greg Mossman wrote:

> On Sep 13, 5:10 am, "Scott" <pugetsounddi...@gmail.com> wrote:
>
>>"Blah" <b...@hotmail.com> wrote in message
>>
>>news:5ksfcsF56dv3U1@mid.individual.net...
>>
>>
>>>Greg Mossman wrote:
>>>
>>>>On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>>>>- Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>>>>valve off and shine a small flashlight into the tank. If you see scales
>>
>>of
>>
>>>>>rust, pits or any similar indications that the inside of the tank is
>>>>>damaged, drill a hole in the tank and start over. There's no point in
>>
>>paying
>>
>>>>>good money to test a tank you already know won't pass. If it's smooth
>>>>>inside, have it hydro tested.
>>
>>>>What's wrong with getting it tumbled to remove the rust?
>>
>>>Everytime you do it reduces the wall thickness and reduces strength?
>>
>>Sure, you leave it run for a decade.
>
>
> Thanks. That's what I was wondering. After all, if the tank is
> tumbled to get rid of the rust, and it then passes hydro and a visual
> inspection, what's the worry? I think my local shop charged me $15 or
> $20 for a tumbling the last time, which wasn't much in the scheme of
> things after the tank passed hydro and earned me another 5 years of
> usage.
>
>
Tumbling gets rid of the dust, superficial scale, and cockroach eggs. If
the tank is actually pitted, you've got a permanent problem.

esg

Greg Mossman wrote:

> On Sep 13, 5:10 am, "Scott" <pugetsounddi...@gmail.com> wrote:
>
>>"Blah" <b...@hotmail.com> wrote in message
>>
>>news:5ksfcsF56dv3U1@mid.individual.net...
>>
>>
>>>Greg Mossman wrote:
>>>
>>>>On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>>>>- Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>>>>valve off and shine a small flashlight into the tank. If you see scales
>>
>>of
>>
>>>>>rust, pits or any similar indications that the inside of the tank is
>>>>>damaged, drill a hole in the tank and start over. There's no point in
>>
>>paying
>>
>>>>>good money to test a tank you already know won't pass. If it's smooth
>>>>>inside, have it hydro tested.
>>
>>>>What's wrong with getting it tumbled to remove the rust?
>>
>>>Everytime you do it reduces the wall thickness and reduces strength?
>>
>>Sure, you leave it run for a decade.
>
>
> Thanks. That's what I was wondering. After all, if the tank is
> tumbled to get rid of the rust, and it then passes hydro and a visual
> inspection, what's the worry? I think my local shop charged me $15 or
> $20 for a tumbling the last time, which wasn't much in the scheme of
> things after the tank passed hydro and earned me another 5 years of
> usage.
>
>
Tumbling gets rid of the dust, superficial scale, and cockroach eggs. If
the tank is actually pitted, you've got a permanent problem.

esg

Greg Mossman wrote:

> On Sep 13, 5:10 am, "Scott" <pugetsounddi...@gmail.com> wrote:
>
>>"Blah" <b...@hotmail.com> wrote in message
>>
>>news:5ksfcsF56dv3U1@mid.individual.net...
>>
>>
>>>Greg Mossman wrote:
>>>
>>>>On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>>>>- Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>>>>valve off and shine a small flashlight into the tank. If you see scales
>>
>>of
>>
>>>>>rust, pits or any similar indications that the inside of the tank is
>>>>>damaged, drill a hole in the tank and start over. There's no point in
>>
>>paying
>>
>>>>>good money to test a tank you already know won't pass. If it's smooth
>>>>>inside, have it hydro tested.
>>
>>>>What's wrong with getting it tumbled to remove the rust?
>>
>>>Everytime you do it reduces the wall thickness and reduces strength?
>>
>>Sure, you leave it run for a decade.
>
>
> Thanks. That's what I was wondering. After all, if the tank is
> tumbled to get rid of the rust, and it then passes hydro and a visual
> inspection, what's the worry? I think my local shop charged me $15 or
> $20 for a tumbling the last time, which wasn't much in the scheme of
> things after the tank passed hydro and earned me another 5 years of
> usage.
>
>
Tumbling gets rid of the dust, superficial scale, and cockroach eggs. If
the tank is actually pitted, you've got a permanent problem.

esg

Blah wrote:

> Greg Mossman wrote:
>
>> On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>> - Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>> valve off and shine a small flashlight into the tank. If you see
>>> scales of
>>> rust, pits or any similar indications that the inside of the tank is
>>> damaged, drill a hole in the tank and start over. There's no point in
>>> paying
>>> good money to test a tank you already know won't pass. If it's smooth
>>> inside, have it hydro tested.
>>
>>
>> What's wrong with getting it tumbled to remove the rust?
>>
> Everytime you do it reduces the wall thickness and reduces strength?

Not relevant.
There is a minimum wall thickness which can be measured with
an ultrasound thickness meter.
Matthias

Blah wrote:

> Greg Mossman wrote:
>
>> On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>> - Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>> valve off and shine a small flashlight into the tank. If you see
>>> scales of
>>> rust, pits or any similar indications that the inside of the tank is
>>> damaged, drill a hole in the tank and start over. There's no point in
>>> paying
>>> good money to test a tank you already know won't pass. If it's smooth
>>> inside, have it hydro tested.
>>
>>
>> What's wrong with getting it tumbled to remove the rust?
>>
> Everytime you do it reduces the wall thickness and reduces strength?

Not relevant.
There is a minimum wall thickness which can be measured with
an ultrasound thickness meter.
Matthias

Blah wrote:

> Greg Mossman wrote:
>
>> On Sep 12, 3:47 am, "Lee Bell" <pleeb...@bellsouth.net> wrote:
>>
>>> - Steel tanks tend to last longer, but are vulnerable to rust. Take the
>>> valve off and shine a small flashlight into the tank. If you see
>>> scales of
>>> rust, pits or any similar indications that the inside of the tank is
>>> damaged, drill a hole in the tank and start over. There's no point in
>>> paying
>>> good money to test a tank you already know won't pass. If it's smooth
>>> inside, have it hydro tested.
>>
>>
>> What's wrong with getting it tumbled to remove the rust?
>>
> Everytime you do it reduces the wall thickness and reduces strength?

Not relevant.
There is a minimum wall thickness which can be measured with
an ultrasound thickness meter.
Matthias