Short answer: rent tanks.

Longer answer, depending on the manufacturer, most shops now will not
fill tanks older than 1988 because of cracking problems with an alloy
commonly used then. Several tanks have exploded during fills. The odds
may be small, but you do not want to be in the room with an exploding
tank.

If you're not diving a lot, you're better off renting tanks. Even if
you get tanks cheap, you will still have to get them inspected
annually and hydroed every five years. You could rent a lot of tanks
before you pay as much as $100 plus the annual service costs.

Another question your post raises is how long has it been since you
dived? You might want to consider a refresher course if it's been as
long as your question implies.

Sounds like either you or your shop got the story a bit wrong. As George
already stated, there's a whole series of tanks made prior to 1988 out of a
different aluminum alloy. Both Walter Kidde and Luxfer used it. Catalina
never did. The problem is not so much the cracking that George mentioned,
thought that's part of the problem, it's what happens when the tanks fail.
Unlike other alloys and steel tanks, these tanks fail explosively. Instead
of simply splitting and dumping all their gas, they fragment. A few people
have died and more have been severely injured.

Slowly but surely, the shops that will fill pre 1988 Luxfer and Kidde tanks
are disappearing. A friend recently purchased a regluator and BCD along with
two of these tanks. When he asked about getting them inspected, his wife and
I conspired to buy him new ones for Christmas. I, personally, drilled holes
in both the tanks he bought and took them over to the recycle center. I
suggest you do the same with yours or, if you prefer, take the shop up on
the discount offer. It's up to you.

As for renting versus owning, you're going to have to make up your own mind.
I dive from my own boats or from shore often enough to want my own tanks. I
also prefer the buoyancy characteristics of the tanks I use to those of a
standard 80 aluminum tank. For me, the choice is easy, I own my own tanks
and use them even on local operators that include tanks in the cost of the
charter. If you dive less often and can generally rent tanks somewhere for
all the diving you do, renting may very well be the best option. When
comparing cost, don't forget to factor in the cost of gas fills for your
tanks. The price for rentals normally includes the cost of the gas in them.

Lee

See . http://hazmat.dot.gov/pubs/reports/cylinder/3al_advisory.pdf for
the tanks in question. For scuba applications, cylinders that have
been inspected by the "Visual Plus" method are still acceptable,
although many shops now refuse to fill them. If you ask around, you
should be able to get them filled if they are in hydro and have had
the "visual Plus" eddy current inspection.

I got 50$ for mine. But its too late now.
http://www.luxfercylinders.com/support/bulletins/20040204.shtml

gary

If you only dive a few times a year with these tanks you would be better off
renting. Owning tanks is the way to go for most divers that dive frequently,
but that's for convenience. When you own your own tanks you need to have
them inspected every year and they have to have a hydro every five years.
It's not worth the expense for several dives a year.

Al
Bottoms Up Divers

If you only dive a few times a year with these tanks you would be better off
renting. Owning tanks is the way to go for most divers that dive frequently,
but that's for convenience. When you own your own tanks you need to have
them inspected every year and they have to have a hydro every five years.
It's not worth the expense for several dives a year.

Al
Bottoms Up Divers

<snip>

Depending upon the number and types of dives that you do per year, it
*can* be cheaper to rent than to own... There is a certain convenience
factor that is involved with having a set of tanks available for spur of
the moment dives though... It would be easy for you to create yourself a
spreadsheet for the costs that you might experience locally... You will
need to know the following:

A1.  Cost of a rental tank
A2.  Cost of get a personal tank filled
A3.  Cost to get a personal tank inspected (per year)
A4.  Cost to get a personal tank hydroed
A5.  Years that a hydro is good for (5)
A6.  Dives you expect to do per year
A7.  Initial cost to purchase a tank
A8.  Projected lifespan of a tank

You will calculate the following:
A10.  Cost to rent
A11.  Cost to own tanks

For my first test, I set the following assumptions:
A1=8
A2=5
A3=10
A4=20
A5=5
A6=5
A7=100
A8=30

A10 = A6 * A1
A11 = A6*A2 + A3 + A7/A8 + A4/A5

This resulted in it being more expensive to own your own tanks than to
rent when you are doing 5 dives per year and your costs match the
assumptions for the various values that I entered above... This is close
enough that you might want to still consider owning your own tanks just
for the convenience factor... It's nice not having to rush back to the LDS
to return a tank at the end of the day... It's nice having a filled tank
ready for whenever you need it instead of having to go to the shop to get
one... Create a spreadsheet, plug in your numbers and see what makes sense
to you in your particular situation...