View Full Version : what to watch when buying old tanks.

03-19-2010, 20:22
One of the local paw shops said he had some scuba gear in the back he would drag out for me. I am planning on checking in in a week or so with him and had a question.
He said he had about everything including a few tanks.

What should I look for when buying used properly old tanks that have been siting for some time?
Not sure if their steel or alum. I would guess alum 80s. I figured rust on the out side if their steel, hydro, vis dates mostly both outdated. Then maybe check the air pressure with my reg or one of the ones he has. If no pressure then maybe remove he valve and check the inside. Or am I over thinking it?

If their our dated on vis and/or hydro and look ok what would alum 80s be worth? Both to high ranges and what brands should I avoid. I know their is a max age for them so what is the current cut off.

03-19-2010, 20:31
I wouldn't really buy it from the pawn shop seriously. It is best to actually get it from a scuba shop. If you're looking for Aluminum 80s, they're not expensive and some dive shops offer free shipping for it too.

As for the pawn shop, they will not remove the valves for you, nor inspect the tank for you, and not hydro and viz it for you.

03-19-2010, 21:16
Lets start of with aluminum tanks. Don't buy anything with an original hydro date before 1990. Luxfer had problems with the old alloy they used up to around 1988 or so.
Steel tanks last alot longer than aluminum tanks. If steel look for the manufacturer and the pressure rating and original hydro. There are many types of steel cylinders and many pressure ratings 2250, 2400, 3180, 3442, 3500 psi rated. ( I would avoid PST steel tanks )
For any cylinder
1- look at condition of cylinder painted or galvanized, or natural finish.
2- look at the shape of cylinder. roll on floor without the boot on it to see if it is round, no bows bumps, or dents.
3- look for dings on the cylinder.
4- look inside the cylinder for any problems. Rust, pitting, crap, small animals , Jimmy Hoffa's remains ( bring a flashlight )
5- look for cracks in the threads on the cylinder.
These are a few of the things you should do before you purchase a used cylinder.

Most likely you will need a hydro test and for sure a vis and fill. The hydro could cost between $15.00 to $40.00 depending on the area. A vis and fill could be in the $10.00 to $25.00 range. You need to add these costs on to the cost of the cylinder to give you a true cost of the used cylinder vs. a new cylinder that would come with a current hydro and Vis and fill.

There are some really great finds out there, but there are alot of land mines out there also.

Hope this helps,
Jim Breslin

03-20-2010, 01:22
I figured they would not check it for me figured I would check it. Not that I am looking for alum 80 in fact steel 130s. Just figured it would be what he had. Being he had had it all for some time and knows nothing about diving I am hoping for a good deal

03-20-2010, 06:10

I doubt that he will have 130's.
Most likely they are going to be al80's. I would offer him $50.00 if they were 80's in good condition. Everybody has to have an al80, in their dive kit. Al 80's are good for short dives, shallow dives, pool dives, or just for filling car tires or air tools.
Jim Breslin

03-20-2010, 06:24
Lets start of with aluminum tanks. Don't buy anything with an original hydro date before 1990. Luxfer had problems with the old alloy they used up to around 1988 or so.

This is important. Many shops will not fill these tanks due to the questionable alloy issues.


03-20-2010, 07:00

I am the king of the craigslist scrounge. My most recent scores were 80lbs of lead scuba weights for less than scrap lead price that included a heavy milk crate like carton and several weight belts and $30 tank.

That said, I would recommend that in your specific case you look at taking the plunge and buying a new tank in the size you want. Given the amount of wt you are needing, and your current SAC rate, you will benefit from a big steel tank on two levels. Less lead and longer dives. I don't normally recommend that new divers take the plunge and buy tanks but just like my recommendation to you on the wet suit, I think you are a unique case here.

That said, I would also take up INCAVEs offer to try out some of his stable of tanks first. You never really know until you try something.

For example, I have an LP121 that I had no intention of buying until I rented it. The shop said I was the only diver who had ever liked the thing and I got it for a song. It trims out great for me and I end up perfectly weighted with no lead when I use it. I am looking for another one as well.

03-20-2010, 07:30
You can sometimes find good buys if you are a frequent user of the scuba forums. I pickup up two Worthington X-7 HP Steel 120's, one year old, including new visual and fill for $275 each. Close enough for me to pick up so no shipping. These are $390 plus shipping new.

03-20-2010, 10:20
My reasoning for the alum 80 is what jbres1 one said and dad was using them and had 1000 psi or so when we came up with me using a steel 120.

On a side not how in the heck can you use a air tool on a scuba tank.

03-21-2010, 10:28
Since this is your thread its not a hijack.
You take a first stage reg and plug all ports except (1) high pressue port and (1) low pressure port. You install a button gauge in the high pressure port, and a quick disconnect hose with QD by 1/4npt on the other. Add an air fitting to the 1/4" end of the fitting and have at it.. You now have an 80 cu ft storage bottle to use on an air tool.
you can buy the fitting here.

Adapters and Special Fittings - Dive Gear Express (http://www.divegearexpress.com/regulators/adapters.shtml)
Adapter: 1/4-Inch NPT Male = BC Inflator QD

I also have the tire inflator kit that I have used .

Note: you will need to be able to adjust the air pressure output on the first stage down to less than 100 psig +/-.

Jim Breslin

03-21-2010, 12:38
Why not see if the pawn shop is willing to let you take them over to your LDS and have them looked at to see:

1) if they're even worth messing with,

2) what they're worth, and

3) how much it would cost to bring them current.

03-22-2010, 07:55
find out what a hydor will cost you localy, and add that in to the price of a takn out of date, or close to it.
here it is $70 for hydro.