Should I buy these used tanks? Weren't used for diving.

[Glock Diver]

Question for those more knowledgeable about tanks:
I have a non-diver friend who has 2 SCUBA tanks that he used for paintball, to refill his paintball gun. Tanks have never been in the water. He always used air in the tanks, obtained from a LDS or from a friend with a compressor. (I thought all paintball guns used CO₂, but what do I know?) He would take the 2 filled tanks out to the field where they played, and refilled their guns from these tanks.

He's no longer into paintball and will sell me the 2 tanks together for $75.

I did see a picture of them, and they appear to be in good shape, of course I'll do a visual lookover before purchasing. They are stamped with the following:

M4002 06C02 CATALINA S80 TC-3AL M207

Visual decal is dated January 2003.


My 3 questions, as I've always been a renter of tanks:
1. What does the stamp indicate about the cylinders?
2. Should I be concerned that it was used for non-breathing air? I'm sure a hydro and a vis inspection will assure me of it's structural integrity, but what about cleanliness?
3. Would you buy these 2 tanks for $75?

thanks in advance!

 

[Rhone Man]

I read that as stating that they are Aluminium 80 cu ft tanks, with an initial hydro date of 2007 and not redone since then. However, I am a bit perplexed how they could have a visual inspection dated of 2003.

I wouldn't be too worried about the fact it hasn't been used for non-breathing air. Drain it down. Get a visual. Fill it with filtered air from a dive shop and you will be fine.

$75 for two Aluminium 80s with 3 years left to go on hydro is officially a steal. Bite the guy's hand off.

 

[deepstops]

I think the original hydro was 06 02 (hence the 01 03 viz sticker).

$75 for the pair is a smoking deal (even if they need a hydro and viz). Grab them or send me his number

 

[bleeb]

He always used air in the tanks, obtained from a LDS or from a friend with a compressor.

2. Should I be concerned that it was used for non-breathing air? I'm sure a hydro and a vis inspection will assure me of it's structural integrity, but what about cleanliness?

If he's been getting them filled by a non-diving friend with a compressor, there's a chance that there may be some lubricant oil in the tank. If it were me, I'd take them into a knowledgeable LDS and make sure they were cleaned at the same time as any inspections (and maybe the valves too, if you're using the same ones). It's a fairly standard procedure, especially for places that provide nitrox (by partial pressure mixing).

Anyone with more knowledge about what non-breathable crud can come out of a non-breathing air compressor willing to comment further on exactly how much risk we're really talking about here?

 

[NorthWoodsDiver]

M4002 is the manufacture's number. It means little to you since the manufacture's name is also printed on the tank.

The next set of numbers is the first hydro test and born on date. 06 of 2002. The "C" in the middle is the hydro tester symbol/Independent inspector symbol.

Of course the word Catalina is the manufacture. This company never used that "bad" alloy 6351 and the companies that did stopped by 1991 so no worries there.

S80 stands for "super 80" or 80 ft^3 but actually your tank has a volume of 77ft^3 at 3000psi at 70 degrees (F).

"TC" stands for Transport Canada which is an acceptable alternative to a DOT or ICC stamping in the USA.

"3AL" means the tank is made of aluminum and was manufactured seamlessly.

"M207" is probably the most recent hydro stamp though I'm not totally sure on that.

These tanks should be fine for use in Scuba as they were designed for Scuba use. If you plan to dive with EANx or pure O2 then special precautions need to be taken but if your diving air then get them visually inspected and filled. If 07 is the most recent hydro then dont worry about getting a hydro done.

Hope that helps

 

[Glock Diver]

Thanks all, this is a big help!

I did find some info on Catalina's website that says the "M207" indicates metric 207 bars, which is equivalent to 3000psi.

So if manufactured in 6/2002, it should just need another hydro and a visual, correct? Divers Direct charges $35 for a hydro and viz. Added to the $75 price he wants, that would be $145 for 2 used AL80's, which isn't too bad.

If I want to use the tanks for Nitrox also, does anyone know what additional charges the dive shop may charge me?

 

[bleeb]

"M207" is probably the most recent hydro stamp though I'm not totally sure on that.

Thought the "207" was the service pressure in bar. Not sure about the "M".

...

Ok, had to look it up. The "M" is actually part of the "3ALM" code, which refers to the Transport Canada spec.

BTW, there should be another line of data stamped on the tanks, above the one the OP provided, that includes things like each tank's unique serial number.

 

[deepstops]

Thanks all, this is a big help!

I did find some info on Catalina's website that says the "M207" indicates metric 207 bars, which is equivalent to 3000psi.

So if manufactured in 6/2002, it should just need another hydro and a visual, correct? Divers Direct charges $35 for a hydro and viz. Added to the $75 price he wants, that would be $145 for 2 used AL80's, which isn't too bad.

If I want to use the tanks for Nitrox also, does anyone know what additional charges the dive shop may charge me?

If they do partial pressure nitrox fills (where pure O2 s being used with a top-off of air), they'll need to be cleaned for oxygen service. I find prices for O2 cleaning vary a lot from $25 to $80 so shop around for someone that will give the best price on the combined service.

 

[NorthWoodsDiver]

Thanks all, this is a big help!

I did find some info on Catalina's website that says the "M207" indicates metric 207 bars, which is equivalent to 3000psi.

So if manufactured in 6/2002, it should just need another hydro and a visual, correct? Divers Direct charges $35 for a hydro and viz. Added to the $75 price he wants, that would be $145 for 2 used AL80's, which isn't too bad.

If I want to use the tanks for Nitrox also, does anyone know what additional charges the dive shop may charge me?

I figured a pressure needed to be on there someplace, I never thought about it being BAR instead of PSI. Thought the TC should have clued me in. Learn something new everyday I guess.

Anyway for nitrox fills, best practice is to have them O2 cleaned and if it was me I would get 200bar DIN/K valves if you dont already have them. Scubatoys sells a thermo provalve already serviced for O2 for like $40 which is easier then cleaning the valve yourself. Cleaning the tank is a simple task because its aluminum. Though if there is grease all over the threads its a PITA to get off.

Oxygen cleaning is a service that many dive shops provide. cost is anywhere from $10-50 a tank and it can be done at home also with some basic tools and time. Oxygen Hackers guide is a major help here.

With all that said my experience has been that if a tank didn't come to me serviced for O2 then its an air tank and I will buy one already designated for O2 or nitrox. When Mike is selling the new hymarks with a new hydro for like $150ish and they are ready for 100% oxygen its hard to beat once you start adding up costs.

So for me it would be $75 for the tanks, 25 for a hydro/vis each, $40 for new valves each, O2 clean for about $1 worth of crystal simple green or Dawn. Thats a combined cost of about $210ish so thats a savings of about $100 for me but I hate O2 cleaning tanks so its worth buying new if you can afford it...

It never hurts to own separate tanks for air and nitrox anyway.

 

[james croft]

If you are sure the tanks were filled by a compressor at a LDS I would have them inspected and dive them.