scuba tank used for on board air - anyone done it?

[rflud]

I have a large scuba tank that I was thinking of using for on board air. It seems that with a the right regulator this shouldn't be a problem. A scuba tank will hold air at about 3000-3500 PSI (or more). Any thoughts?

 

[76 Explorerette]

you dive? or ya just have a tank?

 

[rflud]

I just got into diving. Just by chance I saw a couple of tanks at a yard sale today and I figured I would pick it up and see if I could use it for the CO2 air. I don't want to shell out the $$$$ for a power tank. I've read several posts on other news groups and many people have reservations but I haven't seen any real reason why it won't work. I don't want to do anything that is unsafe though.

 

[Steve]

I saw a couple of tanks at a yard sale today and I figured I would pick it up and see if I could use it for the CO2 air.

So are you asking about using a SCUBA tank for air or CO2? If air, it's legal but it won't fill many tires. If for CO2, it's not legal and you probably won't find anyone who will fill a SCUBA tank with CO2.

 

[SaddleUp]

There are several posts discussing ways to do a CO2 tank on the cheap. If you can't find an old CO2 bottle cheap (Hint: Some Fire Extinguishers use CO2) then you can still buy a CO2 tank for about $100. Add anywhere from $30 up to $120 depending upon what regulator and you have the same basic thing as a power tank. The lower price is a static preset regulator and the higher is a good quality guage set where the pressure is adjustable. If you want to adjust the pressure then don't go cheap. CO2 will freeze up the cheap guages.

 

[Madgyver]

You need to change the valve on it to a CGA 320 and then label the tank.

CGA 320 is a valve that is used on CO2 tanks. The people that fills the tanks knows this an will know what to fill it with.

 

[rflud]

You need to change the valve on it to a CGA 320 and then label the tank.

CGA 320 is a valve that is used on CO2 tanks. The people that fills the tanks knows this an will know what to fill it with.

Thanks Mad, I didn't know what valve it needed. So you are saying that this shouldn't be a problem?

 

[Grunt1058]

A while back (in my Jeep days) I picked up a SCUBA tank to use for OBA. Plan was to run a engine powered pump and use the SCUBA tank as a resivoir. Later decided against using the SCUBA tank due to lack of mounting options. So, I'm building 2x4" Square tube rock sliders that'll double as air tanks instead.

 

[scottmcwms]

Has anyone ever used their roll cage as an air tank? All you would have to do is cap off the ends and drill holes to make it one continuous tank. Anyone???

 

[DBrown]

I used a fire ext. tank for the OBA on my BII. the tank will work but I would not use C02. I would just go and get a York A/C compressor and mount it with the factory belt setup on your motor. then wire it up to kick on when you need it and run an air line to it.

it is one of my favorite cheap mod's......and you never have to have it refilled just kick on the compressor.

 

[Broncobowsher]

As I started diving before I got into the Broncos, I started with a Scuba tank for my first source of air. The steel 72 filled to 2250PSI could easily do 4 33” tires as I left the cinders. That was from pressure so low the pressure gauge wouldn’t show to full highway pressure. It would use less then half a tank. The simplest way of doing this is the $10 air chuck that plugs into the BC fitting on the regulator. I had a spare first stage, knew the dive shop (did some work for him as well) and put together enough parts to have a dedicated offroad regulator. Cut and spliced in a standard quick connect that flows much better then the fitting on a BC.

That set up worked for a couple of years, then I got a CO2 tank in a raffle. The CO2 has much deeper lungs (the gas is condensed into a liquid) but is another tank that I have to deal with. The air cost $4 to fill, the CO2 runs $14~$20. Actually I was getting the air for free since I would go in and help out with the or filling tanks for him. Toss mine in for a free. Hydro is the same, every 5 years. Air has another advantage, you know how much you have by the pressure. CO2 you have to get the bathroom scale out and remember if the empty weight you wrote down included the regulator or not. Air also works in any position. CO2 must be upright or you start shooting liquid through the regulator.

There is one problem with running a scuba tank. Dive shops won’t fill it unless you are certified. Part of the industry self regulation (keeps the government out). I have considered going back to air. Just not in any hurry. Besides, I like the idea that if I ever needed to finish a weld and the welder was out of gas, I could just grab the CO2 tank out of the Bronco and hook it to the welder.

So does a scuba tank work, yes.
Which is better? Depends on what you have available.
Which is safer? Well the air is under higher pressure, but CO2 is an axiphient. Both bottle are safe (not going to blow up). But if you cook one off in an enclosed vehicle and blow a burst disk, air isn’t going to kill you but it will be louder. Trust me you are not going to sleep through a blown burst disk, I have had a scuba tank pop one in the closet in the middle of the night and another dump 10 pounds of nitros oxide in the living room. Both of them woke me up. If you can sleep through one going off, you are already dead.
In a pinch, the CO2 tank could be used as a fire extinguisher. If you can get the valve off real fast, turn it upside down, aim it and open the valve. It could pass as a last ditch fire extinguisher.

If didn’t get the CO2 in a raffle, I wouldn’t be in the market for one and I would still be using the scuba tank. Since I have CO2, that is what I use. If I ever run out and still want to go out for a weekend, I’ll just throw in one of the AL80s and the regulator to go with it. I haven’t checked, but I think an AL80 will fit in the CO2 holder.

 

[bax]

20 ounce paint ball tanks might work good. Small and cheap to fill. good enough to operate arb's.

 

[Rustytruck]

My 2" roll cage is drilled and tapped for air from my york compressor. I run 125 lb burst valve on a 115 psi system pressure. it works but it still isnt alot of volume. Maybe one 33" tire from 15 psi to 30 psi if your lucky. It will produce enough volume to seat a bead though or maybe a couple of blasts on an impact. I could run the pressure higher but fear alot of pressure on an untested system. Our stress engineer at work says the tube wont burst until over 1,000 psi but the welds are the big issue. I have run it this way for over 15 years. Just remember to have your pressure taps at the very bottom of the leggs of each tube. you dont want to build up moisture and rust out a tube next to your feet.

 

[House]

I like compressed air over CO2 for my tires and my paintball markers...