Portable Air Tank Q's

[Skyetone]

I had an old 4 gallon air tank from smith and edwards for years. I made it into a portable air tank by having a filler valve off tires, and a female air hose coupler. I got it filled to 80psi. But it barely filled one 35" BFG. How is it that the regular tanks work? I know that the co2 ones expand the air somehow.... But how do regular air tanks work? I have no air compresser to the tank. I thought I could just fill it and go to the trail. Fill my low tires and drive and refill it for the next run.

How does it work? I know guys have bumpers as tanks. WTF?
I know This thread doesn't make much sence, but I don't know how to word it.

 

[chuck]

Ok here we go, stand back I am going to try to help>
Most of the tanks out there work in one of two ways. Either you fill a large air tank with compressor air (CO2). Or you use an air tank that is designed to be filled with licquid compressed oxygen.
And for the bumpers that are air tanks. Most people that have these also have a compressor of some kind. Hopes this helps.

 

[H-K]

Hmm, yeah, how do you figure out how large an air tank you need? Anybody here converted their stock Jeep front bumper tube into an air tank? I've heard of this being done, but was wondering how much air you can really pack in that little tube. Is it enough to put 20 lbs in a flat 33x12.5? How much air tank capacity does one need to fill the volume in a 35x12.5 tire to maybe 25 lbs?

 

[muleskinner]

You use a bumper or tank for volume from your compressor. Co2 is a liquid in the tank, so you need to make sure you get a tank without a dip tube in the bottom. If you don't you will draw liquid instead of gas. You want to draw the Co2 gas from the top or the tank. if you open the valve too fast you will get liquid out of it regardless. Co2 is about 1800 psi. and will last quite a while. I don’t see why more people don't use Scuba tanks, they are compressed air @ 3000 psi. That would fill plenty of tires and they only cost $3 to fill

 

[H-K]

Originally posted by muleskinner
I don’t see why more people don't use Scuba tanks, they are compressed air @ 3000 psi. That would fill plenty of tires and they only cost $3 to fill

Now there's an idea. Hmm... will standard air-tank fittings be up to that kind of pressure? I guess a regulator would help, but the regulator would have to be kinda beefy?

 

[grinch]

No stantard air tanks are not rated to hold 3,000 psi.... if you go that route just get a scuba tank or a small co2 tank... they are made for that pourpose..... If you have ever seen a tank that wasnt rated for that much psi explode youll realise why i say this.... lets just say they make one hell of a rocket ship....
Im not to fond of airtankd built into bumpers or roll cages for one reason and one reason only.... bumpers and cages are built to take an impact... imagin punchering or hitting one and having it throw shrapnell at you. It most likly wont happen but there is still a good chance.
If your going to run onboard air do it right. Either get a compressor i.e. an a/c compressor converted over for air or electric compressor. Then run a protected air tank. Or buy a tank made to hold high psi gasses... i.e. co 2 tank or scuba tank....

 

[Skyetone]

I know how to figure out volume(gallon) per square inch of water, but would air be the same?
I was afraid to fill my tank to the point of burst for obvious reasons.
How much does a scuba tank cost to go buy to fill? 2-$300? I am looking for a easy inexpencive rought to fill up tires. I have a cheesy 12v air compresser. But was hoping for an eiseir and faster way to do it without building on-board air.
I guess it is a volume thing overall, but how can something with 3000psi at 2gallons of volume actually have a reasonable amount of volume in comparison to say even 100psi at 2gallons?
Why does CO2 make a difference? Does it expand once airborn?

 

[muleskinner]

You can get good used Scuba tanks for $100. They make an adapter for Paintballing that is around $50 that you could use to fill tires with. You don’t need a extra tank with this setup. You'd probably be into the whole thing $175-200 total.

 

[cruiseroutfit]

Originally posted by muleskinner
You can get good used Scuba tanks for $100. They make an adapter for Paintballing that is around $50 that you could use to fill tires with. ...

Where would be the best place to look for this stuff?

I have an old regulator that was used for years on a tank for air... It was given to me when the guy did the York setup and no longer needed to have an air bottle. Well I took it to Airgas yesterday and they laughed... turns out the regulator I had was previously an Acetylene torch regulator... so basically its garbage...

I still want to do a CO2 or Oxy bottle... any info is appreciated...

 

[Skyetone]

Swap meet We are a desert there EVERYWHERE

Anyways.... I don't mind spending a little money on the inissial setup, JUst loking for quick and easy. I'll stick with the 12v POS for now. But maybe next summer.
Still doesn't explain my prior Q's though

 

[muleskinner]

Originally posted by cruiseroutfit


Where would be the best place to look for this stuff?

I have an old regulator that was used for years on a tank for air... It was given to me when the guy did the York setup and no longer needed to have an air bottle. Well I took it to Airgas yesterday and they laughed... turns out the regulator I had was previously an Acetylene torch regulator... so basically its garbage...

I still want to do a CO2 or Oxy bottle... any info is appreciated...

Go to any scuba store and they usually have used tanks for $100. Here is an adapter for $59 with a quick connect for a hose.

I wouldn't even bother with a reg. Just open the valve slowly. I've been using a HP air bottle for tires all my life and haven't had any probs.

 

[muleskinner]

Originally posted by Skyetone
I guess it is a volume thing overall, but how can something with 3000psi at 2gallons of volume actually have a reasonable amount of volume in comparison to say even 100psi at 2gallons?
Why does CO2 make a difference? Does it expand once airborn?

You answered you own question Pressure. The same volume (2 Gal) with alot more air compressed into it. 3000 VS 100 PSI