Yup, which is why a smaller tank (than say a compressed air tank or nitrogen) will fill more tires.
It's also why a gauge showing pressure in the tank is worthless, as far as determining how much CO2 remains. As long as there is a single drop of CO2 in the tank, the pressure in the tank is the same
A tank was to be weighed to detemine the amount of CO2 remaining.
When released it actually gives off CO2, not air
The liquid CO2, when not under pressure, converts to gasous CO2 and that's what goes into the tires. CO2.....




Fred

 

How accurate is the 'weighing' method to figure out how much CO2 you have left?

I am debating whether to go with CO2 or a compressor, but don't like the idea of being stranded without air cuz the CO2 pooped out.

 

Pretty accurate. 10lbs of liquid is 10lbs of liquid. Weigh your tank on empty... go get it filled... weigh it again: it should be tank_weight + tank_size_in_lbs
If not, they didn't fill it all the way. Anyway, when weeling, just weigh it and that will show you how many lbs of liquid you have left. If you are super anal you can test the weight after 4 complete tire fills and figure out how many fills you get per tank.

 

Hey there Jared. Have not seen you here in a little while.

I have learned a bunch in this thread and have decided to make a system myself. In addition to the info here which has not substanciated any major pitfalls of a homemade system, seeing Chris Slosurfer air up 3 vehicles without a break using the $35 regulator really sold me. Maybe in a really cold environment the freezing reg could be an issue.

Thanks for all the info.

 

Weigh it empty, weigh it full. Keep the same fish scale with you.

Tank pressure is useless.

I have a 15 pound tank, I am debating carrying a cheapo 5 around just in case so I can swap the regulator when the other runs out. I usually just cheat though and try to go out with a topped off tank.

Go CO2.

Corey, that was one of the least scientific answers I have ever seen. Right words, not so good on the order. I just tell people it works.

Nitrogen is better.

 

So you wheel alone .....




Fred

 

And work it does
Work it work it work it...

 

I've been around, just mostly posting in the 4th Gen section. I rarely have anything useful to add!!

Mark (Expat) made his own C02 system, and it ended up pretty nice, but still cheap. Here's his writeup on it.

 

Are there any issues with storing a CO2 tank in a hot car?

 

Why get an adjustable reg?
You don't want to run air tools much above 100 psi-- or air lockers for that matter. And airing up tires takes less time with more pressure--150 psi or better fair airing up is nice.
And so you need a gauge.
And I would argue two is nice--1 for the tank pressure and one for the regulated pressure.
I want to see the tank pressure becasue it can and does change. I have seen it anywhere from 300 pounds to over 2500 psi. The amount of CO2 in the tank and ambiant air temperature both affect internal pressure.
I like to push the envelope when getting the tanks filled up and usually squeeze 16 pounds of CO2 into my 15 pound tanks. I then blow off a little until the valve blows clean (no ice chunks) and then hook up the reg and use it right away. Keeping them completely filled it is nice to know what kind of pressure you are keeping it under since the blow off valve is set at 3000. I have only lost one tankful of CO2 to a blow off valve and that was because I hadn't bothered to check the tank pressure and it was sitting in the back of my rig on a 100*+ day.
You can also tell that the tank is getting low without unbolting it and picking it up by watching the internal pressure gauge. As it drops below 300 psi you know you are running low.

 

If you tank is not overfull you should have no issues. I would not leave it in a car parked in the sun with the windows all rolled up though--A car interior can get to 170*+ and a full tank of CO2 may hit 3000 psi and blow the valve--no harm done, just need a new valve and you wasted 12$ or so worth of CO2.

 

I had my first Powertank in the back of my 4Runner for years in direct sunlight since my rig and present rig are outside 24/7/365 all the time.

Never had an issue, but I also tell the shop to put in 9.75 lb of C02.
Of course as you use it goes down, but if it was hot out when the filled tank went back in, having it a tad under 10 lb can help.

 

Here is a pic of my OBA system-- still tweaking it--Oasis compressor on 24 volts and two 15# CO2 tanks for backup.
Also plan to build an expanded metal shelf and divider for gear to reclaim a bit of my cargo area while still supplying plenty of room for the system to keep cool.

 

Wow, an Oasis and two CO2 tanks!

Do you have a bigger pic of that setup?
Is the Oasis mounted in the back or just in a metal box... hard to tell from the pic.
Any issues with oil leaking out of it?

 

I have a cobbled system.

It freezes up.

Here's the deal. I have all of 30 bones into my whole system. I envy guys who blast 4 tires at 250 psi, no freeze, and i am freezing at 110.

I have a valved guage set up so i can read my tire pressure, with a good valve clamp. I can fill, shut the valve with 90deg twist, read my tire press, and open to fill with the flick of a thumb. I have yet to see a 0-60psi guage that will handle PT output. As soon as i find one, i'm upgrading to a PT regulator.

A pt is worth the money.

 

Mogger, your truck was impressive at Mike's. I think you should describe your air needs when posting that pic. Yeah, 40's take a lot of air, but you use it for other stuff too.

I only had an issue in the truck once. It had been overfilled and blew. Funny thing was I didn't know it, went to Moab and had no juice. Nothing else happened except blowing the release seal, which I then replaced.

Some people seem really hung up on the running out thing. I am usually with other people, so SOMONE always has air. If not, I have never been too far away to just limp in on low pressure. Though it is not optimal, driving at 15 for an hour or so is not a big deal.

If you are still worried about that, then get a 20 ounce, 2.5 or 5 pounder to stash just in case. Lots of the cruiser guys who do expedition stuff run two bottles just in case. That way if you really need it, you can go and go and go.

 

I agree a 0-60psi gauge is not going to work. I got mine at a beer and winemaking supply shop, but it is a 0-300psi gauge. Somebody just gave it to them because it wouldn't work for their systems. That is why I suggested checking those places, sometimes they have stuff sitting on their back shelves that they just want to get rid of. Hence walking out of their with it for $20. If it starts to give me problems, I will upgrade it to a PT regulator. (Knocking on wood). Just because it is cobbled together, doesn't mean it is crap. You can use quality products and still not spend a ton of dough. Heck, the best rigs out there would have to fall in the "cobbled together" category. You just have to be patient and shop around. If you have the dough, it sounds like PT is the way to go.

 

Axle, you mean an inflation guage?
If so, this is what I use.
It also deflates by pulling the trigger half way.



http://www.griotsgarage.com/catalog....3500&SKU=92549

It handles the PT at full blast.

PT also has similiar inflation guages on their site.

 

Yep. It was either going to be "4Mogger" or "Lots-O-Air"
The 40's are on CTIS that I adapted from a Hummer H1. A simple manual regulator mounted partially under the driver's seat adjusts the air in all four tires from 0 to 30 psi. Zero to 30 for all four tires with the Oasis on 24 volts (also runs on 12) takes about 5 minutes. With the CO2 it is more like 2 or 3 minutes. CO2 is simply awesome! My favorite toy on my rig is CO2.
Also running full air suspension, active so it continues to use air as you drive.
And finally the F and R lockers have been converted to air rams. Keep the system at about 120 psi to keep it all happy.
I want to add a larger second air tank under the cargo area--at least 10 gallons or so--and I need to change the plumbing around a bit--but it is getting there.

 

Corey,

Yes and no. Ive got a hard wired guage now. It sits right after the regulator. So, my system looks like this: Tank, regulator, quick connector male, quick connector female, 90 deg ball valve, t-joint w/0-60 guage, 150psi max, quick connector male, quick conn female, then hose. This enables me to hook up the hose to the tire, open the 90 valve, and walk away. I can check the tire pressure, and then fill or whatever, and go from there. I hate stooping over to fill the tire, so i got a hands free set up built.