Portable Air Compressors

-H-
I have a 10# CO2 and a Truck Air 12v electric as a backup. I'm getting close to an OBA using electric compressors but I can't recommend that route yet.

CO2 Pros:
* Reasonably priced if you DIY. The Power Tank is a nice rig but expensive. Jody's Outback system seems to be priced right and is well thought out.
* Quick tyre inflation using 150psi regulator.
* 10# tank can typically do 30+ tyres (depends on size and begin/end pressures)
* Supposedly can reseat tyres if needed.
* Portable. I used mine w/air tools in the back yard to dismantle a wooden structure.
* Works great with air tools. Can get a 100psi regulator as a spare and use it for air tools.
* Can double as a fire extinguisher

Cons:
* Refilling becomes a chore and the $12/refill starts adding up.
* If you only have one tank you end up refilling before the tank is empty...
* or... you end up running out at an inopportune time. (I'm considering a 2nd tank)
* They're kinda big and take up valuable space. Not so much of a problem with our 80s.
* They can blow the safety. Fortunately mine blew in the garage with nobody in the truck.

That's all I can think of... probably missed something.

I would do the CO2 again.

-B-

 

Riddle me this..........


How does a tire filled with CO2 react to temperature/pressure changes vs a tire with plain old air in it?



D-

 

Nothing scientific, but seat-of-the-pants is that CO2 doesn't change much. However, I have noticed that bicycle tyres, with rubber tubes, don't seem to hold CO2 very well. I need to try this with new tubes though. As I recally, the CO2 molecules are smaller than air molecules. I notice *no* issue at all with the tubless tyres on the truck. They hold the pressure extremely well... at least as good if not better than normal air.
-B-

 

No,

Not leaking. I'm refering to pressure changes due to temperature changes. IE, 4 matching tires, 2 with CO2, 2 with air. Cold pressure in all 4, 32 lbs. Drive like hell for 40 miles, Hot pressure?



D-

 

CO2 is "bigger" than either O2 or N2 which normal air is comprised of (about 98%), so it's not a size issue with respect to leakage. CO2 will compress more easily than will O2 or N2 (it liquifies at room temperature at 625psi), but I don't think you'd notice that in a tire --at least I'd be really surprised. Temperature extremes would have to be quite large to notice a difference I think.

But density of CO2 is higher than either O2 or N2, so it's possible you might "feel" a differnece in the tires. Having never done this I can't tell--have you noticed it B?

Tom

 

Council is Badgering the witness..............


Does it, or does it not, result in a different pressure?

 

B - How did you blow the safey? Overheating?

 

The vendor over-filled his tank....... :whoops:

 

Hugh,
Yep, it was overfilled by about 4 lbs. Ironically, we weighed it immediately following the fill. This was the first time I used anything but the bathroom scale and I wanted to get an accurate reading; full and empty. This was on a warm summer day with the tank laying horizontally in the cargo area (strapped down of course.) It was parked in the sun for a few hours, then I went home and parked it in the garage with the garage door closed. Went inside for a few minutes and when I came back out to the truck and opened the passenger door there was a very pungent smell. I recognized it immediately as CO2. Checked the tank and it was empty and the safety was blown. There was a slight coolness to the rubber Husky liner in the cargo area but other than the smell, and a little condensation, you couldn't tell it had discharged.

Took it back to the place that filled it and weighed the empty tank on their scale. They had put 13.7 lbs of CO2 in it. They replaced the safety (actually the whole valve....) and refilled it at no charge.

The bad news is that now they won't put in a full 10#; usually about 8-9#. I haven't watched the process but apparently they empty the tank, then hook it to the filler valve and put CO2 in for a while... I think they just guess at the weight. I now weigh it every time before I leave the store.



-B-

 

Go CO2. I have a 20# tank and it works great. Much better then any compressor. I dont like the ARB compressor. For the money I would buy a cheepo JT whitney model.

 

Could use Nitrogen instead of Carbon Dioxcide.

I got a Super Works Compresor from Dad and Mum for my 18 Birthday. - About $70.00 from Super Cheap Auto. - Still Works.

 

MR. Ferguson!!

Do you have access to Nitrogen??? I do because i work with millitary aircraft and that is all we use in the tires.... much more stable than dry air ... it dosen't fluctuate with temperature as much and seems to hold pressure longer.... of course with Acft we sevice the tires every couple of days. but even if i did run nitrogen in my tires i don't see an easy way of making i portable, it doesn't liquify like CO2 and you would need a bottle that can hold at least 3000psi to hold enough gassious N2 to be usefull... not to mention really high pressure regualtor.

i'm not saying it can't be done i have thought about converting a scuba tank to hold it and filling up at work.... but i havn't found a regualtor i can adapt to the tank

CO2 just seems easier

just my $.02

dan

 

No, Though it is becomeing very common for Tyre Shops to offer it.

 

C-Dan,

To answer your question, CO[sub]2[/sub] reacts to temperature changes much the same as the air you breathe does. Very little difference. In my experience with CO[sub]2[/sub] in all my vehicles tires, I just can't tell any difference.

Beo,

You need to find another place to get your tank filled!! Those guys are just dangerous!

Jody.

 

Back to the question about on board air.....
York 10cfm here! Endless amounts of air that can easily run air tools and fill tires as fast as my shop compressor. Good Electric compressors are waaaay too expensive, C02 would be my next choice but I'm already pressed for storage space. You can set up a york for just blowing up tires for under $100. That is cost of the York, brackets to mount and any miscellaneous hardware. I'm estimating $200 total for my setup that will include a tank, in cab guage, ARB provisions, quick disconnects F+R and automated pressure regulation. Right at the cost of a decent 12v compressor.

 

Thanks Jody.

One of our club members is a fire fighter. He uses a couple retired breathing air tanks for his air supply. He fills them at the fire station. They have something like a 4000psi compressor there

 

Jody,
It's a pretty big outfit and they fill it when I bring it in. No drop-off, pick-up. No waiting. The price is reasonable ($12 or so.) They have thousands of various tanks out back and do all kinds of industrial and medical gasses. Their specialty is nitrogen and they supply it for all the businesses in the state.

I am hoping this over-fill was an outlier and they now know me and know that I'm going to weigh the filled tank on their scale before I leave. I pretty sure it won't get over-filled again but the underfilling is bugging me a little.
-B-

 

Yeah Beo, underfills kinda suck since you can't just hook it up and "top it off". You have to vent the entire contents and start from scratch every time.

That brings me to my CO[sub]2[/sub] tip-o-the-day:

[glow=red,2,300]Use up as much of your fill as you can before you refill, 'cause you're gonna lose what's left.[/glow]

Jody.