For awhile now, I've been thinking about buying a CO2 tank so that I could
create my own carbonated drinks... The ability to use it to quickly inflate
the tires on my XJ and my plane without having to use a 12V compressor was
definitely a potential bonus... Previously, I had used a BBQ propane tank
that I had converted for air storage and I would fill it up from my home
compressor before taking my XJ out or before heading down to the airport (my
plane has a very slow leak in the tires)... Unfortunately, a BBQ propane
tank just doesn't hold that much air although you could pump it up to 300
psi if you had a compressor that went that high... Although it would be
possible to fill the tires with propane, running air tools off of propane
would likely be rather hazardous, so I finally broke down and decided to go
the CO2 route...

I went to a local beverage equipment supply company and picked up a 0-160
psi CO2 regulator for $45... The outlet fitting used a 1/4" NPT thread, so I
replaced it with a 90 degree street elbow and air tool quick connect fitting
so that I could reuse my existing hoses and air tools... I stopped off at a
local welding gas supply store and was able to get a brand new steel 20# CO2
cylinder for $95 which included 20# of gas... There was also a local company
that had new 20# aluminum cylinders for sell for $100, but that didn't
include the CO2, but it did include a handle / valve guard... At that point,
I had a portable CO2 tank that could either run air tools or fill tires...
Total cost, including the fittings, approximately $145...

The Power Tank systems are available in 10# and 15# tanks... Considering the
fact that the cost to refill a 20# tank is basically the same as it is to
refill at 10# or 15# tank, it is more economical to go the 20# route,
although the tank does take up a little more room... The tank is a little
shorter than a typical AL80 scuba tank and 8" in diameter instead of
7.25"... The gas capacity of 20# of CO2 is around 171 cu-ft -- twice what
basically the same size in a scuba tank would be in addition to having the
added advantage of being able to make carbonated drinks...

There are some fixed 150 psi regulators available that are more compact and
less likely to be damaged if you were to drop the tank on its side, but
since most air tools require less than that, I would still have had to put
an air tool regulator on the line to reduce the pressure to something more
acceptable... Since I was going to be using the tank for soft drink
carbonation also, being able to adjust the pressure at the tank was rather
desireable...

Ok, now for the drink carbonation... First, I went to Pep Boys and bought
four metal schraeder type valves that are normally used for wheels... I
removed the black rubber washers from it since they would have imparted a
tire store smell / taste to the drinks (this is the same reason that you
would not want to use the rubber tire stems)... I then picked up some
O-rings from the faucet section of my local home improvement store
(Lowes)... I took a 2-liter bottle cap, drilled a hole in the top to match
the size of the metal valve stem, inserted it from the bottom of the cap
along with the O-ring and put the washer and nut on the outside of the
bottle cap... I then filled up the bottle to within 2-3" of the top with
cold water, put the top on loosely, squeezed the bottle so that all the air
was out of it, and then inflated it to 40 psi... I then shook the bottle up
for awhile and it was quite noticeable that the water was absorbing the CO2
since I could feel the pressure in the bottle decreasing... I added some
more CO2 without opening the top, shook it up more until the pressure had
noticeably decreased, and then repeated this process one more time... I then
removed the top and had a nice cold glass of carbonated / seltzer water...
Total time to make the bottle of carbonated water -- approximately a
minute... Cost -- probably less than $0.05... Since this time, I have
experimented with other drinks... I've made carbonated sugar free Kool-Aid
for my daughter's lunch... I've found that Dr. Pepper is really sweeter than
I prefer and diluting it by 50% with carbonated water is quite acceptable...
I've tried carbonated chocolate milk -- I'm not sure that I like this one
though since the carbonic acid that is created when water is carbonated
tends to alter the taste of the milk to the point where it is somewhat
'different'... Probably one of those tastes that you just "have to get used
to"... Perhaps more sugar in the drink would offset the taste somewhat...
Next experiment will be carbonated sweetened ice tea and perhaps a
carbonated cafe mocha type of drink... Haven't tried direct carbonation of
alcohol yet though... Total additional cost of four schraeder type fittings
and a box of O-rings, approximately $10...

Now that I have the CO2 tank, I guess I'm going to have to get into MIG
welding so that I can use it as a shielding gas...

BTW, before I tried carbonating drinks, I tried oxygenating them by putting
a quick connect air tool fitting on my O2 welding regulator... Although it
is possible to get the drink to absorb the O2 and be somewhat bubbly, it's a
lighter bubbly than carbonation and doesn't have the same flavor (due to the
carbonic acid that is formed during carbonation)... The O2 also comes out of
solution with the beverage more readily, thus you need to drink the beverage
more quickly before it goes 'flat'... An interesting experiment, but not one
that I would deem worth repeating...

 

I would probably keep the regulator dismounted and use a type of tank with a
cap, like on an O2 bottle, I wouldn't want that sucker busting off a
regulator while in a collision. Similarly, I would securely mount it to keep
from getting clonked in the head in a rollover.

What is the expansion coefficent of CO2? we used Nitrogen in race car tires
because it doesn't change the tire pressure when it heats up as much as air.
This might be worth another experiment, measure temp variation hot and cold,
say when you have them down for crawling and the temp goes way up after ten
miles or so from sidewall flex.
--
Paul Calman, Hathaway Pines, California

 

I would probably keep the regulator dismounted and use a type of tank with a
cap, like on an O2 bottle, I wouldn't want that sucker busting off a
regulator while in a collision. Similarly, I would securely mount it to keep
from getting clonked in the head in a rollover.

What is the expansion coefficent of CO2? we used Nitrogen in race car tires
because it doesn't change the tire pressure when it heats up as much as air.
This might be worth another experiment, measure temp variation hot and cold,
say when you have them down for crawling and the temp goes way up after ten
miles or so from sidewall flex.
--
Paul Calman, Hathaway Pines, California

 

I would probably keep the regulator dismounted and use a type of tank with a
cap, like on an O2 bottle, I wouldn't want that sucker busting off a
regulator while in a collision. Similarly, I would securely mount it to keep
from getting clonked in the head in a rollover.

What is the expansion coefficent of CO2? we used Nitrogen in race car tires
because it doesn't change the tire pressure when it heats up as much as air.
This might be worth another experiment, measure temp variation hot and cold,
say when you have them down for crawling and the temp goes way up after ten
miles or so from sidewall flex.
--
Paul Calman, Hathaway Pines, California

 

Grumman-581 wrote:
> compressor before taking my XJ out or before heading down to the airport (my
> plane has a very slow leak in the tires)...

You're comfortable landing on tires that have slow leaks?

 

Grumman-581 wrote:
> compressor before taking my XJ out or before heading down to the airport (my
> plane has a very slow leak in the tires)...

You're comfortable landing on tires that have slow leaks?

 

Grumman-581 wrote:
> compressor before taking my XJ out or before heading down to the airport (my
> plane has a very slow leak in the tires)...

You're comfortable landing on tires that have slow leaks?

 

"Simon Juncal" wrote ...
> You're comfortable landing on tires that have slow leaks?

They've always had a slow leak in them... They'll stay aired up for a few
weeks and then it will be noticeable that they need a little air... It seems
that every tubed tire that I've every owned has had a slow leak in them, be
them bicycles or aircraft... The tire on my aircraft has had this same slow
leak for the last 4 years... If it started leaking faster, I would be more
concerned about it, but with this slow of a leak, I'm not all that
concerned... At the very worst, the tire only needs to hold air for 5 hours
anyway... Past that point, I'm either on the ground or my engine has gotten
rather silent and I've thus got a problem that makes any decrease in tire
pressure a rather minor inconvenience...

 

"Simon Juncal" wrote ...
> You're comfortable landing on tires that have slow leaks?

They've always had a slow leak in them... They'll stay aired up for a few
weeks and then it will be noticeable that they need a little air... It seems
that every tubed tire that I've every owned has had a slow leak in them, be
them bicycles or aircraft... The tire on my aircraft has had this same slow
leak for the last 4 years... If it started leaking faster, I would be more
concerned about it, but with this slow of a leak, I'm not all that
concerned... At the very worst, the tire only needs to hold air for 5 hours
anyway... Past that point, I'm either on the ground or my engine has gotten
rather silent and I've thus got a problem that makes any decrease in tire
pressure a rather minor inconvenience...

 

"Simon Juncal" wrote ...
> You're comfortable landing on tires that have slow leaks?

They've always had a slow leak in them... They'll stay aired up for a few
weeks and then it will be noticeable that they need a little air... It seems
that every tubed tire that I've every owned has had a slow leak in them, be
them bicycles or aircraft... The tire on my aircraft has had this same slow
leak for the last 4 years... If it started leaking faster, I would be more
concerned about it, but with this slow of a leak, I'm not all that
concerned... At the very worst, the tire only needs to hold air for 5 hours
anyway... Past that point, I'm either on the ground or my engine has gotten
rather silent and I've thus got a problem that makes any decrease in tire
pressure a rather minor inconvenience...