Replacing innertubes without replacing tires?

Gig 601XL Builder wrote:
"Ray Andraka" wrote in message
...

Gig 601XL Builder wrote:



Fill them with Nitrogen they won't leak as much. Not that I've tried it.

How do you figure that? Air is already mostly nitrogen. Why would a
higher concentration of nitrogen leak any less than plain old air? The
difference in atom sizes between nitrogen and the other major constituents
of air is on the order of a few percent, so even the other constituents
aren't going to leak out leaving just nitrogen.


As I said I haven't tried it but there are 398,000 hits when you Google
Nitrogen filled tires. I saw and ad for it in one of the aircraft mags the
other day and hadn't really looked into it that much. But glancing at the
Google results the opinions are mixed between works well and snake oil.



There are reasons for using nitrogen in tires, but leakage isn't one of
them. From what I understand, high pressure tires often need nitrogen
because if regular air was used the high pressure of the oxygen mix
becomes combustible and can lead to tire fires. In our spam cans
though, the pressures aren't high enough to cause problems. There's
also the convenience thing if you happen to have bottled nitrogen in the
hangar, and finally some have said that it keeps the rubber from
oxidizing, but I doubt that is a real issue since the outsides will
deteriorate long before the inside oxidizes enough to be a problem.

I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

"Ray Andraka" wrote in message
...
Gig 601XL Builder wrote:
"Ray Andraka" wrote in message
...

Gig 601XL Builder wrote:



Fill them with Nitrogen they won't leak as much. Not that I've tried it.

How do you figure that? Air is already mostly nitrogen. Why would a
higher concentration of nitrogen leak any less than plain old air? The
difference in atom sizes between nitrogen and the other major
constituents of air is on the order of a few percent, so even the other
constituents aren't going to leak out leaving just nitrogen.


As I said I haven't tried it but there are 398,000 hits when you Google
Nitrogen filled tires. I saw and ad for it in one of the aircraft mags
the other day and hadn't really looked into it that much. But glancing at
the Google results the opinions are mixed between works well and snake
oil.

There are reasons for using nitrogen in tires, but leakage isn't one of
them. From what I understand, high pressure tires often need nitrogen
because if regular air was used the high pressure of the oxygen mix
becomes combustible and can lead to tire fires. In our spam cans though,
the pressures aren't high enough to cause problems. There's also the
convenience thing if you happen to have bottled nitrogen in the hangar,
and finally some have said that it keeps the rubber from oxidizing, but I
doubt that is a real issue since the outsides will deteriorate long before
the inside oxidizes enough to be a problem.

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?

--
Jim Pennino

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Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call it
using N2. There is a lot more N than O.

Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
news
Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call it
using N2. There is a lot more N than O.

Nobody but you used the phrase "use O2", notice the phrase "partial pressure"
in the original post.

--
Jim Pennino

Remove .spam.sux to reply.

wrote in message
news
Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
news
Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but
the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call
it
using N2. There is a lot more N than O.

Nobody but you used the phrase "use O2", notice the phrase "partial
pressure"
in the original post.

Read the first sentence in Mikes post and notice the phrase "I don't know
the practical aspects of N2 v O2 in modern tubes,..."

I always replaced tires and tubes together. For the additional $30 for a
new tube, I always thought it was false economy to reuse them. As some
have acknowledged, the tubes stretch and may fold upon reuse. I usually
see cracking around the valve stem on a used tube. Perhaps reuse would
be an option if we flew 250 hours a year and wore out tires sooner. But
we usually have tires for 4 years or so. By then, I usually see the
valve stem starting to crack and the sidewalls cracking on the tires.

It seems like cheap insurance. But, others swear by reusing tubes. This
is a pretty good case of how different people will accept differing
degrees of maintenance. Absent any Advisory Circular or maintenance
manual prohibition against reusing tubes, it is "legal" to do so.

Nitrogen in the tires? I don't even use nitrogen in the struts.

Good Luck,
Mike