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Old November 2nd 06, 07:33 PM posted to rec.aviation.owning
Mike Noel
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Posts: 206
Default Replacing innertubes without replacing tires?

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.