Re: 1991 ranger brake problem - CO2 & O3

"Bob La Londe"  wrote in message news:vh5j5j$2v6fp$1@dont-email.me...
On 11/13/2024 4:58 PM, Jim Wilkins wrote:

"Bob La Londe"  wrote in message news:vh38u5$2dg8a$2@dont-email.me...
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On 11/13/2024 3:09 PM, Snag wrote:
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   I thought it was exposure to sunlight/UV that caused most of the sidewall degradation ... or are those aftermarket tire covers (in particular for RV's and campers) just another scam ?

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Yeah I don't know for sure.  UV is certainly capable of damaging a lot
of things.  I do know CO2 is an issue with some rubbers.  I was told
by... well somebody... that tires were among them.
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Nobody likes to be wrong, so I did some look ups.
CO2 is said to contribute to the breakdown of rubber on several sites.
Some say "distressed" CO2 and others just generically say CO2.  O3 also
contributes to the break down of rubbers and is more reactive.  Then I
looked at concentrations per a few other references.  They say CO2 is
present at ground level from 300 to 900 PPM (million) where as O3 is
typically present at 20-30 PPB (billion).
As to whether the difference in available molecules makes a real
difference in which has more net affect I do not know, but the numbers
do make you think.
I recall now where I first ran across the reference to CO2 and its
reactivity with rubbers.  I don't recall exactly who it was (could have
been Bob Sterne), but it was in regards to tuning, building, and
repairing airguns.  Admittedly air can be quite distressed in a spring
piston gun generating enough sudden compression to detonate oils or in a
PCP gun where air can be stored at pressures as high as 4500PSI.  Over
300 bar for the metric crowd.
I'm not saying I was right and you were wrong.  Not at all.  I could
very well be wrong still.  My "expertise" with material science is
limited to rote memory and blue collar experience.  I'm just stating it
might not be as cut and dried as as it seems.  I would argue in full on
flat Earther fashion... "Nothing is ever totally settled science."  LOL.
Bob La Londe
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While researching I saw some mentions of CO2 damage too, mainly with high pressure gaseous and liquid CO2. It may have been physical rather than chemical damage from absorbed gas and rapid pressure changes, in oil well instruments. I didn't see any for atmospheric pressure on tires. I'm burning through my monthly 10GB data allotment too fast to do more research on it.