Bill,
Very good information and question. The most recent three tests have all
been done with temperatures between 40 and 50 degrees F so that wouldn't appear
to be a factor. A wild guess would be that the high humidity helps keep the FV
from evaporatiing out of the rubber so the short chains remain separated.
The tires are always shrinkwrapped after the application of FV which definately
appears to help seal it in. Now the idea is to surround the tire right after
racing with a water soaked towel and shrinkwrap. But how much FV does one
add to the water so the tires are soft but don't turn to mush?
Kevin
In a message dated 4/14/2004 11:05:19 AM Eastern Standard Time,
martin_93555@yahoo.com writes:
>
> *** "Martin's" <martin_93555@yahoo.com> writes: ***
>
>
> Can't argue with observations, but it doesn't seem to
> make sense.
>
> Rubber is a blend of short and long-chain molecules.
> With age, the shorter ones link up and it tends
> towards more long-chain. The reaction is dramatically
> accelerated by heat, thus "heat cycles" on tires.
> Tire softener is a solvent that breaks up the
> long-chains, mostly on or near the surface.
>
> This solvent has no water, so should not even be aware
> of ambient water vapor levels (humidity). I.E.,
> humidity shouldn't delay solvent evaporation. I have
> seen reference to shrink-wrapping tires as part of the
> softening process, but know no details.
>
> But as to your thumbnail tests, I use a durometer. And
> I've found the hardness is very temperature dependent.
> New slicks in the cold garage test much harder than
> my street tires in the driveway. Could your thumbnail
> results actually be reflecting temperature?
>
> -- Bill
>
> --- KWall73108@aol.com wrote:
> >The following leads me to believe that humidity
> >plays a large role in a
> >competition tire's useful life.
> >
> >Before treating slicks with Formula V a thumbnail
> >test is done to check the
> >rubber's softness. For the first two autox's of
> >this year the rubber was
> >extremely hard before applying FV. The rubber
> >hardness' of the first test can be
> >understood because the slicks sat idle for over a
> >year. On that first occasion
> >the slicks softened up with FV and gripped beyond
> >expectations. Again, the
> >rubber was really hard before the FV treating for
> >the second event and again
> >softened up with FV to grip beyond expectations.
> >
> >When the slicks were just thumbnail tested before
> >this week's treatment the
> >rubber was suprisingly soft. Since it has been
> >raining for the four days
> >following the last autox it appears the softening
> >agent in the rubber hasn't been
> >allowed to evaporate to the extent it did in a dry
> >climate.
> >
> >Since FV has been used for the past five years with
> >the typical rubber
> >hardening over a weeks time before the next
> >treatment, the FV retention via humidity
> >appears logical.
> >Has anyone tried keeping their competition tires in
> >a high humidity
> >environment between events, if so, what effect did
> >that have? Would it make sense to
> >add increasing amounts of FV to that high humidity
> >environment as the tire got
> >used up?
> >
> >Kevin Wallace
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