R22 Discussion Group

On Jul 12, 2020, at 9:49 AM, Sling via Rhodes22-list <rhodes22-list at rhodes22.org> wrote:

Hi Jessie,

While getting the weight off the trailer wheels in the winter and covering them with tire covers to limit UV exposure will both help extend trailer tire life, unfortunately the big tire killer is oxygen exposure.  Oxygen is the 2nd most reactive element (behind fluorine) and the rubber polymer chains in the tires are vulnerable to its effects.  One other thing you can do is fill your tires with nitrogen or argon vs. air.  Yes, I know this sounds silly.  But, oxygen degradation is a diffusion limited process.  All else being equal, having an inert gas inflating the interior of the tire will slow down the diffusion rate by a factor of at least 4X due to switching oxygen diffusion from a 2-way process (outside in + inside out) to 1-way (outside in only).  Actually, the inert gas may extend the tire’s life even more because the elevated oxygen partial pressure inside the tire increases the diffusion driving force favoring oxygen diffusion into the tire from the inside out by the ratio of the [absolute inflation air oxygen pressure psia]/[absolute ambient oxygen partial pressure].  For example, suppose you inflate your tires to 40 psi (40 + 14.7 = 54.7 psia).  Air contains ~21%vol oxygen.  So, the partial pressure of oxygen in the ambient air is 0.21 * 14.7 psia = 3.09 psia.  The partial pressure of oxygen inside your tires is 0.21 * 54.7 psia = 11.5 psia.  11.5 psia / 3.09 psia = 3.7 X times more diffusion driving force for oxygen from the inside out when the tire is inflated with air.  I would recommend nitrogen vs. argon because it’s cheaper and the thermal conductivity is about the same as air.  The thermal conductivity of argon is ~40% less than air, which will cause the tire to run somewhat hotter on the road, which is not good for tire life.  But, this is not a big factor.

Roger Pihlaja
S/V Dynamic Equilibrium

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From: ROGER PIHLAJA<mailto:roger_pihlaja at msn.com>
Sent: Sunday, July 12, 2020 11:53 AM
To: daysails at aol.com<mailto:daysails at aol.com>; The Rhodes 22 Email List<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Getting the weight off the tires for winter storage

Hi Jessie,

Yes, having the rear jacks will absolutely stop accumulated water in the stern from causing the bow to rise up.  It also allows you to have as many people in the cockpit as you wish when you are camping.

Unfortunately, a lot of my Rhodes 22 cruising gear is locked up and inaccessible at Johnson Mini Storage.  MDOT is working on putting in a temporary M-30 bridge over the Tittabawassee River in Edenville.  However, they must first clear the debris from the river channel.  This includes the pieces of the Wixom Dam powerhouse, turbines, and generators.  MDOT crews have built a wier just downstream of the wrecked M-30 bridge.  This wier restricts the flow of the river upstream of the bridge and makes it deep enough for a work barge.  The work barge is gathering debris from the river channel and stacking it on the south river bank.  On shore, another tracked vehicle with a hydraulic claw is scooping up the debris and loading it into dump trucks.  I’m sure they will remove the wier when the job is finished.  However, right now there is a class 3 waterfall/rapids where the river spills over the wier.  The work barge is operating < 100 yds upstream of the wier.   So, it’s very dangerous work.

MDOT’s crystal ball is calling for the temporary M-30 bridge to be in place by early October.  I will have no access to Johnson Mini Storage before then.  We have no cruise planned on S/V Dynamic Equilibium this year because so much of my gear is locked away.  However, in August, I have two water related adventures planned.  I am going to lead my Boy Scout Troop on a High Adventure shipwreck SCUBA diving trip in the Straits of Mackinac.  Then, later in the month, my two sons, my brother-in-law, and I are going to attempt a west to east voyage on Lake Superior thru the Pictured Rocks National Lakeshore from Munising, MI to Grand Marais, MI by sea kayak.  This will be a 4 day, 3 night trip along one the most exposed stretches of Lake Superior coastline!

Other than that, my summer is dull!

Roger Pihlaja
S/V Dynamic Equilibrium

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ROGER PIHLAJA

Getting the weight off the tires for winter storage