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Hi Al, I don't know if this has any relevance to your problem or not, but
about a year ago some fuel that came from the Thorton chain around our
area was eating up fuel senders. Several people I know had this problem,
Thorton's took care of replacing I don't know how many senders. What I
heard was there was an extremly high sulphur content in the fuel that was
attacking the senders. I don't know if this is related to your problem or
not, but I would drain the fuel and see if someone in your area might be
able to test a sample of it to see what it has in it. Fred
At 10:14 AM 7/31/2006 -0700, you wrote:
Not
sure where to go with this because there are only a few here with epoxy
fuel tanks, and on the Velocity list very few interested in the use of
mogas. I’m suspecting fuel compatibility isses.
I first put fuel in the tanks nearly 2 years ago and used Chevron
regular. Everything was fine. When I moved the plane to the airport
3 months ago (tanks empty) I filled with Exxon-Mobile. Four
troubling things have come up in the past few weeks.
- I have Vance Atkinson site gauge that has a white plastic back plate
for easier reading of the fuel level. The small hole through the backing
has been swelling shut so the sight gauge no longer works. I contacted
Vance who said that there are hundreds of these gauges in EZs using mogas
without problems, but he has had 3 incidents like mine in the last three
months.
- A couple of weeks ago there was suddenly a pinhole leak in one of the
gear well enclosures. These enclosures are part of the fuel tank
wall, and are parts that come with the Velocity kit. These are also
made and coated with EZ-poxy.
Looking in through the filler cap I see
reddish-purple splotches and streaks on those gear leg enclosures.
Poking and scratching with some safety wire on a stick does not indicate
any softness of the surface.
Yesterday, under the leading edges of one
of the strakes, I noted an area with some slight surface
irregularity. Pushing on it suggests some sponginess. This is
½” foam core material, and indicates the possibility of a pinhole leak in
the inner skin, and fuel softening the PVC foam. PVC foam is
supposed to be unaffected by fuel.
My tanks (strakes) were made and coated with EZ-poxy back in 1998.
At the time I polled EZ flyers about there experience, and talked to reps
of various epoxy manufacturers about auto fuel compatibility. All
the evidence said go with the EZ-poxy.
Any others with composite tanks having any trouble? Anybody using
Exxon-mobile fuel? Know of any new additives that are an
issue?
I’m thinking I should drain this fuel ASAP, but then what? Other
brand? That expensive Avgas? Regardless I may be faced with
cutting open a strake at some point, but right now we are trying to get
first flight done this coming weekend.
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