Message-ID: <000701be54c6$5cedd1e0$5b06ffd0@oemcomputer>
From: "bobjude" <bobjude@gateway.net>
To: "Lancair Mail List" <lancair.list@olsusa.com>
Subject: Fuel leaks and Heat Wrap
Date: Wed, 10 Feb 1999 01:24:12 -0600
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
Jim Solensky:  I had a very small leak in my left wing tank that showed up
after about 50 hours.  If I put in 15 gallons there was no leak (on the
ground).  If I put in 16 gallons and parked it,  I would see blue stains at
the wing/stub wing interface, bottom TE.  No drips, just stains.  After the
hanger collapsed on my airplane the wings were removed so I had an
opportunity to find and repair the leak.  It was at the top of the aluminum
tube that provides the path for aileron push rod.  I didn't think that I
would ever have a problem with all that tank sealer but apparently through
temperature cycling  and normal flight stresses, a small leak did develope.
I used the recommended repair method of pulling a vacuum on the tank and
applying warm epoxy  for a while, then cooler epoxy  and removing the vacuum
while the epoxy cured.  Since my leak was at the aluminum to fiberglass
interface, I took the additional step of saturating some fiberglass with
Hysol adhesive and laying it over the junction where the leak was.  I used
Hysol here instead of epoxy because it sticks better to aluminum.

Tom Giddings:  I put my heat wrap on after about 100 hours.  There was a
significant rise in indicated EGT.  Initially I was runninig near the middle
of the recommended range.  (I don't remember the numbers)  After applying
heat wrap the EGT was running near the high end.  I was worried about it
first but after discussion and consultation with others using heat wrap,  I
am convinced that the rise in indicated temp. does not necessarily mean that
the EGT has actually gone up that much.  The instrument responds to probe
temperature which is not the same as gas temperature.  Since the probe
conducts heat to the exhaust pipe, the temperature of the pipe has a lot to
do with indicated EGT.  Obviously the ehaust pipe will run hotter when it is
covered with heat wrap hence the higher indicated EGT.

Bob Jude
N65BJ