Yet another approach I have used is to take 3-5 gallons of water and add
LOTS of DARK food coloring. Pour it in the tank along with a teaspoon of
detergent. The detergent is to act as a surfactant and allow for less
surface tension. Seal up the wing (cap) and pressurize the tank to 1-2
PSI. You can then prop the wing up leading edge down and see what you get.
If the leak is around the main spar you'll see the blue flow. If you
loose all your pressure and no blue... flip the wing leading edge up and
try again. As you move the wing around from leading edge up to down,
upright to inverted, wing tip down to wing tip up, etc. you can isolate
where it is by identifying where you loose air pressure without any flow of
liquid. I found 2 leaks this way in about 30 minutes. The volume of fluid
can be adjusted down depending on the tank size. This worked for me, hope
it helps!
Rick Muller
SR70
-----Original Message-----
From: phil stubley [SMTP:
phil.stubley@sympatico.ca]
Sent: Thursday, May 02, 2002 9:27 AM
To:
murphy-rebel@dcsol.com
Subject: Re: DIGEST - murphy-rebel-d
From:
rebaker@ftc-i.net
To: murphy-rebel-d
Subject: fuel tank leaks
Wayne,
You say you always fix leaks from the outside and we did two gushers that
way by cutting a handhole behind the rear bulkheads in our Elite. We
have
an elusive small leak remaining. We have soapy water tested the top an
bottom skins, fuel cap, root rib, and all the fittings with no resulting
bubbles. Have used a modified stethoscope to listen as far as possible
through handholes with no joy. It seems the leaks must be at the main
spar, outboard solid rib, or possibly rear bulkheads.
Two questions:
Any suggestions as to how to locate these internal leaks without just
blindly cutting?
How do you deal with access to leaks at the main spar area? Do you cut
the
leading edge skin?
Additional suggestions solicited from all sources.
Thanks,
Ralph Baker
***Ralph
Had a similar problem. Fixed what appeared to be a leak from the upper
outboard stringer region, but a small weep still remained. Have three
holes in the lower skin, two behind and one outboard of the tank, and
did all kinds of searches, (except the stethoscope. Not enough pressure
to get a sound.) Best method was small pieces of paper towel at each
suspect location, after drying out the area, and leaving for a few
minutes. Wetness showed right away, (minutes) but needed several tries
to confirm the location. Then tried to fix the area, which was on the
rear bulkhead top. After several tries, I gave up, removed the wing,
sloshed it ( against my better judgment) and now it's dry.
Incidently, this leak was not there initially. It appeared after the
second winter, so something moved I suspect due to temperature
variations.
And Wayne's comment about checking for SIMPLE causes is a good one.
After the fix was satisfactory I was happy until it started to leak
AGAIN, with vengeance this time. I swore a few times, (many actually)
and finally got mad enought to remove the fairings, and found that I had
not assembled the outlet fitting properly, the pipe clamp was not
correctly placed. So that part I fixed in a few minutes. What a
relief!!!
Good luck with it.
Phil.
R302, 5 years flying.
*-------------------------------------------------------------------------*
To unsubscribe go to
http://www.dcsol.com:81/public/listserv.htm
Archives located at
http://rebel:builder@www.dcsol.com:81/default.htm
To contact the list admin, e-mail
mike.davis@dcsol.com
*-------------------------------------------------------------------------*
*** File "WINMAIL.DAT" has been uudecoded and attached to this message.
-----------------------------------------------------------------
List archives located at:
https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe:
rebel-builders-unsubscribe@dcsol.com
List administrator:
mike.davis@dcsol.com
-----------------------------------------------------------------
