REFLECTOR:fuel tank leak testing
Ronnie Brown
reflector@tvbf.org
Sat, 5 Jul 2003 13:42:02 -0400
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I would suggest lowering the pressure to nearly nothing - perhaps have a =
friend blow into the hose, while you spray with dish detergent/water =
solution. You should be able to make some good bubbles. If you use too =
much pressure/flow, the bubbles will just burst before you can see them.
Then as Dave Black suggests, make sure you pull a vacuum on the tank =
(again a friend) while applying the epoxy. It really needs to flow into =
the leak to be effective. If you just brush the surface you will get a =
pretty light coating which can easily rupture. The flow into the crack =
should be short. Don't suck it all the way into the tank.
And be very careful about how much pressure you are putting on the tank =
- no more than 1/2 to 3/4 psi. A good way to measure this is with a U =
tube manometer made with 1/4 or 3/8 tubing. One end of the U tube =
should be open. The other end connects to a tee. The one leg of the =
tee connects to the tank, the other connects to a valve and hose that =
you blow or suck depending on what you need. Each leg of the U needs to =
go up at least 2 to 3 feet. Then by sucking or blowing, you can create =
a differential water level of 12-18" of water.
Good luck - don't give up - this has happened to a lots of folks!
Ronnie Brown
----- Original Message -----=20
From: dean fitzbag=20
To: reflector=20
Sent: Saturday, July 05, 2003 1:01 PM
Subject: REFLECTOR:fuel tank leak testing
I'm still having difficulty finding and eliminating my fuel tank =
leaks. Let me review what I have done.
My two small bulkheads between the large rear bulkhead and the main =
spar have already been installed, but I can get my hand through the =
opening.
I reduce the pressure on my air tank/pump to a few psi (so I can =
easily stop the flow with my finger) so as to not damage the tank. I =
can hear the air escaping from behind the large bulkhead. When I first =
began working on it, I could feel air coming from that area just by =
reaching my hand in there. I have used a soapy solution, but cannot see =
any bubbles. I have used this technique with tires before with good =
results. However, the pressure in those cases were over 30psi.
I then tried using the tubing as some of you suggested. The sound is =
not localized and seems to be very steady all along the rear bulkhead.
I have applied sealant all along the seam using a paint brush attached =
to a pair of sticks so that I can adjust the paint brush after getting =
it through the small bulkheads.
It is hard to tell without quantitative measurement, but I think it is =
improving some.
I also tried to spray epoxy in the cavity using a water sprayer. The =
epoxy and cabasil were too think to really spray.
Any help would be appreciated.
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<DIV><FONT face=3DArial>I would suggest lowering the pressure to nearly =
nothing -=20
perhaps have a friend blow into the hose, while you spray with dish =
detergent/water solution. You should be able to make some good =
bubbles. If=20
you use too much pressure/flow, the bubbles will just burst before you =
can see=20
them.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>Then as Dave Black suggests, make sure you pull =
a vacuum=20
on the tank (again a friend) while applying the epoxy. It really needs =
to flow=20
into the leak to be effective. If you just brush the surface you =
will get=20
a pretty light coating which can easily rupture. The flow into the =
crack=20
should be short. Don't suck it all the way into the =
tank.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>And be very careful about how much pressure you =
are=20
putting on the tank - no more than 1/2 to 3/4 psi. A good way to =
measure=20
this is with a U tube manometer made with 1/4 or 3/8 tubing. One =
end of=20
the U tube should be open. The other end connects to a tee. =
The one=20
leg of the tee connects to the tank, the other connects to a valve and =
hose that=20
you blow or suck depending on what you need. Each leg of the U =
needs to go=20
up at least 2 to 3 feet. Then by sucking or blowing, you can =
create a=20
differential water level of 12-18" of water.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>Good luck - don't give up - this has happened to =
a lots of=20
folks!</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>Ronnie Brown</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Ddfitzbag@msn.com href=3D"mailto:dfitzbag@msn.com">dean =
fitzbag</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, July 05, 2003 =
1:01=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> REFLECTOR:fuel tank =
leak=20
testing</DIV>
<DIV><BR></DIV>
<DIV>I'm still having difficulty finding and eliminating my fuel tank=20
leaks. Let me review what I have done.</DIV>
<DIV> </DIV>
<DIV>My two small bulkheads between the large rear bulkhead and the =
main spar=20
have already been installed, but I can get my hand through the =
opening.</DIV>
<DIV> </DIV>
<DIV>I reduce the pressure on my air tank/pump to a few psi (so I can =
easily=20
stop the flow with my finger) so as to not damage the tank. I =
can hear=20
the air escaping from behind the large bulkhead. When I first =
began=20
working on it, I could feel air coming from that area just by reaching =
my hand=20
in there. I have used a soapy solution, but cannot see any=20
bubbles. I have used this technique with tires before with =
good=20
results. However, the pressure in those cases were over =
30psi.</DIV>
<DIV> </DIV>
<DIV>I then tried using the tubing as some of you suggested. The =
sound=20
is not localized and seems to be very steady all along the rear=20
bulkhead.</DIV>
<DIV> </DIV>
<DIV>I have applied sealant all along the seam using a paint brush =
attached to=20
a pair of sticks so that I can adjust the paint brush after =
getting it=20
through the small bulkheads.</DIV>
<DIV> </DIV>
<DIV>It is hard to tell without quantitative measurement, but I think =
it is=20
improving some.</DIV>
<DIV> </DIV>
<DIV>I also tried to spray epoxy in the cavity using a water =
sprayer. =20
The epoxy and cabasil were too think to really spray.</DIV>
<DIV> </DIV>
<DIV>Any help would be appreciated.</DIV></BLOCKQUOTE></BODY></HTML>
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