Fuel Drip Containment

"C J Campbell" wrote in message
...
Don't fill your plane before putting it away?

We turn the fuel valve off or turn it to left or right tank -- this seems
to
mitigate the problem considerably, though I am not sure why it does this.

Because in any position besides the BOTH setting, it prevents fuel from
flowing between the tanks... or more precisely, from the (slightly) upper
tank to the lower tank and out the lower tank's fuel vent.

Eric

"Eric Miller" wrote in message
...
| "C J Campbell" wrote in message
| ...
| Don't fill your plane before putting it away?
|
| We turn the fuel valve off or turn it to left or right tank -- this
seems
| to
| mitigate the problem considerably, though I am not sure why it does
this.
|
| Because in any position besides the BOTH setting, it prevents fuel from
| flowing between the tanks... or more precisely, from the (slightly) upper
| tank to the lower tank and out the lower tank's fuel vent.
|

Okay, that much I knew, but why doesn't the lower tank just empty itself?
Does it need the pressure from the higher tank in order to start siphoning
out the fuel vent?

Sporty's oil mat #8667A might work, but I use an open gasoline can on the
floor. There's usually not much wind in a hangar, so the drips will go right
in once it is positioned. The small opening in the can reduces the amount of
evaporation you would get compared to a mat or just letting it hit the
floor.
Afterward, I use the fuel to run my lawnmower.

"C J Campbell" wrote
Okay, that much I knew, but why doesn't the lower tank just empty itself?
Does it need the pressure from the higher tank in order to start siphoning
out the fuel vent?

I think the lower tank does empty itself... but just until it gets to the
level of the fuel vent.
In the BOTH setting, they'll both empty to the level of their respective
vents.
Keep in mind that the right tank is vented to the left tank, and the left
tank is vented overboard, so if possible, it might help to make the right
tank the lower one.

Eric

C J Campbell wrote:

Okay, that much I knew, but why doesn't the lower tank just empty itself?
Does it need the pressure from the higher tank in order to start siphoning
out the fuel vent?

It doesn't siphon, it flows. Without the fuel from the other tank it
can't flow.

Eric Miller wrote:


I think the lower tank does empty itself... but just until it gets to the
level of the fuel vent.
In the BOTH setting, they'll both empty to the level of their respective
vents.

There is only one vent, under the left wing. If fuel expands it runs in
a line between the left and right tanks. This line is above the tanks.
Fuel will also go thru this line if the selector is on both, the tanks
are full or near full and the plane is not level. Move the selector to
either right or left and this won't happen. If left on both the tanks
will level themselves thru the selector.

****There is only one vent, under the left wing*****

Not on my high wing Cessna. There are vents behind the struts for both
wings.

Karl
"Curator" N185KG

"Newps" wrote in message
news:KXRmb.34654$Tr4.62408@attbi_s03...


Eric Miller wrote:


I think the lower tank does empty itself... but just until it gets to
the
level of the fuel vent.
In the BOTH setting, they'll both empty to the level of their respective
vents.

There is only one vent, under the left wing. If fuel expands it runs in
a line between the left and right tanks. This line is above the tanks.
Fuel will also go thru this line if the selector is on both, the tanks
are full or near full and the plane is not level. Move the selector to
either right or left and this won't happen. If left on both the tanks
will level themselves thru the selector.

"karl gruber" wrote in message
...
****There is only one vent, under the left wing*****

Not on my high wing Cessna. There are vents behind the struts for both
wings.

Karl
"Curator" N185KG

What model?

The 172S has the left tank vented behind the wing strut and right tank
vented to left tank.
The 172M has the left tank vented behind the wing strut and right tank
vented through the fuel cap.
Both according to the respective POH (and backed up by memory).

Of course, Cessna makes other models too, some of which aren't even 172's!

Eric

Eric Miller wrote:

Of course, Cessna makes other models too, some of which aren't even 172's!

And, in fact, the aircraft in the intital post of this thread is an elderly
182.

George Patterson
You can dress a hog in a tuxedo, but he still wants to roll in the mud.

Not an acceptable fix. Liquid fuel in an open container is not where I wanted
to go. I could just have used a bucket on the floor instead of taking a chance
on bending the vent with a quart (1½ #) of fuel hanging on the line.

But thanks for trying.



"Sven"
shared these priceless pearls of wisdom:

-Hi Jim,
-
- I have seen people hang an empty plastic oil bottle on the fuel vent to
-catch the dripping fuel on Cessnas. Have you tried this? It shouldn't be too
-much of a fire hazard and will save your hangar floor. Just make sure that
-you drain the bottle regularly because the angle it sits on the vent, it
-won't hold a whole quart of fuel. Using a GATT jar or some other filter, you
-can reuse the fuel.
-
-"Jim Weir" wrote in message
.. .
- Snarly Charlie, the 182, has the classic "Cessna drip" from the fuel vent
-when
- the tanks are filled and the hangar gets warm. I've tried everything I
-know to
- stop it, but all I can do with all the mechanical fixes is slow it down.
-

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com