Fuel Tanks
Included in the kit is a pair of moulded fibreglass fuel tanks, each holding about 800cc, that fit into
the wings very close to the Centre of Gravity - therefore giving minimal trim change during flight.
They have internal baffles in-
stalled during manufacture, to
prevent fuel surge. A moulded
fibreglass tube (17mm I.D) is
bonded into the top of each
tank, and this accepts standard
sized stoppers (eg: Dubro or
Sullivan). The plastic top and
bottom plates, and connecting
screw, for the stoppers are in-
cluded in the kit, but you need
to provide the brass tubes (1/8”
dia.), kerosene compatible
stoppers (eg: Dubro pt. #400),
Tygon tubing and clunks.
All tanks are tested at the fac-
tory for leaks, but of course it is
wise for you to double-check
them before installing in your
plane !
Please wash out the fuel tanks
before fitting the stoppers, to
make sure there is no dirt inside that could get into the
turbine fuel system. We use petrol/gasoline for washing
tanks out, and then discard it afterwards.
Make up the stoppers, bending the brass tubes that will
be inside the tank, as shown. Because of the angle of
the stopper tube you will need to bend the vent/over-
flow brass tube at least 90°, and then extend it with a
short length of Tygon so that it fully reaches the top sur-
face of the tank and allows you to fill it completely. Make
sure that the clunk weights do not quite touch the in-
ternal baffle in any position.
We recommend that you either solder on proprietary
‘fuel barbs’, such as the Dubro ones shown, or very
short lengths of 1/8” I.D brass tubing to make sure that
the fuel tube cannot slide of the the Ø 1/8” brass feed
tubes - or have any chance of an air leak.
Install both completed, and leak-tested, tanks in the
wing roots. Lightly sand the milled balsa/glass ribs so
that they fit neatly into the wing roots to hold the tanks
in place. Glue these in place only with a very little sili-
cone, so that you can easily remove them if needed maintenance.
Fox Composites Co., Ltd.
14
(above) The moulded wing tanks are included in the kit, as
well as basic stopper hardware. You can bend brass tubing
without kinking it using the bending springs available from
K&S (shown). Also shown is a completed stopper assembly.
(below) Solder ‘fuel barbs’, or short lengths of larger tubing,
over the brass feed tubes to prevent air leaks and stop the
fuel tube sliding off.