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page was updated on
03/04/2010
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Fuel Tank Installation |
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| 7/5/06- I hung my
fuel tank from some clothesline to get an idea of how it fits.
It is a very tight fit between the tubing that goes from 0-0 to 30
so right now the rear of the tank is 1 degree higher than the front.
I would raise the front a bit, but it might not clear the front
cabanes so I'm going to install the cabanes before finishing the
tank installation. |
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| 7/5/06- To install
the tank mount bushings, drilled 1/4" holes spaced 2" apart in a 2x4
and bolted the bushings to it. |
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| 7/5/06- Then I
clamped the 2x4 in the proper position on the longeron. |
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| 7/5/06- Finally, I
tack welded the bushings in place. |
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| 8/1/06- The
tank just doesn't fit properly because the interior tubes that mount
from 0-0 to 0-24 are located a bit too far inboard. I'm going
to have to cut the 2 tubes out and re-weld them once the fuel tank
is installed. |
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| 9/1/08- Here are the
parts for 1 of 2 of my fuel valves. The handles came off a
Stearman. |
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| 9/20/08- The fuel
valve linkages are done. The top valve is for the upper wing tank,
the bottom valve for the main tank. The top tank drains into
the main tank. |
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| 10/22/08- After
practice building 3 smoke tanks (the last one was a keeper), it's
time to build the fuel tank. The design I'm using has an upper
and lower compartment with a flop tube in the lower compartment for
inverted flight. The tank is built in 2 sections. In
this picture, I've bent the lower corners of the upper compartment.
Next, I have to bolt the 4 formers together using the threaded rod. |
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| 10/23/08- I
evenly spaced and bolted together the 4 formers, then bent the
aluminum around the formers using cinch straps. The 1x2's
under the straps are needed to make the aluminum lie flat against
the straight surfaces. |
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| 10/25/08- After
letting the aluminum take a 'set' overnight, I unbolted 3 of the
formers, placing them evenly inside the aluminum tank wrapper.
If you don't take the bolts out of the formers, you will never get
the formers out of the wrapper without damaging it. The loose
formers can easily be tapped askew and removed. |
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| 10/25/08- Here
is a top view of the top compartment wrapper. Notice that I
left the protective film in place while clamping and welding. |
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| 10/26/08- After
popping the formers out of the tank wrapper, I trimmed .050" all the
way around one former and 3/8" around a second former. The
larger former is used to form the end panel around while the smaller
former is used as the clamping plate. In this picture bent the
bottom flange on my break and just started bending the top and side
flanges with my mallet. I then took the panel out of the
formers and used my shrinker to shrink the top flange. Just
don't shrink it too much or it will really deform the panel. |
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| 10/26/08- I had to
cut pie shaped pieces from the upper corners to make the metal lie
down around the sharp radius. |
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| 11/2/08- I bent the
bottom sump wrapper on my brake and then formed the end panels over
forming blocks. |
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| 11/2/08- Once the
upper wrapper was tack welded and the inside formers removed, the
wrapper lost some of its shape. I still needed to install the
baffles and end panels so I cut 2 female formers to hold the
wrapper's shape. |
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| 11/2/08- The
outside formers are simply clamped together using 2 cinch straps.
The baffles are not riveted in place yet, just checking for fit. |
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| 11/2/08- The
outside formers also allowed me to insert shims to get a perfect
seam along the end panels for welding. I leave the protective
plastic on until I absolutely have to remove it. |
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| 11/20/08- Here I've
cut the vent holes in the tank and bent the vent and inverted vent
lines and welded them to their 1/8" NPT bungs. |
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| 11/20/08- You can see
the vent tubes sticking out of the bottom of the upper compartment.
I have 4 holes in the front panel. They are for the fuel
transfer line from the wing tank (1/4"), vent line (1/8", inverted
vent line (1/8"), fuel return line (1/8"). If I don't need the
fuel return line, I'll just put a plug in it. |
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| 11/20/08- An
inside view of the baffles and the vent lines from the rear of the
tank. There is a #40 hole drilled at the top of the vent lines
for an anti-siphon. |
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| 11/20/08- The inside
of the upper compartment and the rear panel with the fuel sender
hole cut out. |
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| 11/20/08- Instead of
pop rivets, I used 3/16" x 5/16" structural rivets to make sure that
the baffles never come loose. (AN 426AD-6-5) |
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| 11/20/08- I used the
driven rivets on the top and bottom and 3/16" pop rivets on the
front and rear panels. Here, you can see the bottom sump being
fitted to the top. |
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| 11/20/08- The front
panel of the bottom sump is notched so that the standpipe and the
vent tubes clear the flange on the panel. Notice that unlike
the Mackenzie plans, I placed my standpipe and flop tube mount at
the front of the tank rather than the rear. I made the change
because I could envision that at a very high angle of attack, like
anything between 60 and 90 deg with 1/2 tank of fuel, would cause
the fuel in the sump to run back out the standpipe and uncover the
flop tube pickup at the front of the tank. |
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| 11/20/08- Here is the
rear view of the 2 compartments not yet welded together. |
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| 11/22/08- This is the
bottom of the upper tank compartment. You can see the
standpipe, inverted vent, and upright vent. Notice that I used
3/16 x 5/32 rivets to fasten the baffles to the bottom. There
is also a patch plate to the left to cover my first standpipe hole
that would not allow the standpipe to clear the bottom side of the
sump. If you look closely, you can see the #30 pilot holes
drilled around the perimeter to rivet the bottom sump. |
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| 11/22/08- After back
drilling down through the sump flanges, it is now clecoed in place.
I used 1/8" pop rivets spaced every 2". If I had made the sump
flange 1/2" wide instead of 1/4" as called out in the plans, I could
have used 3/16" rivets for extra strength. But the 1/8" rivets
pulled it all together nicely anyway. |
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| 11/22/08- The front
of the tank is tack welded. I still used my cinch strap and
shim blocks to bring the sides up tight. |
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| 11/22/08- The
rear of the tank is tack welded. I used 3/16" pop rivets to
fasten the baffles to the rear panel just like the front. |
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| 11/24/08-
Finish welding the tank seams. The recycle bin was perfect for
holding the tank in a perfect position. |
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| 1/2/09- The
rear view of the tank shows the fuel level sender. The jigs on
top are for setting the tank at the proper height. |
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| 1/2/09- I bent
and welded up the strap brackets out of some scrap 4130 and riveted
them to the stainless .035 x 1" straps. You need 4' for each
strap. |
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| 1/2/09- Since
the tank was now completed, I reinstalled the 0-24 tubes to give me
about 3/8" clearance between the straps and the tubes. |
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| 1/2/09- The tank
height can be adjusted about 3/8" both ways. |
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| 1/2/09- At the plans
height, the top sheet metal will clear the tank by about 1/4" at the
firewall. That is my firewall template clamped in place. |
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