Prepare the tank
stiffeners. This involves a lot of scoring of surfaces to which gas tank
sealant must adhere.
|
Have a local qualified
QCR (Quality Control Rodent) inspect the stiffeners.
|
Apparently this part
passed inspection.
|
Take a soldering iron to
the inside of the tanks to remove enough of the blue vinyl for the
stiffeners.
|
Remove enough vinyl on
the outside of the skins as well.
|
Dimple all holes that
can be dimpled.
|
Score the inside surfaces where
the stiffeners will go. We chose to use carborundum (ruby.)
|
After mixing and applying
sealant to both the inside surfaces AND the stiffeners, cleco in place and
back-rivet them in. It is very beneficial to line up stiffeners in the
exact order ahead of time as they are of different lenghts. The sealant
doesn't wait for you while you figure it out.
|
Wipe off excess sealant.
|
Give all edges a good
bead of sealant and all rivet heads a second coat.
|
What a mess!
|
Keeping the blue vinyl
on until the sealing was done kept the inside of the skin in good shape
(this changes when we put the ribs in, we assure you!)
|
All tank rib flanges
must also be scored in order for the sealant to grip. We found a paint
stripping wheel to work very well for this purpose.
|
Clean all ribs really,
really well and handle only with gloves. Otherwise dirt or skin oils could
compromise the adherence of the sealant to the metal.
|
Cleco all ribs in place.
|
Mix the sealant. We
found that if we used 0.25 oz of the black and 2.5 oz of the white that we
had enough to seal two ribs.
|
A little removeable tape
(masking or electrical) around the inside of the rib helps to keep the
mess under control.
|
Apply sealant to the
tank rib flanges.
|
Apply sealant also to
the mating surface on the inside wing skin. We preferred to use plastic
knives over popsicle sticks.
|
Pick out a hole to be
riveted.
|
Apply sealant to the
hole and put in a rivet.
|
Push the rivet in place.
|
Wipe off excess oozing
sealant to prevent the rivet gun from getting too dirty.
|
Rivet in place (we
always had one person holding the bucking bar(s) while the other one shot
the rivet gun.)
|
Bottom view - the four
middle ribs are done!
|
Top view.
|
Double checking the
rivets here is critical. Bad rivets will happen, and it's better to catch
them while you still have enough sealant mixed for a couple of re-do's.
|
Capacitive fuel senders
are getting installed.
|
We fished a metal rod
through one side, wrapping the white wire around it. Then from the other
side we pushed the vent tube over the metal rod but inside the coils of
white wire.
|
The tanks are now ready
for the last rib (outboard) to be put in. This job requires the same tools
as before but uses the rivet squeezer in place of the rivet gun (for most
of the rivets.)
|
After both surfaces
(inside the tank and rib flanges) were adequately buttered with sealant
(or is it just Nutella?) one of us stragegically placed the rib while the
other made sure the capacitive fuel sender wire was adequately wound
around the tube. You only get one chance to make sure you have it correct.
|
The rivets around the
edge of the last rib are complete (the few around the blue vent tube
connector and the bnc connector required the rivet gun as the squeezer
would not fit.
|
The tank reinforcement
plates are next to be riveted on.
|
|
|
|
|
|
|
That's one less shirt to
wash.
|
"And
for this airplane-to-be, let us give tanks...."
|
With the exception of
the baffles, these tanks are just about done. It would, perhaps, be a good
time to get the insides inspected first.
|