Tuesday, May 21, 2013

Section 16 -- Fuel Tanks -- Continues

Build Hours Added Since Last Post:19.25

When I last posted, I had commenced the daunting task of building the fuel tanks.  While I would not yet classify myself as a seasoned expert in the ways of Pro Seal, I have gained enough experience to declare it nasty work.

With the prep work out of the way and the only thing left to do is rivet the parts together, I started with the ribs.  It's a fairly straight-forward proposition.  Simply mix the two parts of the Pro Seal, spread a layer on the skin like frosting a cake (a sticky and stinky frosting), slide the rib in place, cleco it, and bang away.  Unfortunately for me, it's much less romantic than it sounds--and it doesn't sound romantic at all, I suspect.

Left wing skin all ready for action
You may note from these two pictures that the ribs seemed to magically appear in two shots.  Well, the real story is that it took days to get to this point and I wasn't prepared to risk Pro Sealing my phone/camera to get nice shots along the way.  The process will just need to remain a mystery that those uninitiated few.

Ribs, vent line, fuel cap, J-channel, lower supports, and drain connection in place
Fuel vent line shown, but not connected

Open end of the vent line near the fuel cap (otherwise known as the money hole).
Fuselage brace in place.  Awaiting fuel float and fuel lines
Left fuel tank all ready for the next steps

The remaining components of Section 16 include the fuel floats/sender, fuel lines, connection nutplates, attachment of the rear baffle, and testing. Yay

Sunday, May 12, 2013

Section 16, Fuel Tanks

Build Hours Added Since Last Post: 27.5

Anyone following my blog may have noticed that I haven't updated it in nearly three weeks.  Rest assured that work continues and that I have put in about 27 hours since my last post.  My seemingly quick progress with the wings has slowed to an extremely slow pace since I started the fuel tanks.  I'll admit that I have not pushed as much to get through this section as I have with other sections, but with a little Pro Seal experience under my belt, I'm more confident that the tanks will be done soon enough.  For those of you that don't know, the RV-14 (and I think all RV models) use a "wet wing" whereby the inboard leading edges of each wing are the fuel tanks.  So the fuel is simple poured into the wing instead of a bladder or other fuel tank.  Therefore, in order to keep the fuel from leaking out of every rivet, seam, or other hole, the manual calls for Pro Seal to be used wherever needed.  By its very nature, Pro Seal is by all accounts nasty material.  It seems to get on everything and has the stickiness of honey.  Thankfully, it cleans up nicely with MEK--of course, MEK is another nasty chemical.

In order to prep everything for the fuel tank, it's back to the same thing again--i.e., fluting, final drilling, deburring, and dimpling each wing rib.  For the fuel tank components, I purchased a fuel tank dimple die set.  These dies dimple the skins and structural components slightly deeper than the standard die to create a smoother look when the Pro Seal is squeezed in between the parts.

Fuel Tank Parts
Tanks Stiffeners for the Bottom Portion of Each Tank
Match drilling the J-stiffener for the top of the fuel tank skins

Left wing fuel tank skin with some ribs cleco-ed in place.  You can also see the Zee tank connectors primed with nutplates installed.

Right wing fuel skin with rear baffle cleco-ed in place

Dimpling the fuel tank skins on the C-frame using the fuel tank dimple die set.

These are the fuel cap receptacles.  They have a really nice anodized red color.  Too bad they will never bee seen once in place.  Here, one is countersunk and the other is in its "raw" form.
These are the brackets that will connect to the wing root.  They are ready for priming.

Here is a completed bracket.  Note that because half of the bracket sits inside of the tank, only the external portion is primed.  The manual states that the tank internals should not be primed.

Getting read for the first installment of Pro Seal

Rivets and misc. parts soaking in MEK.

This may seem like Pro Seal overkill, but in my mind too much is better than not enough.

Preparing the left and right tank skins for the bottom stiffeners.
Drain connector installed on the bottom left fuel tank.  This is where a drain valve will connect.

Tank stiffeners installed on the left wing.
Up until this point, I have progressed rather slowly with the tanks.  I suspect that my slow pace will continue until Section 16 is complete.  I plan to alternate between the left and right tanks instead of working through one before starting the other.