This log entry is just a cumulation of several shorter tank sessions.  I spent two separate nights sealing the inboard and outboard tank ribs and reinforcement plates.  Pretty straight forward, just really messy....

I ended up using the fuel pick-up tube that I fabricated a week ago or so.  It was long enough to clear the nutplates on the reinforcement ring.  It is not perfectly centered between the nutplate and stiffener.  What I was really demanding here is that the nothing touched and chaffed.  I tried twice to get a more centered fuel pick-up, but I wasn't any closer than this pick-up.  We are talking 1/16" difference here.  Precision tube bending....

Anyway, after I screwed on the inspection plate, I torqued the 6N fuel pick-up nut to 100 in-ibs.

I also torqued the vent line 4N fitting to 60 in-ibs. 

Notice that there are two wires on the inboard capacitive plate.  One connection goes to the outboard capacitive plate and the other connection goes to the BNC connector on the inboard tank rib.

Tank sealant for the inboard capacitive plate.

I applied sealant to the electrical hardware before I mounted the capacitive plate to the tank rib.  Made it a little easier to goop the tank sealant on and clean it up.

I fully encapsulated the outboard capacitive plate electrical hardware.

To attach the inspection plate, I used the cork gasket and "buttered" it with EZ-Turn lubricant and then placed it between the rib and the inspection plate.  I then attached the inspection plate with some 8-32 x 5/8" stainless steel socket head capscrews.  I wasn't able to torque them with a torque wrench, but I tried to tighten each screw equally by feel.

To finish off the fuel seal of the inspection plate, I topped the whole thing off with some tank sealant around the screws and the inspection plate.  Since I used EZ-Turn on the gasket, I removed all excessive lubricant as I doubt if the tank sealant would stick to it...   This is what I did with the right tank and I didn't have any sealing issues.

The only thing I have left on this tank is to get 1/2" of polypropylene tubing to insulate one of the capacitive plate mounting screws (long story), mount-solder-seal the BNC connector.  Then it is sealing the rear baffle plate and pressure testing.  Woo Hoo....

Tonight I was going to fly to the local EAA Chapter 80 meeting in Omaha, but I got a wild hair to knock out another session with tank sealant.  Since when is sealing fuel tanks more fun that going flying and talking about airplanes????  I must be breathing to many MEK vapors.

Now that I have my fuel pick-up fitting and anti-rotation bracket mounted to the inspection cover, I installed my newly fabricated fuel pick-up tube.  It fit better than Van's original pick-up tube, BUT....  I still am not super happy with the clearance between the tubing and the nutplate.  They don't touch each other, but that can't be more than the thickness of a couple of sheets of paper between the two.

I think that I am going to fabricate yet another fuel pick-up tube.  As you can see there is plenty of clearance between the stiffener and the tubing, but I had to work hard to see that the tubing and the nutplate don't touch.

Otherwise, I am really happy with how the fuel pick-up sits in the fuel tank.

The fuel pick-up sits nicely along the end rib and clear of the tank drain.  I guess this is a good example of why it is a good idea to sump your tank before flight.  If there is any water in the tank, the fuel pick-up sits very near what would be the lowest point in the tank when on the ground.

Anyway, I had enough tubing to attempt two new fuel pick-up fabrications.  I had one absolutely perfect so that the fuel pick-up was nearly centered in the clearance between the fuel tank stiffener and the pesky nutplate.  However, YOU MUST REMEMBER that when working with tubing, you must put the AN sleeve on AFTER you make the bend in this tube and BEFORE you flare the end.  I made that same mistake X2!!!!!!! Dam-it....  It only cost me about 2 foot of tubing (a whole $1.38), but it was the last 3/8" tubing I had.  Okay, time to surf Wicks Aircraft Supply.

Okay, now that my fuel pick-up is not a done deal yet, I decided to move onto prepping and sealing the fuel tank filler flange and vent tubing clip.  I had everything ready on the fuel filler flange, so all I had to do before sealing was to finish fabricating the vent line clip.

I made this clip a fair amount shorter (less than 3/4", but noticeably shorter than the right tank).

When I clecoed the vent clip to the filler flange, I looked down the tank and it lined up almost perfectly with the tooling hole for the vent line.  In the background, you can see my vent and fuel return fittings on the inboard rib.

Where the vent clip butted up against the neck of the fuel filler flange, I radiused it slightly.  My thought here was to allow it to "hug" the neck of the filler flange which would keep it from twisting.  The vent clip is only held by one rivet and it doesn't take to much effort to twist it.  It is kind of a mute point after you put the vent line through it.  It becomes pretty immobilized after that.

Pretty happy how this is looking so far.  Alright, where's the tank sealant?

Let the sealing fun begin....  I am rather generous when I put on tank sealant.  I have seen builders who have really small fillets and sealant lines that look like a work of art (which is very difficult if you have ever worked with this messy, sticky stuff).  Then they go to leak test their tanks and sure enough, they leak.  My approach has been to fully encapsulate rivet heads and flanges.  What I work hard to stay away from is to have "stringy" messes all over the inside of the fuel tank.  Those little chunks of sealant that can become dislodged and make their way to the fuel pick-up.

I got the fuel filler neck riveted and sealed.  Then I spent about as much time again cleaning the area so I had none of those small, stingy, blobs of sealant I was talking about.

Nothing is fun about riveting this flange in.  Van's calls out AN426AD3-4 rivets for this fuel flange (when you are using the kits standard, non-locking flange).  The problem is that I upgraded my fuel cap to the locking style which has a different flange.  It is thicker on the sides and thinner on the forward and aft sides of the flange.  I reviewed my log entries for the right fuel tank and I didn't make any mention of trouble with rivet length.  It was clear that the rivets Van's called out were going to be to short in some of the areas around the flange (see my rivet call out below).

I saved the forward rivet that holds the vent clip until last.  This rivet gave me a hard time on the last tank and on this tank, I didn't have any problems.  As I detail in my right tank, the best solution I could come up with for riveting the forward rivet that holds the vent clip was to use the rivet hammer with the back rivet attachment on the shop head side of the rivet.  I used the bucking bar on the skin side of the rivet.  The reason I saved this rivet until last, was that in order to get the rivet hammer on the inside of the tank, you have remove the fuel tank from the cradle and set the skins on the table.  The tank skins open up enough to get the rivet hammer on the inside.

Here is my unofficial rivet call out I used for my fuel filler flange.  The 3-5 rivets were a little long, but the 3-4.5 rivets were a little short.  Why does it have to be so complicated?  I ended up bending over one of the 3-5 rivets, so I did have to drill one rivet out.  That was better than last time, when I drilled the same rivet out 3 or so times.

I should have went up to the EAA meeting.....  I feel pretty good about having the fuel filler flange riveted and sealed.  One more tank sealant session behind me...  WooHoo...

Tami is in Minnesota again as her mom is back in the hospital.  She had promised me to spend all day working on sealing the left fuel tank.  Family takes priority, so I just worked on tank things that I can work on without her help.

In the right fuel tank, I put in a flop tube.  in the left fuel tank, I decided to stay with the conventional fuel pick-up called out by Vans.  I am also using capacitance fuel senders which means I will be using the "blank" inspection cover.  Therefore, the first thing I needed to do if figure out where to drill the hole for the fuel pick-up AN ELL fitting.  I had also purchased the pre-fabricated fuel pick-up from Van's (see second picture below).  To see where I stood on fuel pick-up location, I used the standard inspection cover that you would use if you were installing float sensors.
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I then installed the pre-fabricated fuel pick-up and immediately noticed a slight problem with routing of the pick-up.

I modified my nutplates from the standard kit in that I ordered sealed nutplates to eliminate all these screws as a possible leakage path from the tank.  However, the pate nuts interfered with the location of the fuel pick-up line.  The tubing was just to short to go between the skin, stiffener, and nutplate.

This obviously is not going to work with the ELL fitting in the same location as on the standard inspection cover plate.  I figured that I had to come down about an 1/8" to route the tubing under the nutplate.  So I tried to drill out the ELL fitting hole lower, however, when I test fit the ELL and the pickup tube, I didn't move the hole down far enough and I still had an interference problem with the pick-up tube and the nutplate.  Therefore, I am going to have to fabricate a new pick-up tube.

Well, now that I was committed to the hole in the inspection plate, I began to fabricate the anti-rotation bracket.  I actually cut the angle at 1 1/4" instead of the 1" called out by the plans.  Van's only gives you 2" of this angle to make two anti-rotation brackets.  Since I didn't need this on my right tank, I had some extra angle to work with so I just made the bracket a little wider than called for.

In order to properly place the anti-rotation bracket, I drilled the 9/16" hole for the ELL per Van's dimensions and then did the following to ensure correct placement and orientation since the ELL will not be able to rotate once the bracket is drilled and riveted to the inspection plate. 

• I put the ELL back into the original inspection plate (for float senders) as it has the two holes pre-punched where you would rivet the anti-rotation bracket to the inspection plate. 
• Centered the ELL fitting between the two #40 holes for the rivets to secure the anti-rotation bracket.
• Drilled #40 holes in the anti-rotation bracket.
• Removed all the hardware from the original inspection plate and installed it on the blank inspection cover plate.
• Installed the inspection plate back on the fuel tank and inboard rib.
• Installed the fuel pick-up line and oriented the fuel pick-up so that it wouldn't chafe on the nutplate or the tank stiffener.
• Tightened the ELL fitting so that it would not rotate if I bumped it and verified alignment of the fuel pick-up.
• Removed the inspection plate from the tank and put in the vise.
• Installed and clamped the anti-rotation bracket to the inspection plate and drilled out the holes between the Inspection plate and anti-rotation bracket to #40.  Replace my clamps with clecoes.
• Once I checked it over and was happy with alignment, I drilled out the holes to their final size of #30 since Van's calls out using a AN470AD4-6 rivets to secure the anti-rotation bracket to the inspection plate.

Ooh NO!!!!  Getting ready to deal with nasty tank sealant again.  I will be glad when my tanks are DONE!!!

I planned on doing a lot of little tank sealing activities.  I.e.: tank drain, end rib hole plate, inspection plate fuel pick-up hardware and sealing the new fuel pick-up tube screen.

I started on the tank drain fitting.  Hopefully, I remember how to do all this.  I took a scotchbrite pad and MEK and cleaned / roughed up both surfaces to be sealed.

Ditto for the inside of the skin.  When sealing here, I made sure that each rivet was fully encapsulated and that there was space between each "blob" of sealant so any moisture would be sure to find its way to the tank drain.

I dipped each rivet in sealant and made sure that when I clecoed the tank drain flange to the skin, that I had sealant ooze out all the way around.  My theory was to make sure that I had enough sealant between the flange and skin so as to not have any leakage paths.  I had really good luck by having no leaks on the right tank.  I hope I can repeat that on the left tank.

This is a hole that has to be covered and sealed on the outer most rib on the fuel tank.  I fabricated a small plate, riveted it with two rivets and placed a big glob of tank sealant over the cover plate.

I also place sealant on the factory head side of the rib.

The fuel pick-up ELL and anti-rotation bracket.  Just make sure that you DON't rivet the anti-rotation bracket in place before you install the ELL.  It's a "cart and the horse" kind of thing. 

I placed spacer washer is on the OUTSIDE of the inspection plate.  I placed tank sealant between all the surfaces, torqued the ELL fitting and nut to 130 in-Ibs and then covered the whole assembly in tank sealant.  As with all my tank rivets, I fully encapsulated the factory head for the anti-rotation bracket (which is on the outside of the inspection plate).

This is my new fabricated fuel pick-up.  The tubing on the one Van's sent me was to short to make it around the inspection nutplates.  So I saved the AN fitting and the screen and fabricated a new length of tubing.

Underneath the tank sealant for the screen, I safety wired (.032" safety wire) the screen onto the end of the fuel pick-up tubing.  There is a #40 hole through the end of the tubing that the safety wire is run through and then twisted.  I "packed" tank sealant around the end to help secure the screen.  Looks just like the one Van's had originally sent me.

Arrrggg, this is only the beginning of sealing this tank.  Everything I touched for the next hour had sealant on it.  Hands, TV, tools, etc.  This is some messy stuff.

After I got done cleaning up my mess, I decided to get the Cherokee out and fly up to Plattsmouth (KPMV) to see how Kevin Faris is coming along on his RV-7.  He is a lot closer to being ready to fly than I am.  I am really envious of his current status.  I will get there someday.  Sorry, no pictures.