Today, I set out to get more tank sealing done so that I could knock out sealing tank ribs next week.  I didn't think today's sealing efforts would take but a couple of hours and then I could get some work around the house done.  WRONG!!!  Tami and I riveted the leading edge together in about 2 hours.  Tank sealing is turning out to take me a WHOLE LOT of time.  Over 20 hrs of riveting and sealing and I haven't started on the ribs yet.

Below, I riveted in the anti-hangup bracket for the root rib inspection hole.  I fully encapulated the bracket and rivets.  Most builders do not do any sealing on this inspection hole as it is sealed by either the inspection cover gasket (if you use it) or the inspection cover plate is sealed with tank sealant to the outside of the root rib.  I have opted to use some after market sealed (floating) plate nuts.  I am hoping that sealing this reinforcement ring and other hardware, that I am able to use the gasket that is supplied with the kit.  If I need access to the tank or the gasket ever needs changing, no problem as my leakage paths here at the root rib are only through the "Big Hole" and not around every plate nut rivet and plate nut screw....

The next component sealed was the drain flange.  The drain flange was machine countersunk at the factory and the factory rivet heads are almost perfectly flush.  I frosted up the back side of the drain flange and slapped it on the skin and threw a couple of cleco's to hold it in place.  I was able to squeeze all of these rivets with the pneumatic squeezer.

Just another angle of the drain flange.

This is the back side of the drain flange.  As with all of my sealing to date, I fully encapsulate my rivet shop heads.  I tried to keep the skin between the rivets clear of tank sealant.  I didn't want any condensation in the tank from being impeded in its flow torward this drain flange.

This is a picture of my outboard rib tooling hole.  I cut a triangular shaped piece of aluminum and riveted it over the tooling hole.  The only trouble with this I had is that I didn't have any solid rivets short enough.  I did have some CherryMax universal blind rivets that were short enough.  The CherryMax universal rivet had a larger shop end.  The CherryMax rivet is really a pretty sophisticated rivet when you read through Textron's technical bulletin.  Link To:  CherryMax Rivets Info

I just placed copius amounts of tank sealant over everything.  This sucka is not going to leak.

This is the outboard side of the rib.  Again, plenty of tank sealant over the hole and the factory heads of the CherryMax universal rivet.

The last three sealing operations were not to bad.  Okay, now it is on to the problem child of today's efforts.  The fuel filler flange....  What a pain in the arse.  I started by clecoing the ribs in on both sides of the filler flange to hole the tank skin in its basic arc.  Then with all tank sealing efforts, I frosted up the filler flange to skin surface and cleco'd in place.  I got Tami to help me with this as I was not going to be able to reach every rivet with the pneumatic squeezer so I decided to buck these rivets.  They were all fairly straight forward with the exception of one rivet (read on).

After Tami and I got about 3/4 of the rivets set, we removed the ribs to gain acess to the remaining rivets, including the difficult one...

Okay, can you guess which rivet on the filler flange is the problem child???  Hint:  It holds the vent line clip (T-714).  How am I going to set that rivet?

• Grind down end of bucking bar to get in between the filler flange and the clip.  NOPE>>>  Didn't work.  The end of the bucking bar that was flattened with the grinder does not allow enough surface area to properly form the shop head.  DRILL OUT RIVET start over.

• Use pneumatic squeezer.  NOPE>>>  Yokes are not long enough.
• Back rivet against bench back rivet plate.  NOPE>>>  Didn't work.  Factory rivet head set high, couldn't get skin to set up against back rivet plate.  DRILL OUT RIVET start over.
• Hold bucking bar on factory head and form shop head with rivet hammer and back rivet attachment.  YEP, GETTING CLOSE.  However, flattened out rivet shop head.  *&$%*%*$#@!*.   DRILL OUT RIVET AGAIN, Inspect T-714 clip find out clip mounting point is distorted....  Fabricate new vent line clip and start over.

On the 4th try, I did get a properly set rivet.  However, I will do this rivet slightly different on the next tank.

As you can sort of see in the picture, the factory head is not completely flush on all sides.  This is in part due to the fact that this is where the skin has the most curvature.

One the next tank here is what I am going to do for this troublesome rivet:

• Use the bucking bar on the factory head side.
• Use the rivet hammer back rivet attachment to get in between the filler flange and the vent line clip.
• Use a short burst (2-3 hammers at a lower pressure (approx 35 psi with my Sioux 2x rivet hammer).
• Rotate (rock) the bucking bar a couple of degrees forward to attempt to keep the factory head flush with the curvature of the skin.
• Use a short burst (2-3 more hammers).
• Check shop head for proper dimensions.

After all of this, I was sticking to everything.  I spent the rest of the night cleaning up.  WooHoo....  Am I done with this tank yet?