After Tami and I got the leading edge riveted together, I decided that I would jump right into working on the fuel tank.  On the right wing, I started working on the landing light right after I riveted the leading edge together.  However, Tami and I are dreading the left (AND FINAL) fuel tank work.

Tank work tonight went really fast because I had already cut the inspection cover hole in the rib when I worked on the right fuel tank.  All I had to do is layout the reinforcement ring, clamp in place and drill for the nutplate holes.

#40 for the nutplate rivet holes
#19 for the nutplate screw hole.

As for orientation of the reinforcement ring, I decided to orient the ring exactly like I had for the right fuel tank.  As with the right fuel tank, my particular orientation places a nutplate in close proximity to the ribs aft tooling hole.  I had concluded on the right wing that the nutplate proximity to the tooling hole would not be a problem.

Here I have just completed drilling all of the nutplate holes in the rib and reinforcement ring.

One thing to note here that I did not discuss during the right wing was a minor "style point".  When I cut the hole in the rib for the inspection cover, I did not get it exactly matched with the diameter of the reinforcement ring.  IT WAS REALLY CLOSE, but not EXACT.  So I loaded up the die grinder with a rotary burr bit and "chased" the hole until I got the inspection cover hole on both the rib and reinforcement ring the exact diameter.  To polish the edge off, I switched the die grinder to a 1" unitized Scotchbrite wheel and put a nice finish on it.  I know....  you can't see it after the inspection cover is on, but I like to show some "craftsmanship" when things finally go together.

A picture below showing my progress so far tonight.  As with the right fuel tank, I have two 4D ELL's, one for the tank vent fitting, and the other for a fuel vapor return line (lower ELL fitting).  Last but not least, I cut the hole for the capacitance sender BNC fitting.

Since I didn't have to cut the fuel tank attach angle (that took almost 2 hrs to cut out during the right fuel tank), I could go right to drilling the attach angle to the rib and reinforcement plate.  The one thing I did on this fuel tank that I didn't do on the right fuel tank was to put the holes that run along the aft side of the angle farther away from the angle.  I am not installing a flop tube on this tank, so I don't have the added problem of needing to clear a 6D ELL fitting and nut.  This lets me put rivets wherever I want (more or less).

Just a picture of the reinforcement plate that will be riveted to the inside of the inboard rib.

I am almost ready to start sealing the inboard rib hardware in place.

Tomorrow, I should be able to fabricate all the outboard rib reinforcements and aft tooling hole cover plate.  My goal is to get the fuel tank ready to seal before we leave for Airventure next week.

After I fabricated my trap door for the 2nd inboard rib, I got some feedback from Bill in nearby Kansas City stating that I should close up the larger hole in the center of the rib.

Always asking twice and riveting once, I shot an e-mail off to Van's to double check the constructive feedback offered by Bill.  Here is that correspondence:

So after giving all this new information some time to sink in, I decided that I probably wouldn't be doing any "knife edge" flying, however, I am installing a flop tube to open up the plane to being able to utilize its aerobatic personality.  Therefore, I decided to install the plate to cover up the rib hole (since it would be difficult or impossible to do later).

I just fabricated a plate larger than the rib hole and countersunk it to accept AN426AD3-3.5 rivets.  This was kind of a problem in that I wanted to use AN470 rivets, but I didn't have any that were short enough.  I didn't think that it was really necessary to countersink and install flush rivets, but they were the shortest I had.  I did look at a rivet cutter, but couldn't justify the expense for just a couple of rivets.  Maybe I will buy at some later date...

The hole to the right is the capacitance sender mounting hole.  And YES, the spacer washers do clear the plate.  I had to check when typing this entry as the cover plate looks pretty close in the picture.  I hate it when I have those "ooohhh-crap" insights after the fact.

The rest of the night was spent roughing up the rib flanges and tank skin in preparation for riveting them in (finally).  No pictures...   Pretty boring stuff.  Tonight I realized that I have really under estimated all this miscellaneous tank work.  I had hoped to be done with the tank about 2 weeks ago.

Only specialized words can be used to describe construction progress on this Memorial Day Weekend.  Fargin-Nuget!!!!!  I didn't get diddly squat done on the plane this weekend.  Last week I was planning on having a "tank marathon" this weekend.  THAT DIDN'T HAPPEN!!!

Instead, I got caught up working on things around the house.  My "To-Do's" have been growing and I only got a couple of them done this weekend.  I could spend the rest of the summer on them and probably not get done.
This weekend's accomplishments included:

• Overhauling the gas grill.  Believe it or not, this took over 4 hours to clean and replace everything.  If you think tank sealant is messy....  It is nothing when compared to the muck I found in the grill that I haven't cleaned for probably 4 years.  YUK!!!!
• Mounted a wall mount for the TV.  Now I have room for my satellite receiver and a DVD player in the garage.  200 satellite channels and I still have a hard time finding something decent to watch.
• The BIG item for the weekend was wiring and mounting my new 24,000 BTU, ductless, split-type heat pump for the garage.  LINK TO:  Garage Heat Pump
• Minor work on the right wing tank.

Tami and I dimpled the tank skin.  The thing to be careful with here is not to dimple the fuel sampling rivet holes as the fuel sampling flange is countersunk by Van's.  The other holes you don't want to dimple on the skin is the rivet holes for that will attach the tank baffle.  The tank skin is to be countersunk  (have not done that yet).   After Tami and I got done with the skins, I dimpled the tank ribs.  Just another exercise in using the C-frame dimpler and the pneumatic squeezer.  Sorry, no pictures.

I am still fabricating components for this friggin' fuel tank.  I started working on the fuel trap door that blocks off a large hole in the same compartment as the flop tube.  The idea here is that the trap door flops down to block the hole and prevent a mass exodus of fuel adjacent to the flop tube during aerobatic maneuvers.  Okay, if you say so Vans.  I don't think that it would be a good idea to starve engine during aerobatic maneuvers.  The plane would only take you to the scene of the crash.  That could make for a really bad day.

I used some AN257-P3 piano hinge and cut it to 2.5" long.  It later gets cut to 1.75" so that you can bend up the tab to act as a stop.  I used some scrap 0.025" aluminum to fabricate the trap door.

Additionally, I cut a curved notch along the aft side of the trap door so that it did not block the notch in the lower portion of the rib.  Van's states that this notch in the rib is to allow water to migrate and pool at the bottom of the tank near the drain valve.  I wanted to make sure the trap door didn't hinder that water migration.

I riveted the trap door to the hinge with AN426AD3-3.5 rivets.  For the top side of the hinge to rib web, I used AN470AD4-4 rivets.  I didn't want to mess with countersinking the hinge, so I just used universal rivets.  Van's instructions on the print do not specify the rivets to use.  Those rivets ought to hold that friggin' trap door on....

Finally, I bent the hinge pin 90 degrees on the aft side of the trap door.  When the fuel tank is fully assembled, the tank baffle plate will be riveted to the aft rib flange and prevent the hinge pin from coming out.  If that hinge pin comes out, I am going to have serious other problems to deal with...

One long weekend, one piddly little trap door fabricated.  I gotta pick up the pace here.  Two other builders whose progress I follow regularly (David R. and Dave P.) smoked me this weekend on progress.  Good job guys.  I will get out of my slump soon.  I must have this subconscious phobia with working on the tank....

Today, the weather was absolutely beautiful.  The hot temps and high humidities we have had over the last week were gone.  This made a great day for working in the garage on the plane.

First thing I did today was figure out where I was going to place the rivet holes for the T-410 reinforcement plate ( T-405, tank attach angle).  Van's does not give you any real information on where to put these rivet holes.  They just say "fabricate it".  I just tried to come up with the same number of holes they show on the print.

The key here is that if you are installing a flop tube, placement of these rivet holes more restrictive as you have to drill a 9/16" hole to accommodate the flop tube AN fitting.

Here are the rivet locations match drilled to the attach angle.  Everything looks pretty good here, however, the three holes in a line by the angle are a little close to the bend.  If I put the factory heads on the reinforcement plate side (T-410), I will have plenty for the shop head on the T-405 attach angle.  The big question is:  Will I be able to orient those rivets that way when it comes time to shoot them?

The other thing worth mentioning here is that the T-405 attach angle does NOT go all the way up to the flange of the rib.  The reason being is that there are rivet holes along the T-405 that sits on the flange of the rib.  I left room for the shop heads of the tank skin-to-rib rivets.  Van's instructions do not make any mention of this and if you are not thinking ahead (my typical problem), you could be inventing new cuss words later on.  I guess they figure that if you are this far on the plane, you should just know those things.  Okay, but I am going to miss something sooner or later.

I decided that I would install a flop tube in the right wing.  Therefore, I needed to drill a 9/16" hole into the T-405 attach angle, the rib, and the T-410 reinforcement plate.  Don't ask me why I drilled the attach angle in this orientation...  Ooohh yea, I remember why....  The drill chuck was going to rub on the attach angle when I went to drill from the other side.  I just used a couple of quick clamps and C-clamps to hold the angle to some scrap wood.  Worked great. 

Just another close up picture of the measures I had to take in order to drill this hole.

Hey, what do you know...  The flop tube fits.  I looked at my rivet hole placement to make sure that the rivets would not interfere with the flop tube AN fittings.

I left my holes as close to the edges as I could and I probably do not have any more than 1/16" from any rivet to the nut that secures the flop tube AN fitting.  Builder beware...

Next, I moved on to drilling the reinforcement ring for the inspection cover.  Nothing really high tech here.  To figure out how / where I was going to orient the plate nut holes, I used the aft flange of the rib and measured to the edge of two screw holes and rotated the plate until two screw holes measured equally.  Now ask me if it matters....  I don't think so.....

I then proceeded on to dimple the plate nut RIVET HOLES in the rib and countersunk the plate nut rivet holes on the reinforcement ring.  Note the location of one of the aft plate nuts highlighted with the arrow.  It sets right next to the tooling hole in the rib.  You cannot see this when the reinforcement ring is placed on the rib.  I would consider re-orienting the plate nut locations to give me more distance between the plate nuts and the tooling hole.

I had bought these floating, sealed plate nuts a while back with intentions to use them for the inspection hole plate nuts.  The idea here is that the inspection plate screws are sealed off from the tank eliminating them as a source of leakage.  If you need to open your tank up, it is no big deal as you shouldn't have to take any extraordinary measures to seal it back up.

I got these from Wicks Aircraft Supply.  (Floating Plate Nuts:  NAS1473A08)

Okay, I got all the plate nuts installed and was admiring my work.  These look pretty good.

The one trick here is that the rivet holes are so close to the screw cavity, it was difficult to rivet these on.  I could barely get the squeezer square.

Then I realized I had somewhat of a problem.  I held the rib up to the light and I could see light between the rib and the reinforcement ring.  Okay, why did I spend money on the fancy plate nuts if I am not going to have a fuel tight seal between the rib and the reinforcement ring?  There are four major locations where a leak can occur in the inspection plate area:

1. Gasket between the rib and the cover plate
2. Plate nut rivets
3. Cover plate screws
4. Small tooling hole that sits under the reinforcement ring.  It would be covered by the cover's cork gasket, but not by much.

Considering my options here, I decided tooooo.....  drill out all of the plate nuts and prepare for my first session playing with tank sealant.  I decided that this would be a good practice session.  Since it is really not required to be sealed, I didn't have anything to lose if the tank sealant kicked my butt.  I got prepped up for the NEW experience I was about to under take. 

1. I soaked the rivets in MEK
2. Scrubbed all my parts down with a scotchbrite pad and Alumiprep. 
3. Wiped down all my parts with a clean rag and MEK (not required if you cleaned/etched with Alumiprep).
4. Measured out and mixed up a batch of tank sealant.  (10 to 1) ratio using a digital cooking scale I got from Wal-Mart (Worked GREAT).
5. Organized my tools and equipment so I wouldn't have to go searching for them with messy gloves.
6. Recruited Tami to help clean parts as I finished.

I didn't get a lot of pictures while doing this as Tami doesn't usually want to run the camera.  However, today she thought that was a better deal that using the little spatula's to spread sealant.

Here I am only a little over half way done installing the 12 plate nuts for inspection hole.  Dealing with tank sealant was definitely a new experience.  Once the sealant gets on your gloves, you stick to EVERYTHING.  I tried to pick up a rivet and 10 rivets would stick to my glove. 

I frosted up the mating surfaces of the rib and reinforcement ring, clecoed them together.  I then frosted the plate nut flanges then clecoed them to the reinforcement ring.  Last but not least, I put a little sealant in the dimples for the flush rivet factory heads.

With sealant all over (by this time), I had a hard time finding my rivet holes and the rivets I put in them.  As sticky and gooey as this stuff is, try and put your squeezer on it.  It was like trying to hold a GREASED PIG.  The squeezer dies slid all over the place.  I couldn't believe it !!!

In the picture below, you can sort of see how messy this was getting.  I had to wipe some of the sealant off the shop heads after setting them as I wanted to see if I got the rivet set properly.  I gave up trying to keep this looking neat until after I got done setting all of the plate nuts...

I had Tami cut my painters rags up into little "swatches".  As soon as you get sealant on the rags, it was just better to toss them.  When dirty, they just smear sealant around.  A lot of trash for such a small sealant effort.

Here is what the inspection hole looked like after I got everything frosted up and cleaned all the excess sealant off.  Can you figure out what I forgot in the picture below?

Yep, you guessed it...  I need to install an anti-hang up bracket over the inspection hole since I am using a flop tube in this tank.  I will wait until the sealant sets, otherwise I would never get all the aluminum shavings out of that new sealant.  I couldn't even imagine....

If all goes well here, I have eliminated 3 of the 4 leakage paths I discussed above.  All I have to worry about is the large hole.  Van's has you seal the cover plate with a cork gasket.  I know some builders who use tank sealant to seal the cover plate and throw the cork gasket away.  I am not sure what I will be doing yet.

Today, I started trying to remember where I left off during my last real building session.   I decided to start drilling the fuel drain flange (VA-112).  I lined the center hole up with the pre-punched hole in the skin and oriented the pre-countersunk rivet holes so that they lined up forward to aft.
Once I had my alignment close, I used a quick clamp to hold it in position.

This is a staged photo, but to ensure that I was lined up forward and aft, I measured from the center of the most forward (and most aft) rivet hole to the edge of the skin.  I had to rotated the drain flange slightly so that the two measurements were equal.  Theoretically, my holes should line up forward to aft now.

I drilled the first hole and stuck a cleco in it.  After each hole, I stuck a cleo in it....  Duh....  When I was done, it looked great. 

Okay, here is the first screw-up I FOUND today.  On my 5/10/04 and 5/11/04 log entries I detailed how I fabricated the tank attach angle and how I cut the inspection hole into the R-703 tank rib.  Okay, here is the screw-up part.  When I THOUGHT I was working on the right wing inboard rib....  I had actually cut the inspection hole on the outboard rib.  Dag-BERNIT!!!!  Okay, it is not a big deal yet.  I can just exchange the inboard rib on the left wing, put it on the right outboard wing rib location.  Take the rib I previously cut the inspection hole for and fabricated the attach angle and use it on the left wing.  Then it is just intuitively obvious to the most casual observer all I have to do is correctly cutout the inboard rib on the right wing and fabricate the attach angle for the right wing...  Did I lose anybody???

The bad part of this whole deal is I thought I was going to move forward today and right out of the gate this morning I have to back track on the attach angle and rib.  I guess I am moving forward, as I won't have to do this again when I work on the left wing...

Again, it took me about 2 hours to cut the attach angle as that is some HEAVY angle stock...  I had aluminum chips flying everywhere by the time I was done.

I am pretty happy with both attach angles.  They turned out really good.  Lots of filing, fitting, filing some more AND fitting AGAIN... 

Some of the tools I was using and aluminum shavings I generated by the pound....

The last thing I decided to do today was to fabricate T-714 clip which is riveted to the fuel filler flange and is used to support the fuel tank vent line.  I just used some scrap aluminum I had from the emp trim kit.  Van's doesn't offer any dimensions other than make it out of .025" aluminum and a 1/2" wide.  Okee-Dokee, done.

Decided to call it an early night to watch a movie with Tami.  Chick flick ya know:  Something's Gotta Give.

Well, I have been procrastinating the fuel tank construction long enough.  For the most part, I have my landing light installed.  I have a few things that I need to do yet, but am waiting on parts.

I started building the tank by fabricating the tank attach angle (T-405).  The tank attach angle is fabricated from blank stock (AA6-187 x 2 x 2 1/2 x 12).  This is some heavy duty angle (as I found out trying to shape it).

For my first cut, I used the band saw.  Normally the band saw cuts through aluminum like a knife through warm butter, but not on this angle stock.  I had to exert some effort to feed this angle through.

Once I got it to the rough shape, I proceeded to the bench grinder and the scothbrite wheels.  It didn't take me to long to realize that using the scotchbrite wheels to take the angle to final dimensions was going to take me all night.  Sooo, I broke out the rotary burr bits.  Those worked a lot better than the scotchbrite wheels, but even as aggressive as those bits are, it took some time to shape the attach angle.

Also with all the shaping activities, I took my time to prevent excessive heating of the aluminum.  The rotary burr bits were able to remove more material and the angle did not heat up like it does on the scotchbrite wheels.  However, I was picking aluminum chips out of my hair and clothes the rest of the night.

After putzing with this for little over an hour, I was getting fairly close to having it shaped to the front of the rib.  At this point, I would take a little off with the scotchbrite wheel, fit it to the rib and see where I was hitting.  I repeated this cycle until I had the fit you see below.

Looks pretty good to me.

I am usually amazed at the thought Van's has put into some of their parts.  Below, you can see the T-410 reinforcement plate and the T-407 stiffener ring.  Taking all this apart, I felt like a kid building models again.  Twist the parts out, snip the tabs, and debur.  Discard the filler pieces.

Here you can see the T-410 reinforcement plate on the back side of the inboard rib.

Short night.  I am researching information on a air conditioner / heat pump for the garage.  It has already been in the 90's with suffocating humidity.  It makes for an uncomfortable building experience.  The air conditioner / heat pump is a lot of money and I would rather put that $$$ into the plane, but I am sure when it is 100 degree's outside, it would make building tolerable.  We'll see...