Wings: Rear spar. Attached.

The rear spars are on.  

My new longeron yoke was useful, but there were still some rivets it couldn't reach, so a few had to be banged out.

There are three rivets with minor smileys.  Not bad enough to warrant replacing.  Also, one rivet has a poor shop end since the bucking bar walked out to the edge.  I would love to replace it, but I'm sure I'd make it worse by elongating the hole since the factory head is nestled away between a flange and a web (I eventually replaced this).

Speaking of which, it's not easy to remove rivets whose factory head is on the flange of the rib since there's no good way to get a drill into that area.  How do I know?  Because I used a -6 length where I should have used a -8 on the doubler plate.  Trying to remove it was extremely difficult.  I used the die grinder to get in as close as I could and drilled a hole in the factory head.  Using a punch, I then tried to pry the head off only to "strip" the drilled hole leaving no point of leverage.  Then all I could do was try to remove the rivet from the shop end.  And when your rivet is already too short, there isn't much to work with on that side.  So in the end, I had to drill out the entire rivet, making the hole slightly bigger.  As a result, even the -8's shop end sits too low.  I would have needed a -9 so there was more shank to take up the additional volume introduced by the elongated hole.  So very little, if anything at all, was gained trying to replace that rivet.  Oh well.  What's done is done.

A similar issue occurred when riveting the torque tube support bracket to the right side rib:  Because on this rib I put the factory heads on the rib flange, I didn't rivet in the bracket until afterwards (to give space for the rivet gun).  This meant that I couldn't use the squeezer on one of the rivets because the flange bearing VA-146 was too high.  So using the offset rivet set, a major smiley was introduced into the rivet, enough to warrant replacement.  I should have used the 12" #40 drill bit to get to that rivet's factory head, but I didn't.  Long story short, I made a mess of the removal, making the hole very large and introducing many gouges into the body of the bracket, requiring lots of sanding.  You can see some of the mess in the image below on the right side.  I'll need to reprime that area before replacing the rivet.  I will use a -5 instead of a -4 rivet to make sure there is enough shank to fill up the extra volume of the elongated hole.

Building an airplane is a very humbling experience.  Many times one reflects on whether this was a good idea.  Time to push on.

Wings: Rear spar. Flap and aileron brackets riveted.

Following the priming of the rear spar components, previously, it was time to rivet together the aileron brackets.  Here they are, front and back.  The white/gray ones are due to there being two kinds of primer on them.  White:  EkoPoxy.  Gray:  Napa 7220.  On these brackets, I didn't like how the AN426AD4s were sitting in the countersinks.  They were just barely proud.  So I hit the holes again with the countersink bit to make sure the rivets would be perfectly flush, then spot primed the holes (hence the gray).  

 

One of the tasks required in assembling the aileron brackets is pressing in a bearing at the apex of the parts.  They suggest pressing the bearing in on a vise with a 7/16" and 9/16" socket on both sides.  It took some finesse, but I finally got the hang of it.  Of course, it just pushed out all the primer in the hole.  Here's a shot looking down on the vise with the sockets lined up on a bearing bracket spacer.  Slowly increasing the vise pressure pushes the bearing in.  Then, I double-checked to make sure the bearing wasn't seized due to warping.  When riveting the apex together, I applied clamping force with the vise to reduce any separation of the three bracket constituents.

Once the rear spars had all their doublers riveted in place, it was time to ream the critical hole.  That encompassed lining up the spar on the drill press and using the level to make sure everyone was orthogonal.  Here's a close-up following the reaming of the left rear spar.

And finally, here are the rear spars, ready to be riveted to the main spar via the ribs.  The yoke on the Main Squeeze couldn't quite reach in there without terrorizing the ribs.  Since I really don't want to bang these rivets with the gun, I'll pick up a longeron yoke to get the extra reach.  So, until I get that part, it's time to take a break from building and go play in the sky with a working airplane!

Wings: Rear spar. Priming rear spar.

4 hours of prep and priming and all parts for the rear spar are done, including some J-stiffener.

The night before, I was thinking that I should test the spray gun since I last primed the ribs.  I figured something might have gummed up in there despite my having fastidiously cleaned it out after using it the first time.  I didn't get around to doing that.  So after cleaning and etching all the parts, I fired up the gun with some water and all that came out was air.  1 hour later, following a near complete disassembly (and serious consideration of an emergency run to buy a new gun), I determined that the plunger which controls the valve opening/closing the fluid was stuck and wouldn't open.

  Next will be :

1. Riveting together the new right torque-tube bracket to fix my error from before.
2. Putting the inboard-most rib on the right spar.
3. Riveting that torque tube support bracket to that rib.
4. Riveting the aileron brackets together.
5. Riveting the various doublers to the spar.  
6. Ream out the "critical hole" in the forks and doublers.  No mistakes allowed here.
7. Rivet the rear spar assemblies to the ribs on the main spar.

Wings: Rear spar. Dimpled and doubler plates fabricated.

Been working on the rear spar.  As part of that, you're required to build the aileron hinge bracket assemblies.  These parts are not straight after having been manufactured, so into the vice they went, sandwiched between pieces of wood, and slowly worked as straight as can be.  The rear spar reinforcement fork and doubler plate are also hopelessly warped.  It takes a lot of time to straighten those out.

The WD-1007D-L/R Outboard Rear Spar Doubler Plates need to have a funny-shaped hole cut into them to fit the aileron pushrods.  A search of the 'net shows that these holes are problematic for many people in that their pushrods rub against these holes.  There's no way to test them until the ailerons are installed.  The plans provide templates to use to make the holes for both wings.  Turns out, they're not properly scaled on the paper, so I rescaled them and printed them out.  Even still, one of the rows of holes doesn't line up.  But all the others do and I checked it against the spar and the pushrod template is in the right place.

I use the center punch to start those holes with a #40 and worked my way up to a 3/8", then sanity took over and I used the unibit to enlarge the holes all the way as shown in the template.  The shaded areas need to be removed via some other means.  My Dremel didn't have any tip that would fit the bill, so I tried to drill a series of holes to file through.  This was after I wised up and used the rear spar itself to trace out the shape of the hole (the paper method was good for the center punch locations).

But there was still too much material.  Off to Home Depot I went to grab a nibbler.  They don't have them in the store.  Amazon Prime to the rescue with $3.99 overnight shipping for a nibbler.  This nifty tool made short work of the aluminum. I used this 1/8" aluminum oxide grinding stone on my Dremel to round it out.  It's basically a really bad cutting stone.  It melts the aluminum very slowly, making it easy work, except when you want to remove a lot of material.  Then you have to be mindful of the heat generated.  Next it was just smoothing all that down to look and feel pretty with sandpaper and the miraculous finishing sander.  Below is the right side.  The left side isn't as good.  The nibbler doesn't fit at the top coming from the unmarked side (due to the flange), so I clipped just a bit too much off on one bite using the nibbler from the other side.  Won't be a problem.

On the rear spar, at the aileron attach points, there are doubler plates.  Not sure why (perhaps due to material thickness?), but the top flange of the rear spar that corresponds to the length of the doubler plates gets countersunk rather than dimpled.  So, off I went to countersink on the left wing's doubler first, utterly terrified since screwing up this piece would be costly.  I set the microstop using a piece of scrap angle, then went to the rear spar.  The bit chattered in the hole and it got elongated.  I did it to the next two holes too, though not as bad (all other holes, around 30-some total, are fine since I slowed down the drill speed).  I'll either need to 1) enlarge these corresponding skin holes to a #30 and use the Rivet of Shame or "oops" rivet (NAS1097AD4, shank of a AD4 but head of an AD3) and furthermore, pre-compress the rivet to make sure it fills that weird hole reasonably, 2) just set it up for a AN426AD4 all the way through or 3) replace the part.  Oops indeed.

Every part in Section 15 needs to be deburred:  Holes and edges. Turns out my hand-held screwdriver is a major hand-saver for this.  And I managed to find a way to run the spars across the Scotch-Brite wheel.  Time saver!

Both flanges in the rear spars have to be dimpled, where they weren't countersunk.  I used the DRDT-2 on the bottom flange since that flange is orthogonal to the web.  But the top flange is acute to the web, so using the DRDT-2 would distort the flange.  Instead, I used the Main Squeeze for those, ensuring that I aligned it properly to the flange angle before each press.  A piece of electrical tape on the backside of the Main Squeeze prevented it from gauging the web.

I also went ahead and deburred and dimpled the top J-stiffener (it's the first thing prepped in Section 13 and is installed in 16) so I can prime it with these parts.  I thought it was a good idea since the wing skins will be big and awkward during their prep without the J-stiffener floating around in the way too.

Tomorrow is etching and priming.  Then everything gets attached.