Step 3.4, Rudder trailing edge

The first thing is this.  I now know with the advantage of hindsight, that the rudder trailing edge is a bitch.  Fortunately for you, gentle reader, you won't have to endure all of the gory details because I didn't take many pictures.  But suffice it to say that if someone had managed to capture my image during that time I wouldn't have been smiling.

It all started innocuously enough. The build manual goes into considerable detail for this step and  I should have been smart enough to see that as a warning.  Especially when many of the other instructions to this point have been flamboyantly lacking in same (level of detail).

To prepare for the joining of the left and right rudder skins along the trailing edge, I used a piece of steel angle to provide an absolutely straight edge along which I will cleco, clamp, or otherwise confine the rudder trailing edge prior to riveting.

I found that I needed to shim one end, but after polishing the surface the angle was as flat as my level was straight.  That is, I used a four foot level to check the flatness and no light could be seen between the two.  Everything was going great so far.

Polished and ready

As the next step, I used the AEX wedge, that will be riveted between the trailing edge skins, to match drill into the angle below, clecoing as I went.   Here is what the wedge piece looks like. Only a half inch wide, it  runs the length of the trailing edge.

AEX wedge during preassembly

Then the microstop counter sink cage comes out and the AEX wedge is counter sunk to accept the dimpled skins.

Iceberg dead ahead!  "Nonsense", I thought, and proceeded merrily along until I broke the tip off of my only #40 piloted countersink.  Crap.  It seems that the pilot tip got bound up with the steel angle below -- probably due to the hole not being drilled precisely to the same angle as the AEX wedge.  Now what? Go to the Internet, of course.

The new counter sink   vs.  One modified by an idiot

With the project on hold, I devise a new plan. A two part plan. The concept is deceptively simple, but whose execution requires the coordination of dozens of dedicated individuals, with precision timing, and tireless devotion to the plan's success.  FedEx handles the first part, while I alone, will be responsible for the second.  Which is waiting for the part to arrive.

36 hours later I was back in business.  I completed the countersinking over my carpet scrap instead of on the steel angle without incident.  The next step is to epoxy the AEX wedge in between the rudder skins.  And so this is where the perfectly straight angle piece comes into play.  I used my favorite epoxy, JB weld, although the build manual suggests a 30 minute epoxy.  I think one would be too rushed in 30 minutes to complete this process.

Butter up both sides of the wedge with epoxy and slip it between the skins.  Easy, squeezy!  Not so fast.  There's a little matter of epoxy squeezing out everywhere.  Ok, use a screw driver to scrape off the epoxy coming out of the trailing edge.  Now I start to worry about the clecos being permanently bonded to the rudder and steel angle.  So I take all of the clecos back out and clean them with acetone and the dimples as well.  This gives me a chance to take look under the skin for any seepage there.  Put all of the clecos back in.  Go have dinner, but worry about further seepage of the epoxy in to the dimples and around the clecos.  Go back out to the shop and remove the clecos once again, clean and replace.  Now I see how OCDs get started!

Rudder on edge is barely visible

trailing edge epoxied

The next day the trailing edge is bonded to the wedge and not the angle.  And all of the clecos come out without any difficulty. Yea!  I didn't suspect the the hard part was just beginning.  Double flush riveting the trailing edge.  Double flush means the shop head is pounded flat into dimple on the reverse side.  I start as the manual directs by preparing to back rivet the trailing edge.  The manufactured heads are taped in on one side and the rudder is flipped over.  The rudder edge is moved back a 1/4 inch such that the rivets will not be pounded against the holes drilled for the clecos.  Using the mushroom set on the rivet gun, the rivets are partially set normal to the rivet shank and then at an angle that matches the taper of the rudder as the rivets are nearly finished.

It sounds easy, but as soon as the riveting starts the rudder is moving all around.  I stop several times to clamp and re-clamp the restless rudder to no avail.  All of this movement causes the rivet set to migrate over into areas that I would just as soon not see it go.  Ultimately all of this wrestling leaves some minor dings along the edge that should have been avoided.

Here's the good one

Shop head side

Manufactured head side

Well, now that it is finished, I can confidently say that much of the trouble could have been avoided if I had drilled 5 or 6 new holes when the edge was moved back to clear the cleco line.  Just a few clecos in the new holes would have been sufficient to stabilize the rudder while riveting.  Lesson learned.  I am not only a genius at hindsight, I have also been recognized as a quarterback of the arm chair :)