After researching this issue on vansairforce.net, I decided not to follow the plans again when it comes to the trim tab.  The trim tab and left elevator skins come with little ears that are supposed to be folded together to close in the end of the surfaces.  The problem is that many (most?) people end up not happy with these bends and either redo them (which would be expensive with the elevator skin) or live with it.  The consensus seems to be to just cut off the ears and fabricate little riblets to fit in there.  If you’re not happy with how these come out, you’re only wasting a few cents worth of scrap aluminum.

Here, I’ve cut off the ears on the trim tab and I’m ensuring that the cut line is perpendicular to the trailing edge.

I clecoed the top of the trim tab to the bottom of the elevator to mark where the cut line should be on the elevator skin.

Then moved 3/32″ away (the minimum gap between the trim tab and elevator), and marked the elevator skin.  You can see that I stuck a couple of extra rivets loosely in the holes for the trim spar to ensure these lines stayed perpendicular to it.

I took a little break from the trim tab to try my hand at some fiberglass work.  Here, I’ve fit the vertical stabilizer tip into place and drilled the holes to full size.  The tip was too long, so I had to cut off about 1/4″ (you can just see the blue line near the bottom edge) to line up with the vertical stabilizer joggle.

I also cut a piece of 1/4″ last-a-foam to fill the gap.  This stuff is really light, but it’s a bit brittle.  This piece snapped while I was trying to fill it.  It will epoxy back together though.

Here is the foam epoxied into place in the tip.  I left a slight reveal (less than 1/8″) to allow for some filler here since this area needs to be slightly concave to allow for the swing of the rudder.

The epoxy took too long to cure last night (even with the 205, fast hardener) to make any more progress, so I came out this morning to put the glass in place.  I used two pieces on each size of lightweight 1.45 oz cloth (the flexible stuff you see hanging off the sides).  I covered it all with peel ply (dacron) which is the stiffer looking cloth you see in the middle.

After work, I peeled off the peel-ply and trimmed the overhanging fiberglass.  Looks pretty good for a first effort.

I also mixed up some epoxy with some WS410 (microlight fairing filter) and filled the open end.  I’ll sand this back to prove a concave surface to allow the rudder to swing freely while still providing a tight joint.

I dimpled the left elevator skin in preparation for riveting.

I did a little more work on the trim tab tonight too.  It’s hard to see here because of all the clecos and cleco clamps, but the trim tab horns have been match drilled to the trim tab skin.

I attached the fairing last night with some pop rivets (sorry, no pictures), and put a layer of the 1.45oz/yd fabric over the joint.  This morning, I removed the peel-ply and did a little sanding.  The joint looks pretty smooth now, but with a little lightweight filler, this will be sweet!

I riveted the left elevator skin to the structure and bolted on the counterweight.

Here’s a shot of the complex intersections of the spar, counterweight rib, elevator skin and counterweight skin.  These rivets turned out even nicer than on the right elevator.

I did a little more prep on the trim tab as well.  Here are the holes in the trim tab spar, countersunk to accept the skin dimples.  These are countersunk because the trim tab hinge will mount flush to the underside of this flange.

I worked all day today, but managed to make a little bit of progress on the elevator trim tab.  I positioned and drilled the hinge to the trim tab.

I attached the trim tab servo to get it out of the way.

I prepped and primed the parts for the trim tab.  I can’t start riveting these tonight since the spar is back-riveted onto the skin and that will make too much noise.

I back-riveted the row of rivets attaching the trim tab spar to the bottom of the trim tab.  I also back riveted the trim tab horn on.  I left out the rivets along the edge on each end so that the rib I’ll be fabricating can rivet through that as well.

I used a long piece of aluminum angle to ensure the trailing edge of the trim tab aligns with the trailing edge of the elevator (and ensured the inboard edges are aligned).

I drilled the forward part of the hinge to the elevator.  The clearance between the elevator and trim tab (below my thumb) is intentionally too tight right now.  I’ll file this back to the recommended minimum clearance of 3/32″.

Since I’m deviating from the plans and cut off the ears on the elevator and trim tab that are normally folded over to close off the end, I started trying to fabricate the ribs that will be used instead.  Here’s the rib that will fit into the end of the elevator.

And here it is installed.  Luckily, the first one I made fit really well.  I tried making one for the end of the trim tab, but that will need to be remade.  Fortunately by doing it this way, if you screw up, you’re only wasting a few cents on aluminum instead of a large part that requires an order from Van’s to replace.

My buddy Andre stopped by tonight to help me roll the leading edges of the elevators.  They turned out better than the rudder, but this is still a pretty non-precision part of the construction.  My hands are killing me after this, so I’m done for the night.