Left elevator tab bending, wing tank skin platenut drilling & deburring

I decided to tackle bending the tabs on the left elevator skin and trim tab. Rumor has it this is and the trim tab are the most common areas for mistakes on the empennage.

I stripped the vinyl from the tab area and marked a line perpendicular to the trim tab cutout. Then I fabricated some bending blocks at an 11 degree angle based on a survey of other builders' sites and a check with my protractor of the elevator finished angle.

The blocks were taped into place with double-sided tape. The pictures in the manual describe clamping it to the table, but they only show this for the trim tab, and I couldn't find an effective way to clamp the blocks while leaving myself enough room to work. Instead I clamped the elevator and the rear spar on both ends and hand-clamped the blocks while I worked first the bottom tab, then the top.

My lines must have been slightly too far inboard of the ideal, because I had to file the edge of the bottom tab to get it to clear the upper tab (in the photos, the bottom side is up).

Other than the filing, with some patience, a block of wood, and finishing the tab with the rivet gun & mushroom head set at 10 psi, the bottom tab moved into place.

 

The upper tab seemed to go smoothly as well until I hit it with the rivet gun. The block must have moved out of place, causing the radius of the bed to go from 1/8" (per spec) to about 1/64" (too small).

This could be a problem as radii less than 1/8" can lead to cracking at the bend.



I'll send the photo in to Vans and see if I need to remove the tab and fabricate a replacement, or if it's acceptable and just bears close inspection to ensure cracks don't form.



Aside from that minor setback, the tab bending was easier than I expected. I set the elevator aside and with help from Brian Judge pulled out the wing spars to mark orientation.

We noticed a spot near the etched serial numbers that looked like corrosion; it appears that the riveter may have skipped off the surface. I removed the corrosion with scotchbrite, and will clean & prime this later.

We drilled out the #40 holes for the tank skin platenuts, Brian deburred on the inside of the spars while I worked with the countersink on the outsides.

And then with the help of this lovely assistant we squeezed the first rivets on the wings!

Brian got to try his hand using the squeezer - his first rivets on the plane.

While I continued chewing aluminum with the countersink, Brian started edge-deburring the right rear spar.

We made great progress, and are officially started on the wings!! And almost exactly one year to the day that we started the empennage it's essentially finished - right on schedule. Not bad for a spring and summer where it felt like we were never home.

 

Thanks again to all the family & friends who've helped so far, and for those who haven't - you will.

 

Empennage: 2 hrs

 

Wings: 3 hrs