Today was a repeat of yesterday’s session, except with the left flap. I did everything in the same order, with one tiny exception. I didn’t cleco the top skin on while riveting the rear spar to allow a little more maneuvering room as shown here.

It was brutally cold in Maryland today. Super high winds, and temperatures in the single digits. With the kerosene torpedo heater cranked full blast it was all it could do to get the temperatures in the hangar into the high 30’s. While much more comfortable than outside, it was not a fun work environment. My dog wrapped himself in his blanket and strategically positioned himself for maximum warmth. 

Time to finish up the flaps!  Here is the right flap clecoed and placed in the makeshift cradle I made yesterday 

The first step was to rivet the rear spar while I could still access it. I used my long thin tungsten bar as shown in this picture. While it was a bit of a pain in the ass, it didn’t take too long to finish it up. 

No real pictures of the next step… I riveted all the interior ribs. I then riveted the inner rib that will be closes to the fuselage and provide the connection point for flap controls. Use MK-319 BS blind rivets. I also opted to use the same type of blind rivet for the rivet immediately under the nutplate.

After I riveted all the ribs, it was time to set up the pneumatic squeezer for the outside rib and the spar. I made quick work of the rib. 

Then it was time to blind rivet the spar to the ribs. I double checked that everything was complete before closing up the flaps, as I would no longer be able to access the areas to fix mistakes.

The last two steps were to use the squeezer to rivet the lower spar edge and hinge, and then to buck the top skin and spar. My wife sent me a message as I was starting that it was snowing and I should leave the hangar soon since I was in her car… which is a bit squirrelly on the road. I looked outside… no snow. In the quick time that I finished the spar, we had close to 2 inches on the road! Time for some e-brake slides between the hangars on my way out!

Here is the final product! One flap done… one more to go. I should be done tomorrow!

After priming the flaps in my last shop session, it was time to start final assembly. First thing first, I went to borrow my buddy Mike’s heater. Its better than my propane setup. I’ve never seen it state “LO” as the temperature. I guess it doesn’t read below 30… it was 20 degrees F outside… and in the hangar!

Nothing warms my soul like a little beer!

The first thing I needed to do was to make a cradle for the flaps. Van’s instructions calls for it, and its a good idea, but you can probably get by without one. I used some spare board I had laying around. I screwed the two pieces together. I used an end rib to trace where to cut, and then cut with a circular saw. I used my belt sander to make sure the bottoms were absolutely identical so they would mount to the bench and maintain a true alignment. 

I attached the little brackets I made for the ailerons as feet and then clamped the feet to the workbench. 

The first step was to rivet the rear spar and ribs. I started with the right flap, which unlike the left, required shims. 

Both flaps with the rear spar riveted to the ribs. 

Next, it was time to install the nut plates for the flap attachment point. Don’t forget to do this before you close up the flaps!

The nut plate is a little odd, in that it has one rivet through the 706 and the other just through the rib. The directions call for the 706 to be countersunk for a 426 rivet, but there is no mention of the other rivet. The rib is too thin of a material to countersink, and dimpling would likely leave the nut plate slightly uneven. The course of action chosen by several builders is to use an Oops rivet, which needs significantly less countersink.

Here is my Oops rivet set from Avery. For this I used the NAS 1097 3-3.5. 

In this picture I have already countersunk the hole for the Oops rivet (shown on the right). I have placed the Oops rivet in the left un-countersunk hole to show how little it protrudes. 

This picture is a standard 426 rivet for comparison. 

Final products.