First on today’s agenda was to do a little practice for the double flush rivets I would need to set for the forward fuse skin to F-821afb. I did this by drilling and dimpling a few holes in some scrap aluminum that had a similar thickness to the parts in question. Then I used a few different countersink depths and different rivet lengths in order to get an idea of exactly what I was looking for. My basic research online indicated that the best method is to make the countersink slightly less than that required for the machine head, as the shop head will not fill that size countersink fully. Using the rivet gauge, I found that because of the countersink, you’d want a half size to a full size shorter rivet than would be required without the countersink. This makes sense considering the gauge measures from the top of the countersink and as a result there is more area for the shop head to compress into. A couple practice squeezes later, and I had the results I was looking for.
The final step was to use a scotchbrite wheel to make the surface perfectly even. It would probably be best to use a rivet shaver first and then clean the area with the scotchbrite. Regardless, I’m confident that this rivet technique is a non-issue and I’m ready to tackle the real thing. 

I also disassembled the forward fuselage, in order to begin the process of deburring and dimpling the associated parts. Before I could begin this though I needed to take off a little more area near where the forward skin meets the upper longerons to have a perfectly even and continuous fit.   
You can see the area that needs to be removed marked in black. The dremel and the scotchbrite wheels made fairly quick work of this.
  
Next I turned my attention back to a few remaining tasks on the cockpit rails. In the Van’s diagrams there are two rivet holes that are marked to not be countersunk, nor riveted. No such annotation exists on the Show Planes instructions and I couldn’t seem to find what exactly the purpose was in the diagrams. (I’m pretty sure I’m missing a set of diagrams, which is normal for the big drawings, but not for the preview plans.) After taking a quick look at Jack Savage’s RV-8, it was apparent that these two rivet locations will become nut plates to attach the sliding canopy rails. Since these will not be needed in my kit, I drilled, deburred and dimpled these remaining holes. 

When assembling the aft fuselage, I had overlooked two parts. These are supports to the forward most upper bulkhead and provide a location for securing baggage in the rear compartment.   The fit was a little off, so I focused primarily on edge distance for the longeron as that is the most structurally important part in this equation.
When I drilled the rear passenger shoulder harness attach points, I had not notched the parts for overlapping the bulkhead flange. This would have resulted in a skin distortion when the part was riveted in place, so I took care of this today. I began the process of removing the blue plastic, deburring and dimpling skins. I no longer mess with removing portions of the blue plastic in portions. Just take it all off. The skin will need plenty of prep prior to priming and painting anyways, plus these skins will have very little opportunity for scratches.
  

When I attached the forward skin yesterday there were a few items I ignored in favor of focusing on the skin modifications. First among these were the baggage door support strips, that I had not included. I reattached the skin with these in place so they could be match drilled. 

Next I included the baggage door support rib and spacer. These require a dimple to the firewall.
  

The next bit is a little bit tricky. You need to clamp the F-821afb in place even with the new cut in the forward fuselage skin. Getting this perfectly even and centered can be done through multiple trial and error, as you can’t be assured that its even until you have a lot of clamps on place. The trick I used was to get it as reasonably close as my eyeball could get it. Then I marked the center of both parts (shown in red ink.) Next I measured the amount of offset, which was approximately 1/32 of an inch. I unclamped the part, adjusted the red marks 1/32″ and reclaimed. Easy day!
  After it was clamped in place, I began drilling and clecoing from the center out.

I’ve cleaned up the remaining work on the rail installation. Everything is deburred, and ready for the final installation of the new rails, save the nut plates between the F-804c bulkheads. Show Planes states that this should be a single leg nut plate that uses the existing rivet hole as the center hole and that the #6 screw hole should be approximately 1/4 inches from the longeron edge. The result would look something like the picture below (with the nut plate on the other side). However, this looks rather different from the picture, which is hard to make out. I plan to email Show Planes to make sure.  

I might be jumping ahead in the build a little bit, but I’m trying to get as many structural parts complete and ready for priming as I can for maximum efficiency. With that in mind I tackled the forward skin yesterday. This is a nerve racking cut, and it took me awhile of playing before I was happy with my lines. Here is the skin installed. You can see I’ve already made the cutout for the baggage compartment. You can see where the normal cutout for the stock kit would be made.

The lower cut is made parallel to the longeron. The longeron slopes down at this point, so you can make the cut with the skin still installed. Be vary careful at the beginning where the line is closest to the longeron. You do not want to cut that! The rest of the measurements are for the positioning of the 3/4″ radius at the corner. 25 3/4″ from the front, 1.5″ from the side, and 3/4″ from the nearest rivet.   

Here are my resulting lines.

At the top center, you’re looking for 4 inches from the bulkhead. You use the 821afb reinforcement to draw the line. This is the very tricky part. First I began by hand bending the reinforcement to match the skin as closely as possible. Then I used duct tape, and my measurements to correctly align everything. This took several iterations and a fair amount of tinkering until I was happy. Then I traced the line and removed everything for a final set of measurements. Then it was time for the radius.

I cheated just slightly on the 3/4″ radius. I used a 1 3/8″ unibit which is slightly smaller than required. I’ll clean up the remainder with a file and scotch brite wheel.   

Using a pneumatic cutting disc, I slowly made the cut. The rotating fuselage stand was invaluable during this entire process. Here are a few pictures of the result.
  

I used scotchbrite and a file to get everything cleaned up. There is still a little more cleanup to do. Particularly on the sides near the longerons which will need to be cleaned up after the removal of the skin. Finally, I added the 821abf reinforcement and clamped it in place. This will be double-flush riveted, which is something I’ve never done before, so more to follow on that.
  

My neighbor across the hangar keeps inadvertently leaving her tools in my hangar, so I made her a little box so she knows where everything is. She tends to whine a lot.