Time: 7 Hours
Today I got to have my weekly breakfast with some fellow builder which included a lot of hangar talk. That always fuels my passion to build making my dream of flying an RV-8 coming true that much sooner. When I got home I started the next step of this service bulletin which was to begin riveting all the parts together. To start I decided to hit the tough rivets first. These would be the ones on the fingers of the new doubler. They are tough because you have to rivet inside of the wing skin where there isn’t much room and you have to use a double offset rivet set. This set makes a “z” shape sort of allowing it to get close to the skin and have the gun perpendicular to the work. With a straight set your gun would be at an angle since the gun is thick. I fabricated a shim of sorts out of 1/4″ flat stock and gorilla tape. This allowed the rivet set to rest on it and be at the right height for the rivet.
On the other side I used my small bucking bar with a piece of scrape hinge to elevate it just enough to clear the bend of the spar.
I also taped the rivet gun around the rivet set as these tend to rotate as you use them and this will help keep it into the correct position.
These , although difficult, went pretty fast. Unfortunately I had to do one side then set everything up for the opposite side. I then flipped the HS over and repeated the process. Here are the first 5 which all turned out perfect.
I used the pneumatic squeezer to get as many of the interior rivets I could and the gun for everything else.
I realized on the first 2 rivets I set once I flipped the HS over that the 1/4″ flat stock was a little too thick by about a 1/16″ which held the rivet set up a little too high causing a smiley face on the rivet head. Not a big deal and certainly not worth drilling out. I created a new shim out several thinner pieces of aluminum taped together and the rest turned out perfect. Now I turned my attention to the main ribs I removed earlier. If you remember I cut off the forward flange if those ribs. That is due to now the spar area where those flanges sat is now thicker with the new doubler. This means that these would fit as they should. Van’s had a cure which is to take some thin angle stock and make a floating rib flange. Then you could get the fit just right and rivet that new flange in place making a perfect fit. I cut the stock and cleaned up all the edges. I then bent the stock to the 86.4° that is required for it to sit flush on the spar. I then grabbed some of my spring clamps and placed it into position on the rib.
Once you have that in place you can return the rib to its spot inside the skin. Once in position you release the clamps slightly and slide the angle up flush with the spar. Once there you can use some C clamps and tighten it down so that you can match drill the 4 holes in the spar and the 4 in the rib.
After all those holes were drilled in both ribs I cleaned up and deburred everything. A little scuffing and cleaner and they were ready for primer. I also cleaned up the forward spar areas where I nicked the primer and touched them up as well.
After letting the primer dry I riveted the angles to their respective ribs with the squeezer.
All that remained was to rivet the forward rib/spar/main rib holes, the main rib to rear spar holes and all the skin/rib holes. I used the double offset again for the rib/spar/rib rivets and the squeezer for the rest. Some may notice that I riveted every hole on the upper skin along the two ribs and spar. Normally you leave several holes open for future platenuts that will hold a fairing that ties the vertical stab and the horizontal stab together giving a clean look. I’m going to do the same but a much cleaned look with only 2 screws on top and 2 on bottom like my friend Glen did on his first RV-8. Since I’m not sure exactly where I will place those screws I filled in all the rivet holes and will drill out the ones not needed down the road.
This was an interesting project as it helped me understand how to disassemble a section, repair it and reassemble it. Something I’m sure I will have to do in the future. It took me 18 hours from start to finish to get this done. Not to bad considering the amount of work. I’m glad that’s done and now only have a few small tasks to complete and I’m officially out of work until my fuselage which should be 4-6 weeks away from delivering!!