Dave’s RV-7A Building Log

I did a little Scotchbrite work on the HS rear spar doubler. There was one spot on the surface that was particularly pitted. I tried sanding it out with the wheel. It did an acceptable job, but now the surface is uneven. I’ll end up going back over it with course/medium/fine on the palm sander. I’m basically just tinkering around waiting for the replacement parts. If it looks like they will not arrive by the weekend and the sprayer still isn’t here from Harbour Freight, I might start in on the VS.

The Scotchbrite wheel finally arrived, so I spent some time playing with that on some scrap. I also tried deburring some of the ribs with it. It works fairly well. I think because the wheel is so new, that’s it’s still fairly aggressive. Running the edge of the rib at a right angle to the wheel produces makes the edge nice and smooth but produces a bit of a burr on one side of the edge. That seems to come right off with a Scotchbrite pad. I’ll keep playing with it until I get it right.

I also spent a little bit of time sorting tools and finding new homes for things. I still need to make more room. There’s no way the HS is going to fit on the bench right now.

I spent most of the weekend at a Y Princess camp out with my daughter. I did get in a few hours on the project on Sunday afternoon, which was unfortunate as you’ll soon see…

My first major screw up. I dimpled HS-702 and countersunk HS-710 and HS-714. I made extra double sure that I was dimpling and countersinking the right side of everything. That went fine. I think my problems started with the dimpling. I think I dimpled HS-702 too much. I started with a shallow countersink and kept adding a 1/4 turn to the countersink depth each time. I got to a point where the dimple disappeared into the countersink, and that’s where I should have stopped. I could never get the skin to lay completely flat, I think because the pneumatic squeezer warped the surface of HS-702. I kept going deeper and deeper with the countersink to the point where it was obvious I had gone way too far. I could call Van’s and see if there is some work around. However, this is right at the attachment point of the HS to the fuselage. I don’t want that area comprimised in any way. At this point, it’s fairly easy to start over with a new HS-710 and HS-714. Since HS-702 is match-drilled to those pieces and I figured out that I drilled the holes past the bend when I wasn’t supposed to do that until the last step, I decided to get two new HS-702 pieces as well. So $80 and 4 hours of work wasted. Not too bad. I just need to be more careful until I get all of the tools figured out. That will be especially true when I start riveting. As things get put together, it will be more and more difficult to fix mistakes.

After that, I took it easy. I de-burred some ribs. I measured out and marked the holes for the forward end of HS-405. After the screw up, I didn’t want to make any more mistakes for the day. I spent about an hour reading through the rest of the instructions for the HS, laying out the pieces and figuring out where everything fit.

Started working on the HS front spar. Shaped the ends of the HS-710 and HS-714 reinforcement angles. I did that on the bench sander, but it would have been much quicker to do some initial cuts with a band saw. Final drilled the reinforcement angles to the spar, then bent the 6 degree bend on the ends with a vise and hand seamer. Cut the extra flange off of HS-702. I followed the directions and drilled the #30 hole then used the Unibit to make a 1/4″ hole. That worked really well. From there I used the spins. I tried to straighten out the little bit of bend that was left over. I went back to the bench sander to smooth the sharp corners on the cuts. After that I put the 6 degree bends in the ends with the vise and some blocks of wood. Then I clecoed the pieces together and read further on in the instructions.

I didn’t think I would get much done last night, but it was a productive session. I can’t wait to work on this thing for more than an hour at a time–next weekend. During the week there are too many things going on, especially since I’m flying twice after work this week. I’ll probably go back to one lesson after work per week soon.

I final drilled the HS rear spar reinforcement bar to the rear spar. I couldn’t wait to try out the debur tool in the cordless screwdriver, so I deburred all of the holes. Of course then I final drilled the hinge brackets to the spar and enlarged the holes for the middle rib. I’ll have to go back and debur those again. It’s probably better to do all of the trial assembly and drilling at one time, then mark everything, disassemble, and finally debur.

Despite my prior complaints about the air cleco tool, it’s awesome. I was able to move and remove clecos with ease and much faster than without it. Definitely worth $25.

I stopped by Lowes on the way home and picked up a bench mounted belt/disc sander for about $90. I rounded the ends of the second HS-609PP in about 5 minutes with that sweet machine. The same thing took over half an hour last night with a Vixen file. Considering the overall cost of this project, $90 for a power tool that will save me dozens of hours is well worth the cost.

I also dug out my palm sander and put on some 120 sandpaper to sand out the milling marks on the faces of the HS-609PP. That worked pretty well. I definitely need some more durable sandpaper. The white aluminum oxide paper doesn’t last long. There was some resin coated paper at Lowes that I’ll pick up. After the 120, I switched to 220, and then the Scotchbrite pads. Getting the right combination of steps is going to take some time, but I’ll figure it out. Once the Scotchbrite wheel shows up Monday, that should help as well.

Both of the pieces are looking sweet now. They’re ready for drilling to the rear HS spar. And then deburring. And then priming. And then, finally, riveting.

Received the primer/sealer from Aircraft Finishing Systems. They shipped it out very fast. I also received the $25 pneumatic cleco actuator I ordered from The Yard Store. I’m figuring out that you get what you pay for. It’s not a pretty tool, especially compared to the Sioux drill. It does seem to work, but leaks a fair amount of air if you don’t hold the trigger just right while the cleco is actuated. I’m pretty sure it will do the job.

Page 1, step 1: shape HS-609PP. Since the Scotchbrite wheel is backordered, I started in on it with a Scotchbrite pad. I’m definitely going need something more aggressive to get out the milling marks. I used the Vixen file to round off the end. That went ok, but was a bit time-consuming. Maybe the bench grinder or a bench-mount belt sander would make that go a little quicker. I’ll look around on other sites and see what others have done.

On the way home I picked up a few items including this handy tote for storing the clecos. I drilled a hole in the top to store the cleco pliers. I got this idea from somewhere, but I can’t remember where right now.

I didn’t put too much time into it, as I had a flying lesson (10 touch-and-goes at Boeing Field, whew!) and spent some time clearing a space on the bench.

I spent some time inventorying and sorting all of the little bolts, nuts, washers, rivets, and other stuff into the organizer. I used a wipe-off type pen. Probably should use something a little more permanent. I don’t want to lose track of what everything is.

The Cleaveland tool kit should arrive tomorrow! Then I’ll really get started!

The second box arrived with the big stuff. This box was much more impressive. I think I may invest in whatever company Van’s is using for duct tape. They must have used a roll of it on my box alone. It keeps things very secure, but made it a little hard to get the tape off of the skins without removing the protective blue plastic.

I spent about an hour unpacking everything and inventorying the bigger parts. I separated everything by section (rudder, elevator, etc.).

Julie insisted on a goofy picture with me and the “high dollar aircraft parts” box. And of course Leo had to get in on the act.

I also spent about an hour studying the steps and plans for the horizontal stabilizer. Doesn’t look too bad. I just need a bench grinder and Scotchbrite wheel in order to get started working on the parts.