Dave’s RV-7A Building Log

I took the canopy out into the driveway and shot a coat of primer onto the fairing area to see how it looked. It’s amazing how areas that seemed smooth turn out to be really wavy. I have some more work to do still. Part of the problem is the difference in density between the microlight filler and structural filler. They aren’t sanding down at the same rate, which is causing some uneveness.

I continued working on the F-704 covers. I drilled all the holes to full size and deburred everything. It was really fun to do some good ol’ metal working again. It’s been quite a while since I’ve done drilling and deburring. I also pulled out the swivel cockpit lights I bought a while back to fit those to the covers. Looks like I need to drill a couple of 3/4″ holes. But before I do that, I wanted to make sure the lights weren’t going to interfere with the canopy latch keeper. I installed that with the spring. The rod the spring rides on sticks way into the area under the left cover, so the light needs to be below that. The keeper isn’t moving as smoothly as I would like. Hopefully that loosens up over time.

Yesterday after work I finally got back up in the air again. I took a 172 up with an instructor to knock off the rust. It went surprisingly well. I’m cleared to rent the school’s planes, so I’ll be flying more often now.

Adele had a soccer game, so I didn’t have too much time for the project. The 48″ throttle quadrant cable I ordered from Vans arrived yesterday. I used some boards to hold the throttle quadrant in approximately the correct position (since I still don’t have the panel back from Ross yet). I test fitted the cable and the length is perfect for the prop. The throttle and mixture cables ideally need to be about 2″ longer. I could make the 48″ cable work by ordering the cable extensions from Spruce, but I’ll just order custom cables of the correct length.

The only problem is the diameter of the cable. It’s almost 1/10 inch thicker, so it won’t fit through the eyeball fittings I just drilled to the firewall. The instructions for the fittings say I can drill them out, but I’d have to drill them so large for this cable that there’d be nothing left of the sleeve that holds the cable. Argggg! It seems like every time I turn around there’s a new hassle. I’ll see if the custom quadrant cables from Spruce have a smaller diameter.

I worked on the covers for the F-704 sides for a while. I left these off to allow for wiring up some lights. I’ve had the lights for a while, but just haven’t gotten back to it. I deburred the covers and clecoed them in place. Well, the right one wouldn’t fit. I apparently installed the right canopy deck about 1/32″ too far forward and it prevented the cover from slipping into place. I spent quite a bit of time sanding and filing and finally got enough clearance.

The microlight filler is much easier to sand. I sanded down the canopy fairing starting with 80, then 100, then 150, and then 200. The shape looks great. I found that feeling the contour was a better indicator than looking at it. I kept sanding it little by little. I would try painting some primer on it, but the wind really kicked up today. I’ll wait on that step.

I was planning on installing the latch fingers. Thus, I installed all the canopy latch hardware. I’m not sure why I didn’t install these before. I guess I painted them and then never put them in. Installing the mounting points for the gas struts was really tricky. A little EZ-turn helped out. That stuff is super sticky. I used that to stick the washers and nuts to the tip of my finger while I turned the screws. I didn’t install all the cotter pins yet. They’ll be tricky, and I’m not sure if I’ll need to remove them again anyway.

I think I finally have the cabin heat muff figured out. I’m going to have a custom muff made. I’ll feed the fresh air into the bottom of the muff.

The outlet will then point aft where the SCAT is positioned in this picture.

The tubing will then fit between the intake tubes and sump. It’s tight in there, but I can secure the SCAT to the oil return lines. I think it will work out quite well.

I also messed with the breather tube. The angle oil adapter interferes with the standard route. I think using a straight section of the radiator hose, I found a route that will work. It might requre a little tweaking of the bends in the tube.

I hadn’t planned on spending so much time on the plane today, but I got a lot done. It’s nice to see the interior coming together.

I spent a heck of a long time sanding down the filler. I wish that I had just used the microlight filler. It’s much easier to sand. I also wish that I had been more careful about squeezing the excess from the top edge. Sanding along that line without going right through the electrical tape was very time consuming. I eventually got it sanded down to a decent shape.

I ended up removing the electrical tape, as I was worried that I had sanded through it in a few spots. Turns out the tape was fine. I replaced it with another double layer of tape.

I mixed up a batch of microlight filler and smoothed that very carefully over the fairing area. The nice part about the microlight is it tends to self-level. I learned how quickly epoxy can flash. I had quite a bit extra in the cup and it turned into a ball of smoking epoxy. I’m glad I noticed it before it melted through the cup.

Leo decided I was spending too much time on the plane and not enough with him.

While the epoxy set up, I went back to installing the control cable eyeballs. I enlarged all the holes to 1-1/8″ and made a new hole for the alternate air cable. I used the template for the eyeballs to drill the 6 little holes. On almost every one, I had to file a little bit to make it fit correctly. The eyeball for the mixture was especially difficult to work on. I had to crawl inside the cockpit for that one. It’s great to have the eyeballs installed. As soon as I get the control cables figured out (and the panel back from Ross), I can install the quadrant and cables. The far right hole in the second picture is for the alternate air.

I mixed up a batch of black dyed epoxy with the West Marine structural filler. I applied that to the fairing area and smoothed it out as best I could with a plastic squeegie thing I had around. This filler is definitely not smooth. It has more of a pebbly surface.

I decided to work on installing the control cable eyeballs. First step is to enlarge the holes to 1-1/8″. Previously, I borrowed a punch from a friend, but the 1-1/8″ punch is not as expensive. I went ahead and purchased one from Spruce last week. It works pretty well, although it leaves a nasty burr. A sanding drum in the Dremel cleaned it up easily.

I put down a couple more layers of fiberglass on the canopy fairing. The first few layers went well. Then I decided to try cutting the fiberglass on a diagonal bias. That makes it much more difficult to work with. It turned out OK. For the last layer, I laid the fiberglass right over the clips. Thus it has some bumps and depressions here and there. Nothing that can’t be filled and sanded out. It’s a little hard to see what’s going on in the blurry picture, but the fiberglass (dyed black) is almost right up to the black electrical tape on the canopy. (Caught Adele talking on the phone in the background.)

I’ve never seen a good picture of how people deal with the side. I laid just the final layer onto the side skirt. If you put too many layers onto the skirt, it will be a big bulge.

Last night Adele had a soccer game, and I didn’t get much done tonight either. I sanded the canopy fairing a bit. After 3 layers of fiberglass, some undesired bumps were developing. I sanded the whole thing so the next layer will stick well, and sanded down the bumps.

I’ve been working on a bunch of other stuff related to building. I ordered an angled sniffle valve, a Piper part, from Mattituck. I called Rick Robbins who makes the cabin heat muff for Vans. He can customize the length and angle between the inlet and outlet. I messed around with the SCAT tube a bit to see if I could find a routing for it inboard of the intake tubes.

I placed an order with Vans for a 48″ throttle quadrant control cable. I’ll try it out and see if that length will work for the throttle, mixture, and/or prop. If not, I can custom order the lengths I need. However, the custom length cables cannot be returned, the standard 48″ cable can.

My order from Pulsar arrived. They sell a very unique system for applying labels to a surface. It’s definitely a tricky process. I did a test run with one of the logos they include and had some lifting. I think I used too much adhesive. I’ll practice some more, but I think this will be an excellent way to label the panel.

No more excuses. Time for some fiberglass work. I mixed up a small batch of really dry epoxy and microlight filler. It was about the consistency of peanut butter. I used a zip-loc bag again with the corner cut off to apply it along the forward edge of the canopy where the previous batch of filler sagged a bit.

Next up was a double batch of black-dyed epoxy and a large sheet of fiberglass. After spreading the epoxy out, I cut the fiberglass into 1/2″, 3/4″, and 1″ strips just the right length to fit between the hold-down clips. Having dyed epoxy makes it a little difficult to tell when the fiberglass cloth has completely soaked up the epoxy. I just worked it around a bunch. Didn’t get any meaningful pictures of this part other than this one.

It was actually quite an easy process of applying a layer, smoothing it out with a sponge, and then applying the next layer. At first I wrapped the fiberglass around onto the side skirts a bit. But then I started worrying that I’d have a big bulge there, so I cut off the extra.

I didn’t cut the strips on a diagonal bias. The instructions say it’s not necessary. That’s true for the front center of the canopy. Around toward the sides the strips didn’t want to lay down as nicely, especially the 1″ strips. I’ll cut the next batch on the diagonal bias. Plus that should help strengthen the joint.

All-in-all, it didn’t take long and turned out pretty good. Adele got an action shot with Leo keeping me company briefly as well.

I also received some goodies from Spruce, the throttle quadrant, some special grommets where the ignition wires pass through the baffles, and a few other small items. The quadrant really looks great. I’m glad I went this route, eventhough it’s going to take a few hours of extra effort.

The list of things I have yet to buy/order is getting shorter. Right now the list is:

Archer VOR wing-tip antenna (Spruce)
Additional Commant comm antenna (Vans)
Back-up 2-1/4″ altimeter (Vans)
Back-up 2-1/4″ airspeed indicator (Vans)
Trutrak 2-1/4″ turn and bank? (Stark)
Trutrak 2-1/4″ Digiflight II? (Stark)
Garmin GNS-430 (Stark)
Garmin GTX-330 (Stark)
PS Engineering PMA-8000B (Stark)
Garmin SL-40 (Stark)
CreativAir wing-tip LED nav lights (CreativAir)
Tail position & strobe light (Vans)
Heated pitot tube (Spruce)
Gear leg intersection fairings (Fairings Etc?)
CO detector (Spruce)

I still haven’t decided how to deal with attitude back-up for the EFIS. That’s why I put a question mark after the Trutrak turn and bank. Ideally I’d get a 2-axis autopilot in their ADI or turn & bank product, but they don’t currently offer that in a 2-1/4″ instrument.