Dave’s RV-7A Building Log

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.

It’s the time of year when Julie wants to put the top down on the convertible, which means taking the hard top off. The soft top does not like to be outside. It’s wet in the morning, so you can’t put it down. And it’s nice to just pull into the garge in the evening with the top down and leave it down.

Thus, we started a massive day-long clean-up effort around the house involving smashing up the old picture window, picking up various wood and debris around the house, borrowing my in-laws truck, and finally a 1/3 ton trip to the dump. I spent a huge amount of time cleaning everything off the shelves, dusting everything, moving the shelves into the spare room (aka the wing room), and transporting all the various parts into there. There’s a ton more room in the garage now. As soon as I’m done messing with the canopy, the car will fit again.

I mixed up some really stick epoxy with microlight filler and black dye. I cut a corner off a zip-lock bag and used that like I was decorating a cake. I squirted the filler into the crack between the plexiglass and metal. I used a gloved finger to smooth it out until it looked really good. Well eventhough I had the epoxy really mixed up stiff, it still sagged a little bit. I mit apply a bit more filler before starting with the fiberglass.

Did various stuff on the plane today including connecting part of the cabin heat system, from the intake to the muff. I was going to hook the muff to the cabin heat selector, but it looks like it’ll be in the way of connecting up the mixture control cable.

For some reason, I didn’t paint the F-704 bulkhead when I touched up the paint in the cabin a while back. Not sure why. It doesn’t matter too much as I just ordered interior side panels. I decided to mask it off and paint it anyway.

I pulled out the canopy in order to work on the fairing at the front. It’s one of those things that I left unti “later.” Might as well get it done. I could actually completely finish the canopy. That would be nice. It seems like everything is partially finished.

I did the DanC trick of using some small tabs to hold down the canopy. My canopy ended up popping up a bit when I secured the sides. The clips held it down partially. I’ll fill the rest with epoxy.

I masked off a line along the plexiglass that looked good. I did a combination of using a 4″ radius (not 4″ diameter as the instructions indicate) cardboard disk to visual the fairing shape, measuring with a ruler, and just eyeballing a smooth curve. It turned out pretty good. I masked off the metal below as well just to minimize the mess. I sanded the metal and plexi with some 60 grit sandpaper. It’s tough scratching up something I spent so long trying to look perfect. The picture shows an intermediate step where I was using chunks of masking tape to mark the line.

I decided to get the camlocs through the Milspec group buy. I personally don’t like the looks of the camlocs, but they’ll be much easier for installing and removing the cowl. I bought the firewall only kit with the straight slots. The hinge works great on the horizontal seam. I’ll have to drill out the rivets I set for the hinges and put in attachment strips. That’s not a big deal since I messed up the side hinges anyway. I’ll also fill the rivet holes I drilled in the cowl, which will be easy. From what I’ve read, I’ll want to reinforce the cowl along the edge anyway to prevent puckering between the camlocs.

I went on to something different while I wait for the camlocs to arrive. I fabricated a concealed oil door hinge. I thought it might be a little tricky, but it was trivial. It took less than an hour. I’ll write up some details with pictures when it’s all done. So far I bent a piece of .032 sheet into just the right shape and riveted it to a short chunk of left over hinge material. I also ordered a torsion spring from McMaster-Carr. They have about a thousand springs to choose from, but I think I found one that will work well for holding the oil door open.

After enjoying a smoke-free beer at the Roanoke with Steve-o (Washington’s smoking ban is awesome), I didn’t do too much on the plane.

I decided to check the paint gap on the cowl all around one last time. In the process of doing that, I realized I screwed up the side hinges. I attached them one rivet too far down. I double-checked yesterday when I was riveting them on, but apparently still messed it up. The only real problem is that there is one less hinge loop at the top to support the corners of the cowl. I’m trying to decide whether to drill them out and re-attach, or just leave them as is.

After carefully looking at all of the gaps and testing them with a strip of .020, I sanded just a tiny bit more along the horizontal seams. It should be ready to go now. I had Julie document the special occasion.

I’ve also been looking at the Milspec camloc group buy. Those things sure are tempting. I’ve installed/removed the cowl a couple of times now using the hinge pins. The hinges along the horizontal seams are easy to install. The others, especially along the top and bottom, are not easy. With the 30% group buy discount, I could do the firewall for about $200 including tools. Hmm…

I put some high-temp RTV between the firewall and side skin and riveted on the side hinges. It was a little difficult to get the RTV in there. I used a popsicle stick to open up the gap, and a strip of scrap aluminum as a putty knife. Worked really well. The only hinges left to attach to the firewall are along the top. Those will wait until the forward top skin is ready to attach, which is after all the wiring is done–way down the road.

There was a suggestion on the forum about using extruded hinges for the cowl. They are a bit more expensive, but I guess they are less prone to cracking. I’m not sure if I’m going to stop progress and order some of them or not. Some people have had trouble with hinge loops breaking off. A couple of suggestions I’ve read are to make sure the hinges are not pre-loaded and to deburr the corners between the hinge loops. Decisions, decisions.

We went out to the beach for the weekend, but we returned fairly early on Sunday. I managed to do a few things, basically getting over the hump on the cowl.

I countersunk the top and bottom cowl halves in preparation for riveting. I also worked on the paint gap a bit more. It’s now as good as it’s going to get. The sag at the front didn’t get any worse than 1/4″. I’m ready to rivet on the hinges.

Sorry there haven’t been many pictures lately, but sanding the paint gap is just a monotonous task. I’ll have some good pictures of the cowl once the hinges are on.