Apr 02, 2004     Completion of Sides - (5.5 hours) Category: C05 Fus Side

This step really irritated me. The creation of the electrical channel covers should have been a last item in the previous chapter since it has to cure before it can be used. Second, I think the method described is much more complex than it needs to be. I followed the plans at first, then discovered that because of the thickness of the BID layer and the box tape on the plugs my covers were too tall. When you sand the foam in the LWX/LWY/longeron box to make it all the same height the electrical channel cover sticks out above it all. Then you have to jimmy in a bunch of foam around it!

Two hours wasted. I could have cut it down some but had already ripped it out in frustration and since I hadn't carved the foam yet I tried an easier alternative. You can see an original covers and the plug it was made from in the pictures below. Box tape doesn't stick well to foam, and BID doesn't stick well to box tape, so it was really hard to get clean corners, tops, and sides. I didn't. That method took two hours with all the work getting the plugs just right.

My new method went much better (and faster). I created foam plugs that completely filled the box, then carved the electrical channels into them. I left about 2" between the slants for an easy transition/mild bend. I then screed-sanded them to be level with the wood blocks using a long sanding block and a sheet of 50-grit. It makes a hell of a mess but it only takes a few minutes.

Then I turned the pieces upside-down on a sheet of plastic and laid up a ply of BID inside the channel. I let this drape across the flat section to cover the face of the foam that is exposed to the other/lower/outer half of the electrical channel (so I don't punch holes in it while running wires). Total time spent was 30 minutes, counting foam shaping. The extra layup at the top of one picture is just some BID scraps that were too small to use for tapes. I used some excess epoxy to lay them up in a small rectangle for some future use - maybe an instrument panel hole cover or something.

I did one thing really wrong, though. When it came time to trim the sides I found the the foam was short by 3/8". Nat said I could just 5-minute some foam back on and call it a day, so that's what I did. Phew. I did all the trim work but I didn't cut the holes for the spar yet - it's so easy to do with the Fein that I want to wait and make sure it's perfectly lined up.

  Apr 01, 2004     Lower Longeron Installation - (4.5 hours) Category: C05 Fus Side

Again, my system is still having hard drive issues so no pictures posted yet, but I've taken them so they'll be up shortly.

This step was fairly straightforward once I looked at other builders' sites to see how things were supposed to go together, but the wording in the plans sure was mysterious! I had a few issues here and there. First, despite being very careful with the kerfs on the lower longerons, I heard a few cracking noises as I put things together. I sloughed some flox into each kerf once the layup was done so I doubt there will be trouble, but if I had known exactly how this step was going to go I would have steam-bent the wood.

This is a really straightforward process and doesn't even require steam. If you have hot enough water (I can tap the furnace drain for a 180 degree feed, just have to let it run a bit to get clean) you just hot-soak the section you want to bend for about 10 seconds, take it out, bend it and hold it a little FARTHER than you want the bend, let it cool and dry, and the wood will hold its shape. It's a good idea to clamp it down for a day to completely dry out and get back to the same humidity level as your shop - you don't really want all that moisture trapped in the longerons - but you don't even cover them in this chapter it's not hard to do. Believe it or not, if you do have access to steaming-hot water (even a kettle-full is fine) this is actually faster than making all the darned kerfs. Oh well. Don't blame me if you try it and it doesn't work - I didn't actually DO this. Just wish I had.

I also made an executive decision on the BID tapes, and used one tape on the inside corner between LWX and LWY, rather than two. There's no trick to this. You just set up a BID tape long enough to span both lengths, then cut about halfway into it right where the corner will go. The top half bends around the corner, and the bottom pieces overlap in a triangle. It's theoretically stronger than two separate tapes, not that it matters. It was just faster.

  Mar 30, 2004     Inside Layup and Upper Longeron Installation - (9.5 hours) Category: C05 Fus Side

I must have a wider roll of UNI than Nat did when he wrote the plans because the plans clearly show 4 passes to cover the sides at the 30-degree angle and it only took me 3. I double-checked the angle twice to be sure, but it was correct. Suits me fine. To make this less messy I didn't wet out the first layer before putting on the second. The MGS I'm using still wet out the fabric really well (of course, it was 106 degrees at the time!) and I was very careful to spend a lot of time eliminating all air bubbles. This makes it much easier to lay out the second layer. It only works for about two layers at a time, and it helps if your micro is a little wetter than average. This won't make a resin-heavy layup, because the bottom fabric layer wicks out the excess epoxy.

I love it - "This step should take you about 3 to 4 hours." Well, I'm up to 6 hours already and I haven't even installed the horizontal UNI on top of the longeron. The first big layup is a real education. I went through 6 cups of micro and 10 cups of epoxy. I did one thing right, though - I used almost entirely Slow hardener and even so I'm lucky I decided to stippled as I went because the beginning of the layup was setting up by the time I did the "bubble check". I'm still glad I use a digital scale and no pump. The mixing steps gave my arms a chance to rest from stippling. It's only two layers of glass but they're HUGE.

Unfortunately, I ran out of peel ply during this layup so I laid on a bit thicker coat of epoxy in the areas that will need sanding later, to avoid damaging the fibers.

I'm actually a little unhappy with certain aspects of the plans. This section makes it very obvious that some background in both composites and pusher construction are expected, so Nat sometimes overlooked the skill sets of new builders. For example, laying this whole thing up at once was a real pain in the butt, but there was no need for it. It would have been perfectly acceptable to lay up one side at a time, letting the excess fabric from each side hang down into the channel between the sides, for a later knife trim. (The upper longeron makes a GREAT guide for a long razor blade.) Moreover, as you work air bubbles out of one side you tend to pull on the UNI fibers and this affects things on the other side. I had a number of areas that lifted up and left me air bubbles no matter how hard I tried to get it all to lay flat. It took some time to fill and it was all unnecessary.

I did do one thing different that I'm happy about. I didn't run wood block spacers between the longerons during the layup. Instead, I masking-taped some small spacers just at the tops so I didn't have to cut the layup between, then knife-trimmed it after the fact. The Fein and a hacksaw blade cleaned up the few rough spots this created. This was a heck of a lot easier than trying to stuff a wax-paper-covered spacer down between the two top longerons without disturbing anything.

I haven't posted pictures for this section yet because my hard drive is having issues and I don't want to download them from the camera. I hope to post three. The first is a shot of an air bubble area in the strake cutout section that I don't intend to fix. It's not really a bubble, but more of a delamination. Still not good. The second is me standing the instrument panel on its side to get a feel for the space inside the fuselage. It fits really well against the longerons and side so I'm happy about that. There's a gap on top of the longeron itself but this is no problem; I hadn't put the four UNI layers on yet. Finally, there's a shot of me cutting the four UNI strips that help hold the longerons against the sides. This is the beauty of the rotary cutter - this is a 102" long roll of UNI and I counted 24 layers in the roll. Try doing THAT with scissors! Fiberglass stromboli, anybody? I still have a few air bubbles that I didn't fix, but since these are in the strake cutouts I don't intend to. Moving on...

  Mar 27, 2004     Cutting Jigs and Laminating Longerons - (4.5 hours)       Category: C05 Fus Side

Materials were ordered with the parts for chapter 4. However, I discovered that some new items were needed:
1/8" sheet tempered hardboard
1/4" sheet plywood (for last step Chapter 4, I bought it with this batch of materials)
Two pieces 1"x8"x8' pine board

Cutting the jigs was a pain because I have no bandsaw and my jigsaw is broken. I did all possible cuts on the table saw and miter saw, but had to resort to handle tools for most of the cuts. I normally enjoy such work, but the curve on FJA got old by around the third copy. I should have used my router and a template bushing. Anyway, I switched to a Sawz-All and metal-cutting bit and that made quick work of this step with a surprisingly smooth edge. It's only pine, after all.

I haven't built the second of my two workbenches (see Chapter 4) and my temporary table is warped and the wrong height. Here's another ideal task for a $5 sheet of drywall. It makes my 6' table 8' long, and it's all but disposable (heck, it costs the same as hardboard), although I've covered it with plastic to avoid marring it. The first layup will hang out about 3" off each end, but the jigs are stiff enough to tolerate this. I'm delaying making the second workbench to summer, when I move the project into the garage.

Gluing up the longerons went per the plans, minus the tedious nails. My woodworker's instincts told me to use yellow glue between the longeron strips but I resisted and stuck with the instructions. I ended up double-coating each strip because the MGS soaked in so well. The second picture shows some of the clamps I used in my dry run. Always do dry runs to make sure you won't run out of clamps!

I didn't realize what people meant by moving the F28 doubler back a half inch to allow for F28 itself being moved back until I had finished this step. Fortunately the glue-ups hadn't cured yet so I was able to remove the nails and slide it down. I wasn't sure exactly how far to move it, so I eyeballed it at about half an inch and I'll trim it later if I have to.

Unfortunately, when I installed the 15.5" doublers one of them crept down below the longeron a bit (about 1/16"). I had to use the Fein to trim flush, which worked great so no real complaints.