05/25/04 (2.25 hours):
Cutting the blocks for the NACA scoop was easy enough, but I screwed up cutting the 2" foam efficiently - I went the long way, not the short way, thinking only one block was to be cut. I just know I'll pay for that move later, but fortunately a sheet of 2" thick urethane is only about $14. I'll order an extra sheet with my next parts order. In the picture below you can see my trust bandsaw (snicker) but it works very well. Even if I had a bandsaw, I could still have made these cuts faster with the coping saw than walking over to a floor machine. When shaping urethane, power tools are just irrelevant. The second photo shows all the bricks it took to get the blocks to conform to the fuse bottom. The bricks on the 1" foam are just for good measure - it bent pretty easily - but the 2" foam is pretty stiff and needed lots of weight to get it to curve.
05/26/04 (3 hours):
Although it doesn't seem like much progress for this amount of time, I got the small triangles floxed into place between the landing gear bulkheads tonight. I spent some time getting things laid out just so, and puzzling out exactly how they would fit. I also cut the C and D pieces as well, although I didn't mount them yet. I have some untrimmed excess flox to remove before I can do that, so I'll save it for the next day.
05/27/04 (4 hours):
Tonight I fitted supports C and D. It took a bit of figuring out and I have a slight gap that I'll have to fill with foam or micro at some point, but otherwise this bit was fairly straightforward. As you move along here you start to see the progression - everything gets filled with urethane to or above the level of the bulkheads so when you're done sanding you have a perfectly smooth surface. Neat.
05/28/04-05/29/04 (3.5 hours):
Funny story, or at least it will be when I look back in a year or two. I spent some time putting together the 3/8" foam pieces between the aft LG bulkhead and the firewall. In the process I screwed up the long horizontal piece, cutting it too narrow fore-to-aft to sit in the hole without support. So I cut another, and began assembly.
Composite construction has a way of reminding you to not get cocky, and I certainly did here. I mixed up a moderately sized batch of flox using all Fast hardener, and got to work sans gloves because I've been pretty successful at keeping my hands clean on "minor" flox and micro work like this, so I'm mainly wearing the full getup when doing large layups, or working with fabric. (Fiberglass itches!) So here I am gluing the foam pieces in and my flox starts to exotherm. Only, I'm not holding the cup so I don't realize it - flox just gets easier to spread when the runaway heat buildup first starts. At this point I had the two side pieces installed, and I've got flox almost completely spread on the large horizontal bit.
The smell and sizzle awoke me to the pending issue, but I figure, hey, I'm basically done here so no big deal, right? I quickly spread a thin layer of flox on the rest of the edges, knowing I can always fix it later - grind a bit off if it sticks up, squirt some new flox into any gaps, etc. I start putting the piece in and realize that because it's so tight I can't get it in at all. Now I've rubbed exotherming-flox all over the place, I have it on my hands, all over the various foam and bulkhead pieces, etc.
I did the right thing, and yanked that piece of foam out of there before it could become permanently installed at an awkward angle. I then spent some time cleaning flox off the bulkheads and properly installed foam side pieces before it could completely harden, cleaned my tools and hands (which itself took time) and quit for the night, frustrated but at least accepting my fate. Remember that undersized piece of foam? The next day I arranged some supports on the insides of the bulkheads to hold it in position, mixed up a fresh batch of flox and put it in a plastic baggie. I cut off the corner and used this to squirt it into the thin gaps I had previously been worried about, and in 10 minutes I had the "bad" panel installed, perfectly. Live and learn. It's not even worth the effort to clean the flox off the old piece. I'll just cut the edges off and use it as scrap material for future work, if I need it.
05/31/04 (4.5 hours):
I had the day off today, but got very little done. I started cutting the aluminum hardpoints for the landing gear cover but cutting 1/4" aluminum is tough, and I got frustrated and stopped. I'll buy a bandsaw tomorrow and that should make short work of this job. I did manage to get the scoop sanded and shaped, though, so at least not all hope is lost. I also ordered Vance Atkinson's fuel sight gauges. Unlighted, since I don't feel the $30 price different for lighted gauges is justified - for $1 I'll add the LEDs myself. I don't actually care about sight gauges since I'll be using capacitive fuel senders, but I suppose it'll add to the value of the plane, and it's a nice backup.
06/01/04 (2 hours):
Today I shopped around and bought myself a bandsaw. Just a cheap 9" table-top unit, but it's actually pretty decent. I also bought a few additional blades, a metal-cutting blade among them. Band saws are amazing. Unlike a table saw, you can safely free-hand jobs through them, and they don't even know what you're cutting. They just go right through it. The blade doesn't even get warm. It took a bit of time to cut all 16 of the little metal hardpoints, but only because I wanted to be as safe as possible and arranged push sticks and guides to make sure my hands didn't get near the blade. The actual cutting took less than a minute. In contrast, it took nearly 10 minutes to cut JUST ONE by hand with a hacksaw.
06/03/04 (2.25 hours):
Yesterday I took a few minutes to alodine the landing gear cover hardpoints but didn't get any more done than that. Elliott hasn't been sleeping very well, waking every hour or two, and it's been torture for Nicole to deal with after she goes to bed. I put him back in the sling last night and he still woke up quite a bit but never for more than a few seconds, just to make sure he wasn't alone. He's not in any pain or discomfort so it's probably fear. We'll try putting him back in his cosleeper for a few weeks, and instead of having him sleep the whole night in his room, we'll have him sleep part of the time in each spot, then gradually phase him back to his room completely.
Anyway, because I had him in the sling I couldn't get anything done, but today I managed to take a few minutes over lunch to route out the holes they're installed in, fill with flox, hammer in the hardpoints, and smooth out the squeezed-out flox. I hammered one of them in slightly below the surface accidentally but I covered with flox and overall, I'm pleased with how it turned out.
Another builder pointed out to me that Wayne Hicks came up with an easier method. Instead of installing hardpoints and routing out a lip for the landing gear cover to sit ON, he installed tabs on the sides of his landing gear well (on the aft side of the forward LG bulkhead, and on the foreward side of the aft LG bulkhead). He then shaped his cover to fit INSIDE the well, with its top flush with the surface. This eliminates the need for the hardpoints (you install ClickBonds or similar on the tabs) and also the pain-in-the-keister 1/8" lip that is so hard to keep the glass lying flat in. Unfortunately, I had already routed this lip out when I was pointed to Wayne's site, so I went ahead with the plans method. But Wayne has had a number of good ideas (I used his upsidedown jigging method in Chapter 6, for instance) and I was kicking myself for not stopping by his site for tips and tricks before starting this chapter. Sigh.
06/08/2004 (2.5 hours):
It took some time to clean up the results after glassing. I had too much epoxy in the layup, and it started exotherming as I was laying down the peel ply. What came through the peel ply didn't want to peel off, so I had to sand that down. The Fein does wonders in that score - gets right down to the peel ply without harming the glass below - but it was still annoying. Anyway, moving on.
09/20 - 9/27/2005 (7 hours):
I did a poor job glassing the NACA scoop the first time around. I had a very difficult time getting the glass to lay into the joggles, had a few dry spots, and neglected to wrap the glass onto the bulkheads. I focused some attention on this area because the efficiency of the scoop will be critical to successfully cooling my rotary engine installation.
I started by sanding flush any rough areas, and sanding the entire area. I removed the dry glass sections. Then I filled the joggles back in with scraps of urethane. I will use Wayne Hicks' jogglefree concept for the landing gear cover:
http://www.maddyhome.com/canardpages/pages/waynehicks/chapter_09_5.htm I then re-glassed the area with two layers of BID. This means I actually have four layers, but it's not a huge area of glass, and the ounce or two I'd save by sanding it all down to foam wasn't work the time, energy, and risk of damage to the NACA scoop shape. I now have quality peel ply, and I applied this to the entire area. This both provided a good transition edge in those areas I had removed and helped the glass lay over onto the bulkheads.
I had one small area where the glass came off the firewall. A portion is still well attached, there's just an air bubble/curve where it comes around the corner. I'll fill this with some epoxy at a later step, probably when I glass the bottom.