Fuselage

Not the most productive weekend – had a lot going on yesterday, and then I apparently somehow injured my ankle and could barely walk this morning, so I spent half the day in bed. But it got better enough for me to get some work done by the afternoon. First, I drug the aft bottom skin out of its storage spot and out into the driveway. I wasn’t looking forward to dimpling this thing, but really, most of the holes were along the edges and thus accessible with a squeezer. I only had to drag out the C-frame for about 30 holes or so.

Then it was time to wrangle that thing into place. Again, this was not a task I was looking forward to; when I installed this for match-drilling previously, it took forever to get the forward end lined up. This time, though, it actually went a lot better. After some initial frustration, I finally figured out where the major problem was – the right mid side skin, where I curved the skin around the bottom of the fuselage, was actually a bit flat in the middle, creating a point where it wanted to bind against the aft bottom skin. I was able to pull the mid side skin out of the way enough to slid a small zip tie into the spot where the binding was occurring, and that allowed me to get the aft bottom skin in place surprisingly easily. Then I just had to install a boatload of clecos all up and down the thing.

That just left the forward side skins to install. First, I needed to rivet some nutplates to the stiffeners/angle mounts for the throttle quadrant and console. Then, these angles needed to be back riveted to the forward side skins before they were installed. So I got out all my back riveting stuff, pulled out the forward side skins…and realized that the inside surfaces needed to be primed and painted first. And here it was nearly dark already. ARGH!

Instead of my usual wet cleaning/scuffing routine, I scuffed the skins while dry and gave them a good acetone wipe down. This was a lot faster and gave me time to at least shoot primer on the skins before it got dark, but the paint will have to wait until another day. Maybe I can bail out of work a little early tomorrow and get the paint done before dark – such is one benefit of long summer days.

I’ve also got to seal the forward side skins to the firewall edges when they’re installed. I dug out my tube of Fire Block 2000 with some trepidation – it’s been sitting since I sealed the forward floor to the firewall about a year ago, and I was concerned it might have dried up. There was indeed a nice plug of dried stuff in the nozzle, but I managed to clean it out and get the stuff flowing again. So now I just have to get that painting done…

Finally, I got Josie to come help me manhandle the fuselage off the big sawhorses and onto the two purpose-built ones. This support the fuselage much more securely, though I don’t know how well it’s going to work once we get started riveting. Most people invert the fuselage for that job…if I do that, I may have to build yet another set of sawhorses. Something else to figure out…

So anyway, here’s the fuselage in its almost-totally-clecoed state:

So this actually covers work done last night and tonight. Somehow I managed to forget to even write a blog post yesterday…

Yesterday I left work a bit early, just so I could shoot paint on the forward side skins. I taped off the area where it’ll mate with the firewall, since that will get a bead of sealant when it goes together. I also shot paint on the forward baggage bulkhead assembly while it was out of the plane and I was in a painting mood.

Tonight I back riveted the stiffeners and various mount angles to the forward side skins. This was pretty straightforward work, and initially I figured I’d go ahead and install the skins on the fuselage. But then I got to looking at the hole on the left skin where the fresh air intake duct mounts. It seemed far easier to glue the air scoop in place with the skin sitting on the bench, so I decided to do that.

Many guys glue the scoop using Proseal leftover from the tanks, but I tossed the bit of leftover I had some time ago, so that wasn’t an option. Several builders had perfectly good results with JB Weld, so I decide to do that. But first, I had to position the scoop and clean the paint off the mating area on the skin. That took a bit of trial and error followed by some elbow grease. I wish I’d thought of this before I painted the skin; I would have just masked this area from the beginning and saved some work. Oh well.

Finally, I had the cleaning and scuffing done:

Now I just had to mix up the epoxy and glue the scoop on. Except…um, where’s my JB Weld? Oh yeah, now I remember – last time I organized the tool cabinet, I found the tubes were leaking and so I tossed them in the trash. Whoops.

So that was pretty much the end of work for the night. I guess I’ll get some more epoxy on the way home tomorrow and glue the scoop on then.

Well, this barely even qualifies as a work session, but hey, I did do stuff. I picked up some more epoxy on the way home today – this turned out to be helpful after all. The JB Weld I was going to use originally would have been dark gray, but I was able to get some clear stuff. This way, if there’s any excess that squeezes out, it won’t be obvious and ugly.

Anyway, back home, I cleaned the surfaces one last time, mixed up some epoxy, applied it to the perimeter of the vent, and stuck it in place:

Then I weighted it down with – what else – a jug full of clecos:

Aaaand that’s it. Tomorrow I figure I’ll apply the firewall sealant to the forward side skins and cleco them in place. Then it really and truly will be some for some riveting.

So this is kind of a milestone. Tonights work session makes it an even 1000 hours that I’ve put into this project so far. I even went so far as to take a special photo of tonight’s last rivet, the 1000-hour rivet:

Anyway, tonight’s goal was to get the forward side skins clecoed in place and maybe a few rivets shot as well. Before the skins can be installed, though, the joint between them and the firewall flange must be sealed. The other night, I dug out my tube of Fire Barrier 2000 and cleaned out the dried stuff in the nozzle – or so I thought. In truth, I ended up spending another half-hour or so digging crud out of the nozzle before it finally started to flow freely. Only then was I finally able to lay a thin bead along the firewall flange and put the skins in place. This joint won’t actually get riveted for some time – when the cowling is fitted and the piano hinge is installed for the joint. So for now I just clecoed every hole to get a good clamp while the sealant cured (visible at the left part of this photo):

Next up, there are a few blind rivets at the bottom of the forward and mid side skins where they sit atop the center section bars. The corners of each skin have to be pulled out to get these blind rivets set, so that’s done now, while adjacent clecos can be removed to help out:

I actually got a bit concerned after setting these rivets – turns out I was only supposed to do the two in each mid side skin. At first I thought the forward bottom skin might sit in assembly here, but upon closer inspection, that doesn’t seem to be the case. I think having the blind rivet will just make it a little more difficult to get the bottom skin edge in place between the forward side skin and the lower longeron. I’ll poke around the instructions a bit to confirm – I can always just drill those out tomorrow if I have to. I’d rather not, though, simply due to the danger of drilling too far and into the are, which would be bad, bad, bad.

Finally, I began setting solid rivets along the top of the forward side skin. Most of the rivets between the skin and the upper longeron are also in common with the forward top skin, and so they’re left open for now. Only a small number of keeper rivets, which will lie under the top skin, are set. Most of these I was able to set with the squeezer, but a couple required shooting. No big deal.

Tomorrow I’ll start shooting lots and lots of rivets between the forward side skins and the understructure. I was thinking there would be a lot of two-person riveting for the fuselage, but now that I look more closely, I think the vast majority of these rivets I can shoot solo. Only the rivets on the bottom of the fuselage are going to require two people, I think…well, maybe a few others in odd places as well. But in general I feel they’ll be the exception, not the rule.

This will be a straightforward post. I did basically nothing but riveting today, mostly on the forward side skins. I took care of most of the rivets through the gear weldments, the auxiliary longerons, and the joint with the mid side skins, including the rivets through the forward center section bulkheads. I also squeezed the keeper rivets through the upper longerons, but here I did the rivets all the way from the firewall to the tail. No reason not to, plus they provided a nice break from some of the contortions required for shooting the other rivets.

I initially skipped the rivets through the gear tower side flanges, because when I checked the rivets called out in the plans, I felt they were too short, and there were nowhere near enough of the next longest ones to get the job done. So I was going to just order a bunch of the longer rivets, but later in the day, I checked the length again, and while they were a touch short, it was nothing show-stopping. So I guess I’ll use the called-out rivets after all…tomorrow.

Over the next couple days, I think I should be able to finish all the rivets that can be done solo, then I’ll have to recruit Josie for some of the more obnoxious ones. But I’m hoping to have all the riveting done by next weekend.

I also couldn’t resist doing another one of those mostly-pointless temporary assemblies just so I could cackle at the airplane-looking thing I’d created. I put the windscreen frame in place and clecoed the forward top skin in place, then added the setback support for good measure:

So this weekend has been kind of busy, and I haven’t had as much time for airplane work as I expected…but it’s kind of OK, because I’m discovering that this riveting work is kind of physically trying. The combination of bending over and frequently reaching down into the fuse while handling the rivet gun and the bucking bar…well, my arms get tired pretty quick, and then I try to stand up and my back has some unkind words for me. But I’m making it through…

Today I shot the last remaining row of rivets through the aft center section bulkheads. Then I shot all the rivets from the forward side skin to the left gear tower – I decided that the -5 length rivets were OK after all. Finally, I riveted the junction of the left mode side skin to the aft side skin. This was a fun spot – the instructions say not to rivet the rear armrest until after this junction (which also included a bulkhead) was riveted. I understood why once I got to it – there’s one rivet that is impossible to buck with the armrest in place. The armrest has to be unclecoed and swung up out of the way. Once the bulkhead was done, I riveted the armrest to the skin.

Finally, I moved back to the aft side skin and riveted the next two bulkheads. This still leaves the two aft most bulkheads, but at this point I felt like it was time to call it a night. I’ll probably need two more evening work sessions to get the right side of the fuse to the same point, then I’ll have to decide whether to try some of the more difficult rivets solo, or if I should flip the “canoe” and get into two-person riveting mode.

In the meantime, here’s the left side of the fuselage, mostly devoid of clecos:

Short night tonight – I just shot all the applicable rivets in the right-side gear tower. Those were the most obnoxious rivets left that I’ll be shooting solo – the remaining solo rivets are all -3s and thus not nearly as tough. So the next work session should be riveting the armrest/bulkheads/etc on the right side.

Aaaaand that’s all. Nothing really worth photographing tonight.

Well, I thought I’d get through the rest of the solo riveting tonight, but it didn’t quite happen. I started out working on the bulkhead just behind the rear seat, which has a double row of rivets. First off, it was kind of uncomfortable shooting those due to lots of bending over and so forth, and second, I botched a couple rivets and had to drill them out. One of those, I opened the hole a bit, so I got to do a good old NAS rivet instead. Once I’d finished the bulkhead, I riveted the armrest to the skin.

At that point, I could have either done more bending over and riveting, or shot some paint instead, and I chose the latter. You see, despite my best-laid plans to try and prime and paint all visible surfaces before beginning final assembly, I overlooked that bulkhead, which will be visible to the sides of the rear seat. Not a whole to be done here except to prime and paint it in place.

I couldn’t do my usual thorough scuff and prep here, so I just did the best I could. Then I masked off the floor and tailcone area to prevent overspray (not strictly necessary, but hey…I’m a bit OCD I guess):

Then I shot primer before going inside for dinner, giving it about an hour to dry (it doesn’t take long in the Houston summer heat). Then I went back out and shot the topcoat. Here’s the finished product after removing all the masking:

Looks good to me!

Again, not much to report tonight; I just shot the rivets in the right aft side skin through the bulkheads. The two rearmost bulkheads still aren’t riveted to the aft side skins, though – I’m kind of eternally putting those off. It’s pretty tight quarters back there and those will definitely be challenging.

Pretty soon it’s going to be time to flip the fuselage over so we can start shooting the rivets on the bottom…

I’m starting to wonder just how many parts there are going to be in the “fuselage riveting” series. Of course, when I’m doing mostly short work sessions, it’s somewhat unavoidable…

Anyway, tonight I worked on riveting the aft side skins to the two aft most bulkheads. Space is pretty tight in this area, so it was kind of slow going – but I managed to not mangle any rivets, which was nice. I also discovered that there were some more rivets between the aft side skins and the upper longerons that could be squeezed – these are at the aft end, further back than where there will be rivets in common with the turtleneck skin.

I still have some rivets on these bulkheads left to do, though. On the forward side of one bulkhead are riveted the two large bars that the horizontal stab will attach to. These bars are very much in the way of bucking the skin rivets. I was able to shoot the bottom three rivets on each side – the bars are angled away from the skin here, so access is OK – but I stopped there. None of my bucking bars will fit in the tight space from here on up, so I’m going to have to get creative. I’ve heard of guys using axe heads, chisels, and so forth as ad hoc bucking bars – really, anything that has heft and a smooth surface can do in a pinch – so I’ll see what I can come up with. Then maybe I can finally turn this thing over and start working on the bottom rivets…

Here are a couple photos of the tight space created by the stab attach bars. At the top, there’s maybe 1/4” between the bar and the bulkhead flange: