My wife was out of town for the week, so I figured to get some extra shop time in. I spent a couple of evenings finishing up the prep work for the tanks. My hangar neighbor John was going to help me get started. He was an F-16 crew chief and had some familiarity with the grey goo they call tank sealant. It seemed better to have a go at this with someone who used this before. The Rans Raven he’s building has a roto-moulded tank, so he had it a lot easier!
The tank skins were slightly deformed from sitting out so long. The nose was decidedly more pointed than round, so I did a dry fit of the ribs to see if it would come back into shape. That part worked out, but it was slow going just to get the ribs to line up. I made a rib shaped spreader that helped some and I polished and pointed my bent up 3/32″ pin to make a drift pin. With the ribs in place, the pointy-ness disappeared and I got a good fit.
I still had a little prep work to do on the end ribs. I riveted on the nut plates (used to secure the fuel tank float). They didn’t need any sealant because I’ll form a tank sealant gasket when I do the final install later.
Then I cleaned up the edges of the anti-rotation collars that hold one of the fuel fittings in place. I decided that it would be a good idea to check to make sure that the nut fit into the collar correctly…. It very much did NOT! I had to file and clean the edge quite a bit to get a good fit. This would not have been very easy to do once the fitting was installed on the rib (would likely have had to drill it out and re-mount it!).
That gave me all the parts I needed to get started! In anticipation of John’s arrival (he is SO not a morning person), I got everything prepped and laid out. I pulled the sealant out of the fridge (keeping it frozen or cold prolongs the shelf life), set up the C-frame to rivet the tooling holes closed, and got my dixie cups and popsicle sticks ready….
At this point, I don’t have a lot of pictures because my gloved fingers were covered in sticky grey goo. But I can tell you, it did not go well at all. We started by trying to rivet in the VA-141 fuel flanges. I tried a squeezer, but the rivet set caught on the edge and I couldn’t get a straight shot at the rivets. I tried shooting the rivets instead, but I ended up clenching them AND distorting the flanges. We tried drilling out the rivets, but we ended up messing up the holes. We declared the whole adventure a total loss. I’m ordering new parts from Van’s and we’ll try it again.
So, with that out of the way, we moved on to the really expensive parts! There are 11 stiffeners to install on each skin. You have to make sure that each rivet is well coated in goo before pushing through the holes. We used clear packing tape to hold the rivets in place and back riveted the stiffeners in. This was the first time John had seen back riveting. I like it because I always get such nice, clean rivets. The first 10 stiffeners went really well.
Now all this time it is really raining as a huge storm cell passed right over head (much better building day than a flying day). I closed the big hangar door because the rain was pushing inside. John went next door to close up his.
While he was over there, I set up the 11th stiffener, prepped the holes, taped the rivet line, slipped the stiffener in place…. Then I looked down. There was water FLOWING though the hangar. It was pouring through the bottom of the wall seam and running a half inch deep in places. This was not a good day to have my electrical cords down on the ground!
Then the power went out!
The power came back on again a couple minutes later. I was just prepping to rivet the last stiffener anyway (air powered!) with a headlamp.
So I spent the next hour pulling boxes and electrical off the floor and sweeping water out of the hangar.
I’ve ordered new end ribs and flanges. They’ll come with the fuselage kit that will show up in early August (it also contains a new horizontal stabilizer skin — the old one had a big ding in it from an early back-rivet fail).
I won’t get a chance to get back to the shop this month since I’m taking a trip out west for my niece’s wedding. It will be nice, some day soon, to do those trips in the RV-14! But for now, it will have to be commercial.
When I do get back, I’ll rivet the stiffeners into the left tank, seal the rivet lines, and get ready to start putting ribs in place. They’ll be tanks soon enough.