The sides of the skin need to be really tight, so I apply a thick line of sealant. On the ribs I only apply sealant around the rivet holes, except for the most inner and outer rib. Those again need enough to get it leak free.

The top and bottom rivet hole of the five ribs are pop-riveted first. the other five holes of those ribs are riveted with the tank attach angles.

The inner and outer rib can be riveted with “normal” 470 rivets and the squeezer. Except for the tank attach angle, because there is not enough room for the squeezer. We use the rivet gun and bucking bar instead.

I screwed up by using rivets that were too long and even with the squeezer, you will still mess them up. They just bend every which way. So I drilled them out and reset those rivets with the correct size.

I hope the tank doesn’t leak, because working with sealant creates a mess on the tools. A good cleanup with acetone is required.

As a preparation for the next time I discussed the position of the pitot-tube. The original (Van’s) pitot-tube is just an Aluminum tube through the wing skin behind the aileron bell-crank of the left wing. My assumption (see where I went wrong) was that the Dynon pitot-tube with angle of attack, was also placed there.

I figured out that that would never fit, so I was looking for alternate positions. Since I’m not going to build the stall warning (with the AoA), I figured I could use that bay just on the other side of the main spar. It would also give more space for the tie down. However you do need to drill two small holes through the main spar, which I don’t like.
While “rubber ducking” these options to my dad, I actually read the installation manual (instead of assuming what they mean) and found out that the manual also used another location. Not on the leading edge, but in the bay beside the one with the bell-crank. This one is still reachable through the lightning-hole in the ribs.
Hmm, note to self, RTFM (again)!

Time: 5 Hours, Rivets: 241/5

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First step is mixing the tank sealant, we are getting quite experienced in it and combined with our kit dispenser “trick” it’s really easy.
Before starting on the right tank leaks, I prepare the Left Tank Baffle by sealing the fuel sender. The sender is in the second bay, because the first bay is occupied with the Flop Tube.

We added a thick line of tank sealant ad the outboard rib and we removed the gasket completely and replaced it with tank sealant. It will make it harder to reopen the flange, but if you need that, you are already in deep shit.

This time we didn’t make enough tank sealant, so half-way we had to mix a second batch.

While my dad removes the cleco’s and inserts the rivets, I use the squeezer to set the rivets. The tank attach angles on top of the baffle are pop riveted, since it’s impossible to reach them.

Cleaning up the tools with acetone, works like a charm.

Now I have to wait until the tank sealant in dry and then we can re-test the right tank with the water test. Also we need to test the left tank with the “air” test. I’m a bit tensed as I sincerely hope the tenk is leak-free. If not we need to fix it and that is probably not easy.

Time: 5 Hours, Rivets: 188/0 (2018-10-28)

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After mixing the two components of the Tank Sealant, we installed the inner ribs to the bottom of the leading edge skin. Just as the previous tank, although the manual states differently, I think this method produces a better result.

The Cleco’s sometimes don’t fit, because the drill holes don’t line up. A small hit with a rubber hammer works great.

Although the leading edge is not that “deep” that you could rivet it on yourself, I really like to do it with two persons. In this case my dad operates the rivet-gun, while I handle the bucking-bar.

For the outboard and inboard ribs we can use the squeezer. Also the rivets themselves are less likely to leak, since the fuel is on the other side of the rib.

Here is the final result of the inboard rib, with the fuel pickup line and fuel sender installed. A few days of letting the sealant dry and then we can do the water leak test.

Time: 4 Hours, Rivets: 21/1 (2018-10-13)

Time: 5 Hours, Rivets: 270/0 (2018-10-14)

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Now we can use the kit dispenser to put tank sealant on the flanges of the ribs. I decided to deviate from the plans, as I didn’t like to “squeeze” the ribs in the skin while it was sitting in the cradle. In my mind the dimples would smear the tank sealant from its place increasing the chances of leakage.

So I decided to add tank sealant on both sides of the rib (bottom and top) and instead of “squeezing” it in, just cleco it to the bottom of the skin.
You can see this is the last inner rib, the others are already clecoed in. Meanwhile the top is still free.

After clecoing all ribs, we “squeezed” the tank into the cradle, bending the skin instead of “squeezing” the rib. It went really well and I will use the same technique on the Right Wing Tank. After all the ribs are in and the tank is in the cradle we start riveting.

In the nose part of the Tank it’s not that easy to set the rivets. Here working with two persons is not a luxury.
The inner and outer most ribs still need to be done with “squeezing” the rib, because of the excess of tank sealant involved I didn’t worry.

For those two ribs we can use the pneumatic squeezer (top word in this post).

I could have prepared the inboard rib better, now we needed to seal and rivet the attach angle, so it took us 6 hours of working on the tank.

Because of the bulkheads, I used the other yoke.

Here’s the result. I tested the tank and it leaked on the gasket of the big hole. Without thinking too long, I threw out the gasket and used tank sealant to seal that part.
Maybe I should have been more patient and wait if the gasket would need some time emerged in water to get set.

My biggest frustration of this tank is that the hole didn’t have to be there at all. If you use a flop tube (as I do in the left wind) that hole is not necessary. So it took me 30 minutes to create the hole and than another hour to seal it tight again.

Well you could argue that if something goes wrong with the bulkheads later you still have access. However that would be awkward to work through that hole as it isn’t that big at all.

Time: 6 Hours, Rivets: 259/1 (2018-09-26)

Time: 4 Hours, Rivets: 1/0 (2018-09-30)

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First step is cleaning up all the parts and degreasing them.

Start the clock, we are mixing the tank sealant components and we now have about two hours to finish the work (turns out after three hours it still looks ok to use. I’ve bought a dozen empty kit containers which you can use to fill yourself. By following the channel of Jason Ellis, I found he liked the kit dispenser ProSeal. Since I already bought the inexpensive quart tank sealant, I wanted to experiment with empty kit containers.
This worked out fantastically, it’s really a great way to seal the tanks.

There is a trick however in putting the plunger in the container. You can’t get the air on top of the sealant out. Our first attempt was to squeeze the dispenser hard enough that the air would escape at the side of the plunger. That didn’t work. Finally I used a thin piece of scrap aluminum which I stick into the container together with the plunger and it created enough space for the air to escape.

Here’s my action list of sealing and riveting the tanks:
1) put a drops of tank sealant in skin dimple

2) lay a line of sealant on both sides of the rivets

3) put a drops of tank sealant in the stiffener dimple
4) back rivet

With the excess of tank sealant we also sealed and riveted the water/fuel drain, that is at the lowest point of the tank and allows for draining the tank with condensed water.

There was even enough sealant left for the fuel caps.

I feel confident next time to insert the ribs and seal the tanks. Working with the sealant is less hassle than anticipated, although you get sticky fingers. The empty kit container and dispenser is really helpful.

Time: 5 Hours, Rivets: 208/0

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