Assemble 10/22/22 – 1.2h 10/23/22 – 1.6h 10/25/22 – 1.6h 10/26/22 – 1.4h 10/27/22 – 1.7h 10/30/22 – 1.6h 11/2/22 – 1.4h 11/3/22 – 1.0h 11/6/22 – 3.6h 11/7/22 – 1.9h 11/8/22 – 1.8h 11/9/22 – 1.3h 11/10/22 – 1.5h 11/15/22 – 1.1h 11/16/22 – 2.6h 11/19/22 – 1.9h 11/20/22 – 1.7h 11/24/22 – 1.6h 11/25/22 – 1.8h 11/27/22 – 1.6h 11/28/22 – 1.4h 11/30/22 – 1.6h 12/2/22 – 0.9h 12/3/22 – 2.2h 12/4/22 – 3.7h Mixing sealant straight out of the cans is messy and time consuming. The sealant sticks to everything, and measuring out just the right amount on the scale takes a lot of dipping and scraping with the mixing sticks. I decided to put the sealant and catalyst into separate syringes to simply squirt the amount of each I needed onto the mixing plate on the scale. This method is much better and cleaner than scooping sealant out of the can with a stick. The syringes are stored in air-tight zip-loc bags, which should be just as good as storing sealant in the can. I started with back-riveting the fuel tank stiffeners into place. Loading the rivets into the skin before any sealant is applied is nice since the dimples and rivets are totally clean at this point. After getting all of the rivets loaded and taped in place, I mixed 10g of sealant and 1g of catalyst. For reference, this was just enough sealant for me to install 5 stiffeners (1 row) including complete fillets on 2 of the stiffeners. It took roughly an hour from the time I started mixing to starting clean-up at the end. 10g + 1g turns out to be a good amount for me to work. I used the Vans tank assembly video as my technique template for the sealant. I first spread a medium coat of sealant on the bottom of a stiffener and then used a popsicle stick to bevel the sealant over the rivet holes and remove the excess. When I pressed the stiffener into place over the rivets, I noted a small amount of squeeze out around the entire part, which indicated I applied the correct amount of sealant. Back-riveting is standard, but it is easy for the rivet gun to slide a bit due to the sealant. I was happy to see at the end of the process that a very small amount of sealant had worked its way through the rivet hole to the manufactured head of the rivet. Each dark grey circle on the back-rivet tape indicated to me that there shouldn't be any leaks through these rivets! I'll go back later to encapsulate the rivets and finish the fillets to make sure there are no leaks. The pneumatic squeezer worked well to rivet the quick drain flanges in place. I followed the Vans tank assembly video by applying and troweling sealant on the back of the flange, aligning it to the holes with a couple of clecos, and scooping excess sealant out of the holes with a paper strip. I was surprised to find how difficult it was to insert rivets into holes with sealant in them. The rivets fit fine in the dry holes, but required a lot of effort to insert them for final assembly with the sealant. I used my pick to both align the holes and remove some additional sealant, which allowed me (with a little force) to insert the rivets. The ribs will be exceptionally difficult if I run into the same issue with them. Van's tank assembly video uses a pneumatic rivet squeezer with a small yoke to rivet the fuel filler flange in place. I planned to do the same on my fuel filler flanges, but my 1” yoke is too big to get adequate access to the rivets due to the funnel shape of the flange. The next option is to buck the rivets, but I was not comfortable with that approach. The tank skins do not have any sub-structure in place at this point of the build, and I was concerned that would lead to damage in the riveting process. I researched some other projects where the flanges were back-riveted with good results, and I decided to try that method. There is some curvature to the skin from the leading edge to the aft edge, which complicates back riveting a bit. I decided to start with the aft-most hole (with the vent clip) and work my way forward. That allowed the skin to follow its natural curve from the aft to forward edge while the rivets being set were held flat on the back-rivet plate. I was happy with the riveting results, and hopefully there won't be any leaks! Ribs, starting with the inboard forward ribs are up next in the tank assembly. The inboard and outboard ribs are unique since sealant is only needed on the inside edge of the rib and not the entire flange surface. The result is a slightly cleaner installation since there isn't any significant squeeze out on the outside edge of the rib or rivets. The forward inboard rib is a bit difficult to align with the leading edge of the skin, but some “gentle” persuasion with the pick got it into place. I used the pneumatic squeezer for the rivets on this rib, which worked just fine. After riveting the rib in place, I formed a very generous fillet of sealant along the inside edge, and used my remaining sealant from this batch to coat the outside flange where the rib is notched to form the leading edge curve. I stretched the sealant I had as far as I could, but the outside treatment may be a little thin requiring some additional sealant later. The interior ribs are installed with sealant along the entire flange area. Each rib required 20g +2g of sealant, which was enough to coat the flanges with acceptable squeeze out and create fillets on both sides of the rib flanges. Van's tank assembly video covers the installation of the interior ribs really well. One difference from the video for me was using the squeezer on the aft-most rivets. I have access to a 4” squeezer yoke, but the aft rib flange prevents clean access to the rivet. Bucking all of the rivets, including the aft rivets, worked well. Prior to inserting each rivet, I used a pick to align the hole. That had the additional benefit of removing excess sealant from the hole. I also inserted a cleco adjacent to each rivet I set to help hold things tight as I worked from the leading edge to the aft edge of the tanks. One change I made after the first couple of ribs was to set the tank on end after setting all the rivets for the ribs to work the fillets. I inspected each of the fillets and encapsulated the rivets that were already set before installing the top J-channel tank stiffener. Most of the fillets looked good, but there were a couple of thin spots that I touched up with some additional sealant. The Van's tank assembly video recommends using an aluminum tube to encapsulate the rivet shop heads, so I bought a .058 x 5/16 x 9" T6 aluminum tube from Van's to make a rivet encapsulation tool. I cut a 3” piece of tubing for the tool, and then finished the tool by deburring both ends of the tube and flaring the end used to encapsulate the rivets. I set the tanks on their sides on the work bench and used a gravity assist to encapsulate the rivets on the bottom side. I let the tanks sit on their sides overnight before flipping them over to encapsulate the rivets on the other side. Fingers (and toes) crossed that there won't be any leaks! Installation of the J-Channels means the light at the end of the tunnel for this step is a little brighter. The J-Channels for the fuel tanks are just like the J-Channels for the outboard leading edges, with the notable exception of tank sealant. The build instructions specify that the sealant should be applied to the J-Channel rather than the skin, and skin contact with the sealant should be minimized while sliding the J-Channel into position. There will be some contact when the J-Channel is inserted since clearance between the J-Channel and the skin is very tight. The result is a lot of drag on the J-Channel as it gets further down the line of ribs toward its final position. Working and inspecting the sealant fillets on the back side of the J-Channel is also a little tricky, and requires a lighted, flexible mirror to ensure the fillets are done correctly. The final piece of this step is installation of the tank attach bracket subassembly. Access for the tank attach bracket is really good – both for sealant and riveting. I applied sealant to the bracket flanges similar to the ribs, and I applied sealant to the interior side of the top flange on the forward inboard rib to form a large fillet on the interior junction between the rib and bracket. Actually forming the fillets on the “blind side” of the bracket is similar to working the J-Channel fillets, and requires a small lighted mirror to see how the fillets are formed. [Large Syringes, Kitchen Scale, Mixing Sticks, Large Back-Rivet Plate, 3x Rivet Gun, Back-Rivet Set, Swivel Flush Set, Tungsten Bucking Bar, Rivet Gauge, Pneumatic Squeezer, 3” Yoke, Flat Squeezer Set, Flexible Mirror with Light]