I bought two single use tank sealant carriages from Aircraft Spruce to make it easier to deploy. I took my time and prepped as much as I could but that black tar gets everywhere. This specific section makes doing the Quickbuild almost worth it alone. That said, pretty happy with how it came out. First thing I did was cleco it all together and make sure I knew what was going where. Then I taped all the edges (both sides) wherever there would be tank sealant going in between two flanges. Turns out you don't really have to hurry. The sessions took me several hours to finish and the tank sealant in the gun continued to be useable all the way to the end. So my biggest tip is to take your time. I felt like there was a clock ticking and so I kept trying to get everything done before the sealant cured. The back riveting session was surprisingly hard. Given the additional soft material in between the flanges and the odd angles of the e tunnels, I ended up setting a bunch of rivets high that needed to be drilled. I opted to complete them all first and get to the center muffler shroud and install the billet (before the tank sealant became unusable) and then went back the next day to remove the high rivets and replace them with new one. Even with the three pieces connected, back riveting was not a big problem. The only problem I found was that when you drill out a rivet with tank sealant around, every chip you make ends up in the sealant. I opted to wipe the chips off with a rag and acetone and then re-taped and re-applied a billet to all the seams. Probably labor intensive but it was a good seal. After I completed the attachment of the firewall to the bottom skin assembly, and clean up any excess tank sealant, I began to rivet the center of the bottom skins to the tunnel. This was another time to modify the instructions according to the OP-62 KAI for the new engine. For the IO-390-exp119 there will be a cowl-flap in the belly that will attach with #8 screws to the skins. So instead of riveting the entire center section, I installed 5 nut plates in each. This was a bit of labor and again I had to prevent metal chips from going into my tank sealant. This time I placed tape over the seam so that it blocked Ben and then vacuumed them up before removing the tape. Tank sealant is a big pain to work with, even several hours after you finished setting it. I have to now install these nut plates and then rivet the rest of the assembly but I am %90 of the way finished with this section. By the way, a couple tips for tank sealant. 1) You have plenty of time. Move slowly and don't rush. 2) Have plenty of acetone and a rag (not just paper towels) you can use to clean. Rags soaked in acetone work very well, just avoid contacting the billets or seams you mean to keep. 3) Have popsicle sticks and q-tips ready to detail the cleanup. Works wonders. 4) When you finish, you can re-tape and apply a nice straight line if you notice that your seam doesn't have a clean line or a spot that doesn't have any sealant sticking out. 5) clean off the rivet heads after you squeeze or buck then before you measure them with the gauge. The tank sealant will give you a false sense of the diameter of the shop head. Oh, but my biggest tip of all: Pay for the Qucik build. Let Van's do the table sealant ☺�Only partially kidding).