Section 27 Firewall was completed today. 28 hours used. This is section 27 Firewall. All parts. The aluminium parts. To back rivet the holes in the middle of the firewall, my back rivet plate was to large. So I used the tungsten bucking bar instead with some tape to hold it in place. That worked very well. I was a bit worried of how messy the tank sealing would become, and decided to use tape below the top firewall skin. No problem then. I used the 2Oz Chemseal B2 Tank Sealant Cs3204 from Aircraft Spruce. I think the consistency was better than the one I purchased from Vans Aircraft for the elevator. One have to be creative to set all rivets alone. All done. The remaining clecoes sits in the holes where the battery box til sit.