Firewall Flange to Boot Cowl Sealing

[Glenn Patterson]

We used the 3M Firestop Sealant FD 150+ From Acklands to seal up the gaps between the firewall & boot cowl. Home Depot has a similar product. We put the sealant in a glue syringe and injected it into the flutes and gaps to seal it anywhere there was a visible void. It cleans up with water, no odor and it went in nice. It is a material that expands in the presence of fire to seal tighter to prevent fire seeping through. Dentists give the syringes out when they extract a tooth so if you cant find them ask your local dentist. I have a bunch of the glue syringes from Lee Valley and they come in handy once in a while. My first experience with the intumescent caulking and intumescent bricks was to seal around aluminum cable trays penetrating through electrical equipment rooms to contain fires. It expands and seals tighter in the presence of fire to keep equipment safe. Our airplane was all ready painted so I recommend installing after it is painted and this was done prior to the final inspection.