RE: Nuance
I use epoxy. And yes, I glue the edges also. I install the motor/ firewall combo the way i explained a few posts back (before gluing it in) then I make a light pencil mark around one side of the firewall. Usually the back side. Then I use blue tape and tape about 1/4" away from it on the back side, and about a half inch in front of that. Then mix up my epoxy, wet the firewall and the fuse between the tape. Then I add either chopped fiberglass or carbon depending on the firewall material i am using. Install the firewall as i explained and then wipe it clean with my finger to make a nice fillet. Remove the tape after it sets up a little and you are good to go. Probably a little more work than the expensive stuff, but its how I do it and have never had an issue.
Chris