RE: Can PU replaces DOPE?
Titebond is aliphatic resin.. yellow wood glue. It is fuel proof when cured. I use it, watered down, instead of epoxy to seal the inside of the fuse and any areas around the engine where fuel might attack raw wood. It sure weighs a lot less than epoxy when it is dry. If you have ever put a horizontal stab in a slot in the fuse, it works great. It cleans up with water.
BTW, CA is not fuel proof.
JR