ORIGINAL: rgoldy
For hinges-gorilla glue as it expands to fill the hole. DO NOT use gorilla on any surface that vibrates (i.e. firewall) as it ain't the strongest glue on earth in those applications. Also, for your hinges make a aluminum foil cup and melt some vaseline in it with your heat gun. Bend the hinges and dip the hinge portion in it and allow to cool. This protects the hinge area from glue (whatever you choose to use).
I disagree. I have used poly glue exclusively on firewalls and LG mounts for years. Maybe you got a bad batch of glue? I find epoxy is more likely to crack and break over time than poly glue.