I think gorilla glue has some epoxy that I might try out, I love their products. Now to find an 8" cap or **** it up and go with a 6" again //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif
Good luck.. I'm not fond of Gorilla Glue.. Goop has always been stronger IMO... I got to the point when 'gluing stuff' I just used Goop for everything because its so strong..
i have thick 7" caps with a wide glue edge and they are poly.
use e6000 i do on all my builds and have never had 1 come off. make sure to sand the back of the dustcap with 50-100grit where it contacts the cone, that is a must...
Do not use epoxy on a dustcap unless its rubberized. I agree goop is your best bet (its what I use). It is tough yet flexible which is what you need for a dustcap.