ilovefire wrote:well i am using 13mm ID 1mm walled aluminum so that should but enough for a few x hybrid.
That looks about right, area goes down exponentially with diameter so you should be ok with good quality epoxy.
Again, looking at the way the plug popped out, it's clear that what happened was not that the epoxy sheared - indeed the parts that were moulded into the roughened bits were still apparent on the sides of the plug - but the chamber expanded outwards and pulled away.
The only time my ears were really ringing was when in my adolescence I rather stupidly put some magic powder in a steel 55 gallon drum with an open top, I was tone deaf for a good few minutes
ah, the innocence of youth...
but im not really one to talk, i have had my ears ringing on more then one occasion and a complete momentary loss hearing playing with shall i say, magic powder 
