Fiberglass Cowl Problem

Hello All: I have 10-32 screws with 8s size Tennerman Washers as attach
fittings. The cowling holes have worn slowly but surely and now I know it is
time to fix this vibration problem. I like the size of the 8s but I suspect I
really should use 10s. They are unpainted and not bonded to the cowling. My
questions are 1) I think the solution would be to epoxy the Tennermans (larger
size ) to the cowling now that the hole is getting too big. 2) Should I flox
them in place from inside for a more secure bond? I haven't been bothered
before now with the washers "free floating" for lack of a better word. I've
liked the chrome look but maybe they should have been bonded when I had the
cowl Emron painted 200 hrs ago. What seems to be the conventional fix for this
problem as it will only get worse if I don't do it right soon? Thanks

Larry