Chris, WalMart usually has JB Weld.
I clean the carbons shafts (inside) with isopropyl alcohol (don't use just any 'rubbing alochol') and cotton swabs until the swab comes out totally clean.
It's probably over-kill, but I clean insetrs with a commercial degreaser, rinse them off, then clean them with isopropyl alochol, followed by boiling water (demineralized, available at most supermarkets for use in steam irons). I also use rubber gloves to avoid any accidental contamination with oils from my hands too. I don't have any trouble at all with inserts coming loose!
For steel adaptors to inserts; clean the threads well; as above; and secure them with LocTite. You'll need a bit of heat and pliers to get them back apart.
Ed
ps: I wouldn't use acetone. It desolves the bonding matrix on most carbon shafts.