Epoxy generates quite a bit of static which can contribute to EMI issues.
Things to try:
- change the carbon brushes in your router
- ground your dust collection setup
- lightly spritz the stock with water before cutting
To really ground everything to earth, use one of these: http://amzn.com/B00MNP1I3I
Clip it to bare metal on the X rail and plug the other end to an outlet.
Another thing you can do is ground the router itself — this should be done w/o defeating the double insulation of the electronics. Best advice is to connect the router body electrically through the dust shoe (I just wrap a bit of foil tape around it) along the hose (either use a conductive hose such as: Dust Collection Hose | Dust Collection | Peachtree Woodworking Supply or run a bare wire from the dust shoe (or start it at the router) and if your vacuum isn’t designed to ground the hose, then connect it to the same ground as the vacuum.
An excellent post discussing this is: