After drilling F-840 I deburred and cleaned it. Then I coated the ends with grease to keep the primer from sticking to the place where the end caps would go on and cause a potential problem. That worked well. I did find that the end caps fit REALLY tight. I seemed like the plating on the end caps was rough. I put them in the drillpress and spun them up and ran a little sandpaper on them. This worked great and the slipped right in! After primer dried I took a little solvent and cleaned out the ends of the rod. When I was ready to put them together I shot a coat of primer in each end and placed the rod in and clecoed. I then pulled the rivets and now all the rods are complete!