A few people have asked me how I coat boron fibers with glue to secure them to motorsticks/tailbooms/etc. I made a coating tool some years ago that works great for this. It’s made from thin aluminum (about the same as a coke can). I formed it into a bowl shape with pliers, and over a hard surface, punched a sewing pin through it which was reamed out to about .020″ diameter. Using the sewing pin to punch through flares the hole slightly so that the boron fiber slides in more easily.
To use this tool, pour a glob of Duco in and thread your boron fiber through the hole. Wait about 10 seconds before grabbing the protruding end of the boron on the other side. You can now grasp the mostly dried end and pull the fiber all the way, being careful to pull straight down. This is best done while standing so that you can let the freshly coated fiber fall freely to a hanging position between your fingers. Wait for the glue to tack up and then set the fiber aside for use. The glue is reactivated using acetone once the fiber is in held in place on the intended component.