Sharpie makes a silver metallic paint pen in 3 or 4 different sizes. I use a Sharpie poster-paint metallic silver extra fine point to do exactly what you are talking about. put the rod together, put the dots on with the pen (shake it very very well, hold it perpendicular to the place where you want the dot and a light touch will do just fine), then apply a light coat of hard as nails over the top of it and you are good to go. If you are just building a rod, apply it directly to the blank if you like and epoxy over the top of it. Allow the silver 20 to 30 minutes to completely dry first.