For years I used a brush to apply finishes. I found that if the material was thin enough I could get a decent job of it , if I used a good brush - sable. I could never get a thicker product like epoxy to work.
Now I apply everything from thinned down lacquer CP to high build epoxies , using a dubbing needle. I can control how much goes on and I can work it into the threads. With good lighting I can see how thick it all is ( and I apply thin coats) and I can push it around if I need to. It is slower than a brush but I figure I already have how much time into this rod?
Besides I enjoy this stuff.
AgMD