I only use brushes on the first coat (Flexcoat Lite) and only use enough to coat the thread. When I'm done I can still see the texture of the thread wraps.

For the 2nd coat I use Steel Spatulas. I bought a set off EBAY on the suggestion of another board (rodbuilding.org) and will never go back.

I very seldom get bubbles now, and the few I do get come right out with a bubble buster (alcohol torch).