I put two coats on, one after the other, using just the tip of the tube as an applicator.
When it's set, in about 5 minutes usually, I hit it with my hair dryer to be sure all the solvent is gone, wet sand with 400 grit, and start painting. I don't prime, but start immediately with the airbrush paints.
I carry super/crazy glue in the brush-on bottle on my boat, for on the water repairs.
It is great to help close cuts and hook punctures that won't stop bleeding, too. Just try not to contaminate the glue brush with blood, or the whole bottle will set up and be wasted.