Future Problems

I've been putting it onto a rocket to be used for this year's 4-H fair. I have the nosecone glossy after a single cost with a paper towel, but after a few coats with a paper towel on the payload section it is not glossy, and you can see a ton of sanding lines (800 grit sand paper). I then tried to spray it on with a pump spray bottle in a 50/50 formula with water. This worked somewhat, but ran, and although it filled in, still left little dots. The lines are still visible also. I need help!! What can I do to remove the sanding lines and how can I keep the gloss look of fresh future after it dries?