1) Coaches 2) Coaches beforehand 3) Gets ready to simper 4) Good meats 5) Indivisible numbers 6) Instructs beforehand 7) Makes ready 8) Prepares for firing 9) Prepares for painting 10) Prepares the pump 11) Prepares to paint 12) Rate and rib 13) Starts a pump 14) Two and three, for two 15) Undercoats a surface Found on https://www.crosswordclues.com/clue/primes