My powdercoater guy placed bungs into all holes to keep the blasting media out of it. He has some sort of pliable rubbery stuff that presses into the holes then expands to keep the media out. None was in the intake when he was finished and even then after several minutes and times being blown out,did anything come out. He is really particular in his ways. I realize not everyone is like him so you need to keep an eye on your powdercoater guy.