I do a lot of minor venting in molds. I have a set of jeweler's files, several of which have very thin sharp edges that are perfect for cutting in vents. I'd agree with Bob that if a mold has major issues it should go back to the make to get them corrected, but most often a little touch up here or there will resolve the issues. Sometimes just changing the plastic from soft to medium, or vice-versa, will get the job done. Rick makes quality products and only one of his molds that I own has needed some real minute dinging with a file. I have one from BassTackle that deals me fits when the mold gets warmed up and only then. I have added and increased venting on that sucker several different times but now just deal with it. I change from medium to soft plastic when the mold gets into it's mood.