Missing Sprues: I’m a newbie to lost wax casting. My biggest problem is “missing sprues”. As shown in the photo, one sprue was lost on this brass casting. I have had similar problems on several occasions, resulting in incomplete castings. This item was cast using vacuum assist. It was cast in a 2 ½ x 3 flask. I used Kerr Satin Cast for the investment material. The flask temperature was 1100 degrees F and the pouring temperature was 2000 degrees F. Other castings came out OK. Help will be appreciated. Thanks.