brass pouring

The pouring practice used for copper base casting al­loys does not vary much from that used for other metals:
Improper pouring may produce excess oxidation and if the oxides an: washed into the castings, they may show up during machining operations. When casting aluminum bronzes it is most important to pour in a non-turbu1ent fashion because the oxides fanned are tenacious and strong and can cause irreparable damage in the casting.
Alloys with high zinc content have a pronounced tendency to form oxides during pouring. It is important that the sprue be kept full and that the stream of metal from the crucible or ladle be uninterrupted while the mold is being filled. Splashing, dumping, or other such practices must be avoided.