Cause of choking of casting parts
Is it boiling from the picture? Does it sound like a fire? If not, it's not choking. I feel like choking. The gas doesn't drain out
The reason is not in the coated sand, see coating gas evolution, the best use of zircon powder coating (low gas evolution), there is a mold according to a vent needle, this depends on your way is flat or vertical pouring pouring pouring, if vertical pouring, venting pin on the die, and the big piece how could the plane, pouring water flat, a breath, a taboo ah!
Choke fire is the process of pouring a large number of gases can not be discharged smoothly, boiling in the metal liquid, resulting in a large number of castings in the pores, and even incomplete casting defects
