I am trying to cast this little pendant in 9ct. yellow yellow gold using a delft casting system Click image for larger version.  Name: Model.jpg  Views: 21  Size: 8.8 KB  ID: 12896 however when poured it comes out like this Click image for larger version.  Name: esult.jpg  Views: 23  Size: 5.9 KB  ID: 12897, I think I have plenty of space to let the air out and the same model has worked in silver and pewter, I think I'm getting enough heat out of my oxyacetalene torch but im very new to this so any tips appreciated!

TIA
The Bodger