• Number of pieces and spacing.................too close may result in hot spots (shrinkage porosity or fins from cracking due to stresses set up)
  • Separation of light and heavy pieces……...shrinkage porosity in heavy pieces when light pieces finally complete
  • Types of pieces and location on tree……….shrinkage porosity in heavy pieces when light pieces finally complete
  • Joining techniques sharp corners……………..sharp ends or points may break and get trapped in pieces resulting in large holes in piece
  • Angling of pieces……………………………………......assists in smooth metal flow
  • Sprue size……………………………………………….......sprue or main tree rod, button, and feeders weigh at least as much as total of pieces or porosity may result
  • Gate size and connection……………………….....if smaller than section attached to it may result in shrinkage porosity; if more than 20% larger it may result in porosity also
  • Pattern wash…………………………………………........check investment procedures or burnout procedures