Worming

WormingWorming presents as excessive metal with a worm-like appearance that normally occurs in corners. This defect indicates metal penetrating weak areas, located on the edges of the shell.

The causes of this defect are evident in the shell portion of the process. To cure these causes, R&R recommends taking the following actions.

 


Area

Cause

Cure

Wax

 

 

Shell

  1. Poor draining due to high viscosity. Slurries need to be applied in an even, uniform coat. When the slurry viscosity is too high or the tree is not drained properly, heavy layers of slurry are left behind.
  2. Poor draining practice. Slurries need to be applied in an even, uniform coat. If slurry viscosity is in range, the draining technique may be leaving heavy layers of slurry behind.
  3. Gelling primary slurry.
  1. Verify that the slurry viscosity is within the recommended operating targets. If not, adjust accordingly.
  2. Observe draining technique. If heavy layers of slurry are being left behind in defect-prone areas, draining must be adjusted so that slurry does not build up prior to stucco application.
  3. Check binder stability and implement a proper slurry control program including a gelation test.

Metal

 

 

Other

 

 

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