Limited Use Foam Hole-Formers


  • Great for Limited-Run Productions
  • Low-Cost Hole-Former / Knockout Alternative
  • Available in Flat Wall, Clyindrical Wall, Full Sheets
  • Mounting Magnets Available


18″ Dia. Parallel Foam Hole
for 6″ Wall x 60″ I.D.
(Functional for VORTEX manholes)


64″ Dia. Foam Hole
for 9″ Wall x 96″ I.D.
(Custom cut for Split-Barrel Application)


2″ PVC and 4″ PVC Septi-Seal Gaskets on “Ready-To-Pour” Foam Mandrels


89″ dia. hole in a 96″ I.D. manhole base

Created with a Foam Hole-Former made by Blackthorn!


Challenge: Needed a One-Time Use Mold for the base of a column


Solution: Mold made of Multi-layered Foam