Foam Hole-Formers are a low cost hole-forming option that are ideal for single use and limited run productions.

Most orders can be produced and shipped on the same or next day – great for time-sensitive projects.

We can make ANY size, shape, and structure. We can also ship full sheets directly to you.

Mounting magnets are available.


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

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

Foam Mandrels – ANY size, structure, and gasket type!

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

89″ dia. hole for 9″ wall x 96″ I.D. manhole – created by a Blackthorn Foam Hole-Former

92″ OFFSET CORNER Foam Hole-Former for flat wall (on pallet ready to ship)

Challenge: Customer needed a single-use mold for a column base

Solution: a mold made of multi-layered foam!