Block-Outs & Hole Formers
Polyurethane rubbers are often used to cast reuseable shapes which are placed in rigid molds to makes holes or recesses in concrete panels for a variety of purposes. If a pipe needs to pass through a concrete wall, a hole formed by a rubber cylinder inserted into the main form allows it to be moved anywhere in the form and reused over and over since the rubber is highly abrasion-resistant yet flexible enough to be removed without damage to itself or the cast panel. Higher hardness polyurethane rubbers such as the Poly 75 & 81 Series are the systems of choice.
