Day: March 9, 2024

How to Use Liquid Polyurethane Rubber for Flexible Duplicate Master MoldsHow to Use Liquid Polyurethane Rubber for Flexible Duplicate Master Molds

Liquid polyurethane rubber is a medium to firm curing system that can be poured or brushed on and cures with negligible shrinkage. These versatile rubbers exhibit high tensile strength, impact and abrasion resistance. They are ideal for production casting of concrete, gypsum and wax. They also offer a great blend of economy and performance for making flexible duplicate masters, tools and molds for architectural reproduction and restoration projects, art products, hobby, craft, prop and display applications.

Liquid Polyurethane Rubber: Innovation in Roofing Materials

To use this product, prepare the surface of your model with a separator/wax or other material that will prevent the casting material from sticking to it (this is especially important for porous models). If your models are made of different materials such as natural clay or wood, it is essential that you treat them with an adhesion primer such as Xtend-It. This will help generate the best bond between your materials and the liquid rubber.

It is recommended that you coat porous models with a sealer, such as a shellac or a masonry sealer, before molding to prevent air bubbles forming in the mold. Porous modeling clay, such as Roma Plastilina, must be sealed with a non-sulfur sealing agent to avoid absorbing the urethane rubber. Non-porous models should be coated with a release agent, such as Pol-Ease 2300 Release, or PolyCoat. This will prevent the cured rubber from sticking to your model and make it easier to remove the finished cast. This can be done with a brush, spray or sponge.