VFI-2131 30 A TDI Molding Rubber

Thickness Requirements

Pour the material into a single spot at the lowest point of the mold until the desired thickness is met. VFI recommends pouring at a minimum of ¾ of an inch thick. If pouring less than ¾ of an inch thick, we recommend using a higher shore A hardness scale rubber.

Mold Preparation

All surfaces should be clean and free of oils, dirt, or debris. Use a non-hardening sulfur-free clay on molds to prevent unwanted adhesion and improper cure. Porous surfaces such as natural stone, wood, or concrete must be properly sealed for ease of demolding. VFI recommends using a mixture of 80% mineral spirits to 20% petroleum jelly by weight as a sealer. Apply several layers of the mixture with a small chip brush, waiting for each layer to dry before adding another. After sealing, spray a light misting of a release agent over the entire molding surface to prevent unwanted adhesion. We recommend using Chem-Trend MR-515 Aerosol or a similar release agent.

Non-porous surfaces only require the use of a release agent. Using a release agent helps to protect and extend the life of the mold. Avoid spraying too much release, as this can produce a shiny/glossy surface on the rubber that will transfer to future castings. The material is compatible with most molds as long as it is used with a proper release agent.

Mixing

The material should be at least 65°F before use for proper mixing and application. Mixing times may vary depending on volume and mixing method. Vacuum degassing can further reduce air entrapment but is not required.

Thoroughly mix the POLY “B” component before mixing with the ISO “A” component. Usually this takes a minimum of 3 minutes per “B” container with proper mixing equipment. Once the “B” component is thoroughly mixed, properly pour 1 part of “A” component into 1 part of “B” component by volume, 100 parts “A” component to 97.3 parts “B” component by weight. Thoroughly mix for at least 30 seconds while ensuring that the mix is uniform and homogeneous. Transfer into a new, clean container and mix again before use. Be sure to scrape the sides and bottom of the container for uniformity.

Post-Cure

Allow the rubber to sit at room temperature for a minimum of 16 hours before demolding. The rubber will develop full physical properties after 7 days at room temperature. It is required that the rubber sits for 3 days at room temperature before use. If the cured rubber is used for casting, a release agent should be applied before each use. Use a release agent from a reputable release company, such as Chem-Trend, Stoner Molding Solutions, or Cresset Chemical Co. Do not use a solvent-containing release, as it can distort (shrink or expand) the mold.

Storage/Shelf Life

Store between 60°F – 90°F in a clean, dry building. The shelf life of unopened containers is 12 months after the date of manufacture. Once open, use it immediately. If you plan to store open containers after use, both sides must be nitrogen purged to try to extend the material’s shelf life.

Precautions

This product contains isocyanate, which can irritate the skin and is toxic if inhaled as particulate matter. Avoid prolonged breathing of vapors and repeated skin contact. It is not UV color stable and has no long-term UV testing. Urethanes are moisture sensitive and may bubble if exposed to too much moisture. VFI-2131 cannot be tinted. Use only with adequate ventilation. Do not thin or add foreign material to the product. See the Safety Data Sheet for complete safety instructions.