Frequently Asked Questions

We have questions and answers to help you decode the terminology and the fundamentals of mouldmaking and casting.

  1. What are the major differences between tin-cure (condensation cure) and platinum-cure (addition cure) silicone mould making rubbers? The chemical distinction between tin-cure (condensation cure) and platinum-cure (addition cure) silicone mould making rubbers primarily lies in the metal used for catalysis or curing of the base rubber. Tin is utilised to catalyse or cure tin silicone, while platinum is employed for curing ...
  2. Do I have to vacuum de-gas the silicone rubber? Is vacuuming the rubber that important? Many mixed silicone rubbers (A+B) tend to be viscous and possess a high viscosity. Silicones with a viscosity exceeding 15,000 centipoise should be subjected to vacuuming to prevent the entrapment of air and the formation of bubbles in the final mould. If you blend and pour silicone rubber ...
  3. How do I release silicone from silicone? Silicone-to-silicone applications, such as creating two-part moulds or casting silicone into silicone, are feasible but necessitate the use of a release agent. This release agent must not contain a substantial quantity of silicone oil. Here are some release options: Mann Ease Release™ 200 is ...
  4. How much mold rubber do I need? Estimating the quantity of material required for a project can be a challenging task. Insufficient material or excess leftover can be not only frustrating but also costly. Several factors need to be considered, including the complexity of the model (varying dimensions, configuration, undercuts, ...
  5. Why are there bubbles on the surface of my rubber mold? Bubbles that appear on the working surface of a cured rubber mould can compromise the fine details and render the mould unusable. Bubbles can originate from various sources, and several variables (most of which can be controlled) influence the size and quantity of bubbles produced. Q: I ...
  6. Do you have a rubber that is food safe for casting chocolate and other food items? Certain Smooth-On platinum silicones have received certification for safe food contact. Smooth-Sil® 940, Smooth-Sil® 950, Smooth-Sil® 960, SORTA-Clear® 40, SORTA-Clear® 37, SORTA-Clear® 18, and the Equinox® Series are suitable for creating baking moulds and trays, ice trays, casting ...
  7. What is "cure inhibition"? Cure inhibition occurs when a surface contaminant prevents a material from curing as expected. Experiencing Inhibition When Making a Mold When making a mould, cure inhibition occurs when contaminants on a model's surface prevent the liquid mould rubber from curing correctly. While the cured ...