Why should I use Replicator instead of alginate for making a mold of the human form?
There are several topics to consider when deciding to use Replicator silicone rubber is used instead of alginate:
1. Mold Life - Alginate is suitable for making molds intended for short-term use, typically 1 – 2 castings. Replicator on the other hand is frequently used because it is a “library life” mold making material. Molds made of Replicator silicone rubber can literally last for years and yield dozens of castings out of the same mold.
2. Casting Medium - Alginate has limitations for what can be cast into the mold due to the fact that it is a water-based material. For the most part, only gypsum-based materials or very fast-setting polyurethane resins may be used successfully in an alginate mold. Replicator silicone rubber does not contain any moisture and therefore can accept many different types of casting media, many of which heat up during the cure process.
3. Tear Strength - Alginates have low tear strength, which limits how far they can be stretched before ripping apart. Replicator silicone rubber can stretch 6 times its original shape before tearing.
4. Weight – Many old makers prefer Replicator over alginate for the fact that they do not have to put as much material on a surface to obtain an accurate, highly detailed impression as they do with alginate. Packing alginate onto a surface adds more weight, which in itself tends to distort the model surface underneath the mold material. Using Replicator silicone rubber allows the mold maker to use much less weight on the model, which will yield a more accurate impression.