Zak Jewelry Tools

Castaldo® Rapido® Molding Rubber

Castaldo® Rapido® jewelry molding rubber is a VERY FAST version of our Super High Strength®, Econosil™ and other silicone jewelry molding rubbers that can speed up your work significantly. It makes tough, strong production rubber molds in as little as 15 minutes. Castaldo® Rapido® jewelry molding rubber gets your models into production FAST! Castaldo® Rapido® jewelry molding silicone rubber cures at 93°C / 200°F and makes molds with a rubber shrinkage rate of only 1.4%. Castaldo Rapido is a soft clay or putty-like material that is easy to work with, just like our Castaldo Super High Strength , Econosil and other silicone jewelry molding rubber compounds. Castaldo® Rapido®  produces highly detailed wax injections with an extraordinarily shiny surface that requires less finishing. Waxes are self releasing and need no release spray or messy powder. Molds are easy to pack and cut like butter. Rubber shrinkage is only 1.4%.
Special note about shrinkage rates:
The figures given for this and all other rubber molding compounds are for the rubber mold itself, not the wax pattern it produces or the final casting produced from the wax pattern. The same rubber compound molded around the same metal master model can produce highly variable final casting shrinkage rates depending on the mold maker & caster’s skill, knowledge, precision and attention to detail. Final casting shrinkage is the result of the jewelry manufacturer’s procedures. Strips measure 18" x 2 7/8th" x 1/8th" (45.7 cm x 7.3 cm x 3 mm).  5 lb. strips. Instructions. 
                                                           
Shore A Hardness 38-40
Vulcanizes at: 93 ̊C / 200 ̊F
Rubber shrinkage Very Low 0.1%
Elongation before break 614%
Tensile strength before break

1,289 psi

8.9 n/mm²

Tear Strength before break

104 lb./in.

18.2 n/mm

Uses Fast 15 minute molds. High Strength, General Purpose.
Color Marigold
MSDS Here