Poly-Fast 72 Part C Softener
Poly 72 Series Part C is a liquid additive that can be added to Polyfast 72-40 liquid rubber to reduce the Shore A hardness.
Can be added to create rubbers as soft as a Shore A~6. Part C should be weighed and thoroughly mixed with 72-40 Part B before adding A. Each 20 parts of C added to 100 parts total A+B lowers the hardness by about 10-15 Shore A points.