PlatSil® 73-45 Silicone Rubber

platsil-73-45PlatSil® 73-45 is a 1A:10B mix, mid-range hardness (A45), platinum silicone mold rubber. Molds made with this rubber have long mold life, high chemical resistance and no shrinkage on cure. PlatSil 73-45 molds have great release properties and, in most cases, do not require the use of release agents when casting.

Cured PlatSil 73-45 rubber has the highest tensile strength, tear strength, and elongation (%) properties in the PlatSil 73-Series. It also has the longest pour time (60 min).

This rubber is great for making molds for all types of resin casting (polyurethane, polyester, epoxy) and foam casting. Often used for prototyping, model making, high density polyurethane foam casting, and much more. A very popular rubber for casting foam architectural millwork, pots, plaques and other foam décor items.

Pour PlatSil 73-45 as supplied or thicken for brush-on molds using PlatThix liquid thickener.


Mix Ratio Shore Hardness Pour Time Cured Color Mixed Viscosity Specific Volume Demold Time
1A:10B A45 60 min. Green 35,000 cP 21.3 in³/lb 16 hr.
Accessories: PlatThix Liquid ThickenerPlatSil® 71/73 Part R RetarderSilicone Fluid 50csPlatSil® 71/73 Part X Accelerator


Product Literature: Technical Bulletin | Safety Data Sheets | Physical Properties Bulletin | Sealer & Release Agent Selection Guide

Video Tutorials: For 73-Series video tutorials, visit the 73-Series page or the Polytek YouTube Channel.


Select a Kit: