compression set of tin catalyzed silicone better than platinum?
Tin catalyzed silicone lasts for a couple of years and platinum catalyzed lasts for 10 years, after which they lose their elasticity, becoming brittle and splitting. So while they may have equal properties for the first year, After a while the Platinum silicone will perform better. Using less catalyst for longer cure times also increases durability, and vacuum treating the silicone prior to casting and heat treatng it afterwards increases it's compression set performance.