Vulcanized vs. RTV
Spike, there is one RTV available that has high tear strength and
perfect hardness. It is clear to boot. It is called Akron Silicone
RTV and is made by Zero-D Products, Inc.
As far as I know, it is the only truly high tear strength silicone
out there today. All of their products are great.
Website is www.zerodproducts.com