did you anneal the gasket , by heating to dull red then quench in water?
I believe there are better choices then 732 silicone.
Dow Corning® 732 RTV Multi-Purpose Sealant
General-purpose sealing and bonding as a space-filling rubber adhesive or a formed-in-place gasket
USES
Dow Corning1'1 732 RTV Multi-Purpose Sealant is designed for a number of diverse sealing and bonding applications. This sealant can be used for:
•Adhering auto, aircraft and appliance trim, including metal, fabric and fabric-backed plastics
•Bonding gaskets in heating and refrigeration units
•Attaching screwless brackets, nameplates, signs and sign letters
•Sealing windows in oven doors and flues on gas appliances, flanged pipe joints and access doors
•Providing formed-in-place gaskets for gear boxes, compressors and pumps
•Sealing trailers and truck cabs
•Bonding and sealing appliance parts
•Sealing marine cabins and windows
•Filleting and caulking joints in sheet metal stacks, duct work and equipment housings
•Protecting components from moisture from frequent wash downs or weathering
•Sealing aircraft galleys and interiors
at room temperature by reaction with moisture in the air to produce a durable, flexible silicone rubber.
USE LIMITATIONS
Dow Corning 732 RTV Multi-Purpose Sealant is not recommended:
•For continuous underwater immersion where adhesion or structural bonding is required
•On concrete, brick, mortar or other masonry surfaces
•*For bonding uncured sealant directly to hot surfaces
•On surfaces to be painted; paints do not adhere well to sealant (paint before applying sealant)
•On materials such as impreg*nated woods or oil-based caulks that bleed oils
•In totally confined areas; atmos*pheric moisture is required for cure
•On Teflon1 coated materials, polyethylene, polypropylene or methylmethacrylate (Plexiglas2); sealant will not adhere well
•On or near sensitive metals such as copper, brass, zinc, carbon steel, galvanized iron or magnesium; these metals may be corroded, especially in confined cure conditions, due to the acetic acid released during the cure