AnsonJames wrote:
I very much doubt a 25 year old silicone mould would be usable.
Silicone becomes brittle after a certain period of time.
My friend Ian made a full size R2, all the moulds were GE silicone.
He made one cast out of the moulds and put them into storage.
When he went to use the mould again he went to line it up in the Fibreglass case and piece literally just tore out.
Now you can easily tear pieces of the rubber out with your fingers.
The oils in the rubber dissipate over time.
Depends on what type of casting material u use, how many castings you pull, how it was stored and most importand: release agents.
Silicone doesn't need release agents when casting things out of it but laminating resin (polyester) is very aggressive and can literally bite into the silicone after a time, if no release agents are used to protect the silicone.
Was it tin cure? platinum silicone? urethane mold? I don't know