Can mold release go bad AND how to glue Silicon

[Darkproductions]

OK so I am working on the mold for the Emperor's Champion and I have run into a snag. The mold has ripped and I really dont relish the idea of redoing a 4 part silicon mold. Question 1: There is a rip right in the forehead of the helmet about an inch and a half long. is there a way to fix this? How? During this process I used a spray mold release between my silicon layers and it didnt separate at all. Can mold release expire? Thanks for the assistance.

~Newsome

 

[Too Much Garlic]

Cyanoacrylate glue can glue silicone - what is used to glue vinyl model kits - but it can rip if pulled too hard. It's isn't a permanent fix, but it works fine for temporary fixes, such as for casting.

 

[bookface]

Smooth-on sell a glue for silicone that works really well. The alternative is trying to patch it with fresh silicone, used sparingly (essentially, as a glue). I've not seen mould release go bad, did you use enough of it? Whenever I'm doing a multiple part mould, I put several coats of the mould release on there before the next load of silicone.

Even after mould release is applied, it won't just peel apart really easily, you need to find the seam and apply some pressure. Once it starts to separate, it's not too bad, but initially it can be a pain.

 

[Zantergog]

I've had mold release not work for me on a two part silicone mold. I had to scapel the two halfs apart, as Bookface said, I don't think I aplied enough or didnt allow it to cure well. Normally spray the release then brush in with a soft brush then spray in again and wait 2- 3 mins between coats. For some molds I have used a thicker wax, like a boot wax , warmed up and painted on the result is a much thicker wax, I would't use it on surface detail as it too filing. With silicone to silicone release it can be good. Always test !