Problem with silicone mold

[RDW]

Hey Everyone,

I tried making my first silicone mold and I thought everything was going fine until I removed it from the glass dish that I used. The silicone was set up good except where it made contact with the baits. To start I glued the soft baits to the dish making sure that they were in complete contact with the bottom. I then mixed the silicone as directed and slowly poured it over the baits so that the silicone slowly crawled across the dish. The next day I was going to demold it but the weather was so nice that I did some catching up on some work around my farm that was way over due. I did not demold it until today and it was not cured at all where it made contact with the baits. The silicone I used was Smooth-Sil 930 from smooth-on. That is what my local distributor said that I should use. Is he right? Did I leave it too long before demolding it? Any help that you all can give me will be appreciated. Sorry for the long post. I just wanted to give all the info that I could.

Thanks!

Rick Watson

[dtrs5kprs]

You should not be able to leave it "too long". Most RTV cures better in contact with glass, metal, or hard plastic. Areas touching soft plastic may cure more slowly...especially if the RTV is either incorrectly mixed or mixed without enough hardener. Using Lurecraft RTV I normally add an additional volume of hardener to get a more "solid" mold that cures faster.

Had some of this problem making the soft master molds from aluminum originals.

[camrynekai]

You cant use silicone over cyberflex or berkley power worms (it will start to melt the baits and not cure). I only use silicone from lurecraft, mainly due to FORMALDEHYDE. The silicone lurecraft sells will NOT give off any formaldehyde until 450 deg. Most other silicone blends give off allot of formaldehyde starting at 250 deg. Lurecraft is much safer to use with heated plastic.