mark poulson Posted June 27, 2011 Report Share Posted June 27, 2011 I have a soft plastic swimbait that I want to use as a master to make an RTV mold. It has some deep detailing. What kind of release agent should I use so the RTV doesn't bond to the plastic, and which RTV can I buy in small quantity that's relatively cheap? I need about 12 cu. inches of RTV for each mold. If the mold works out, I'll probably make three more, so I can pour multiple baits from the same batch of plastic, but I don't plan to make a lot of molds, so I don't want to buy a huge amount. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Smallie Posted June 27, 2011 Report Share Posted June 27, 2011 I have a soft plastic swimbait that I want to use as a master to make an RTV mold. It has some deep detailing. What kind of release agent should I use so the RTV doesn't bond to the plastic, and which RTV can I buy in small quantity that's relatively cheap? I need about 12 cu. inches of RTV for each mold. If the mold works out, I'll probably make three more, so I can pour multiple baits from the same batch of plastic, but I don't plan to make a lot of molds, so I don't want to buy a huge amount. Thanks in advance. I use Oomoo25 from Smooth-on. Its about 30 bucks for a trial size. You don't need a mold release for making a rtv mold from a plastic master but if the master is not shiny, you can spray some Pam on it to get it "glossy" Quote Link to comment Share on other sites More sharing options...
toadfrog Posted June 27, 2011 Report Share Posted June 27, 2011 I second the above . But I might add that you can use 100% silicone that is about 3.65 a tube Just add about 1/8 tsp water per tube as you mix . It will make it set up fast so don't linger around to long before you get the master in. depending on how thick the mold is 15 minutes to an hour it is set up . You do need to set it in the sun an hour or so to make sure the water is completely vaporized . You can pour a lot of baits with it and is the cheapest way I know to experiment. Quote Link to comment Share on other sites More sharing options...
longhorn Posted June 27, 2011 Report Share Posted June 27, 2011 I've used both Oomoo 25 and 30 and have had great success. No release agent needed. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 27, 2011 Author Report Share Posted June 27, 2011 Thanks. I was thinking about silicone caulking, but the details are so small I was afraid I'd never be able to get the master back out of the mold. I'll check out the Oomoo from Smoothon. Where in the world did they get that name? Quote Link to comment Share on other sites More sharing options...
nedyarb Posted June 27, 2011 Report Share Posted June 27, 2011 I made a caulk rtv mold last week and it worked great. The only problem I see with using it for a swimbait, would be pushing it down into the silicone, seems like it would smash the tail down, and cast it at an odd angle. But I don't know for sure. Quote Link to comment Share on other sites More sharing options...
toadfrog Posted June 27, 2011 Report Share Posted June 27, 2011 I made a caulk rtv mold last week and it worked great. The only problem I see with using it for a swimbait, would be pushing it down into the silicone, seems like it would smash the tail down, and cast it at an odd angle. But I don't know for sure. Yoy have to glue the swim bait to the press board . I used pvc pipe glue . Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 27, 2011 Author Report Share Posted June 27, 2011 I always glue my masters down if they are flat topped, like this swimbait. I guess I'll give the caulking a try. I have several tubes left over from work. I'll let you guys know how it works out. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
