Mold ?'s/Release agents

[rookiepourer]

I am currenty working on making my own molds. I plan on buying some RTV silicone to use for the mold. I have two worms/creature that I have made from Sculpey clay. : The first question is in coating the master. : Will clear coat paint work for the sealer? The second is Do I need a release agent on the masters before making the mold? Thanks for the info

Mark

[AlbyDogGone]

I have just started doing the exact same thing, the first time I bought casting resin from Hobby Lobby and that was WAY too expensive. Like 20 bucks for 32 oz, wally mart has them for 8 bucks for 32 oz...anyways..I used the casting resin and poured it on the hard sculpey(that is really good stuff and really pliable and easy too use by the way), I didn't use any releasing agent and that went wayyy bad...tried it again with some cleaner stuff I found that looked like it might work..foiled again. So then I used the Wal-mart bondo type resin and then sprayed the new master I had to make with Pam cooking spray and they came out beautifully. I was thinking also about sealing the master's but not sure with what yet. I too would like some ideas if anyone has them...anyways hope a little bit of this ino helps and I too would like to know of other ideas if anyone has them?

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[Mattman]

Most clear coats will work fine for a sealer. You mostly need to get rid of slight imperfections that will allow the RTV to get some "tooth" on the master. There is also a special epoxy that you can use. Drawing a blank on its name right now. But it's used in a lot of molding and casting shops to seal up the master and create a real durable finish. And I'm talking about stuff like thermoforming 3/8" thick polyethelyne in production runs over your master, not just making RTV's. I think that's waaay overkill for this though.

Release agents are always a good idea. You can make your own by mixing up some petroleum jelly and naptha and brush it on. Or you can buy several different kinds already in the can.