capt mike Posted March 3, 2013 Report Share Posted March 3, 2013 I have been making swimbait masters with soft clay and making molds with silicone. Since I am shaping the master with my hands, the mold is picking up fingerprints etc., which leaves the surface of my poured baits cloudy and dull. I remember reading somewhere that rubbing silicone in the inside of the mold would fill in the crevices and fingerprints. I tried rubbing some 100% silicone in the mold but it would not set and stayed sticky. What can I do for my molds? Really do want to get a better surface. I did search a few times, but have not seen the post I was looking for. Quote Link to comment Share on other sites More sharing options...
bflp Posted March 3, 2013 Report Share Posted March 3, 2013 Have you tried baking the clay, and then sanding it down once its hard? I have the same issues with pop molds, but I can't bake the clay due to the hard mold, but since you are using silicone that won't be an issue. Quote Link to comment Share on other sites More sharing options...
wchilton Posted March 3, 2013 Report Share Posted March 3, 2013 If you are using polymer clay (like sculpey) baking hardens it and then it can be sanded or painted. If you use modeling clay, baking will just melt it since it's basically a mixture of clay, parafin, and oil. I've actually been able to coat modeling clay masters with acrylic floor wax. You could probably just paint them with a water-based paint that dries to a gloss finish. Seems weird to paint something so soft, but the paint doesn't really have to "stick", only stay in place long enough to make the mold. If you want to try making your existing silicone mold smooth, I think your best bet is to use the same RTV silicone that you made the mold out of. Clean the mold cavity real well, make sure it's "dry" and then paint on a thin layer of the RTV after mixing in the appropriate amount of catalyst. Silicone sticks permanently to cured silicone so you should have no adhesion problems. I've actually used cut up pieces of "reject" silicone molds as filler material when making a new silicone mold. Works fine and reduces the amount of new RTV I have to use. Quote Link to comment Share on other sites More sharing options...
capt mike Posted March 4, 2013 Author Report Share Posted March 4, 2013 Using modeling clay. I will try brushing the mold max inside the cavity. That makes perfect sense. I know that will stick for sure. Should I brush it in or rub in with fingers? Quote Link to comment Share on other sites More sharing options...
wchilton Posted March 5, 2013 Report Share Posted March 5, 2013 Using modeling clay. I will try brushing the mold max inside the cavity. That makes perfect sense. I know that will stick for sure. Should I brush it in or rub in with fingers? Either way. Uncured RTV is pretty gooey so I'd use a nitrile exam glove. Make sure you mix it really well and I'd put a little spot of the RTV on the mold but outside the cavity to test for it curing. Sometimes really thin RTV takes longer to cure so give it plenty of time. Putting it in a warm place helps too. What I've done it put it in the oven with just the light on overnight. Good Luck. Quote Link to comment Share on other sites More sharing options...
