I have been considering making myself a silicone heart mold for a few months. In my collection there are a few hearts,that I kept trying to make work for me by manipulating the clay after removing it from the mold. I could never get quite the right shape. I have made free formed hearts before, and I like the look of these and enjoy creating them,but I still had a need for a mold. I needed to be able to press clay into a mold to help create a smooth,flat surface when working with a faux stone technique for example. I chose silicone rubber as the material to make a mold from instead of polymer clay because I wanted to use the mold for resin pours as well as polymer clay projects.
I have attempted making my own rubber molding compound from a tutorial I came across on a blog, using silicone from the hardware store and cornstarch. I did not have great outcomes the two times I tried, so now I use Castin’ Craft easy molding putty. I favor their epoxy resin so I decided to try them, it’s the first brand that I tried and the only brand I have tried 🙂 I have had great experiences with it, so I saw no reason to experiment with another brand. One of the cons with this particular product, is you have a fairly short window of time to get the mold properly positioned before the putty begins to set and harden. I have always managed to get my molds set in time, but I make sure I have everything I may need in reach before I begin.
For this particular molding project I need to create the actual shape that I want to create a mold of. To prevent distorting the clay after cutting, I am working on a ceramic tile that I can place directly on the baking tray in the oven.(You can use a clean sheet of paper that fits on your baking tray if you do not have a ceramic tile.)
I want my heart to have a thicker edge so I am going to run a layer of clay through my pasta machine on level 1 and another layer on level 3, and lay them on top of one another.I roll over it pressing lightly to remove any air bubbles. I want my mold to produce a copy with a slightly domed/rounded top. To achieve this, before cutting my clay I will lay a sheet of plastic wrap over the top, and remember, the thicker your stack of clay the more of a dome you will have in the end.
I am going to use my heart cutter of course, but you can use any shape cutter you like. After my heart is cut I bake it according to the directions on the package. After it has cooled down, I sand the edges a bit and prepare my area for creating the silicone mold. (TIP: I always prepare a few extra items in the event I mix too much molding compound, or if I have room around the original item and can fit something else in.)
This particular putty requires you to mix equal portions of two different parts until they are a uniform color and then you press it around the item you are creating a mold of. Once you are sure your object is entirely covered, set it aside to cure. I let it go a little bit longer just to be on the safe side. After the silicone has cured, the original object pops right out and now I have a silicone mold, in the exact shape I was looking for and I can use it for polymer clay and epoxy resin.
If you look closely at the photo of the mold, you can see tiny bubbles. I’m not sure what I did differently to make this happen. It will not affect my polymer clay pieces but it will definitely show up on the surface of any resin I cast in it. 😦 My guess is I over mixed it??
If you have made your own silicone rubber molds with success, I would appreciate hearing about your process as well as products. I would prefer to make my own compound as it is way more cost effective 🙂 Please share with me in the Reply area below.
My Amazon affiliate link to the product I purchased :Castin’ Craft Easy Molding Putty
You may also be able to find this product at some craft stores. Michaels and Jo’Anns have carried it in the past, ask your local favorites if they have it in stock. I hunt for 40-60% off coupons to purchase pricier items like this.
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