Making Molds from Nature
Why I Make Molds and How I do It
Creating metal clay jewelry pieces from nature is an easy process when you know how to make molds from those natural elements. Metal clay is a clay material that can be formed with molds, carved in its dry state and fired in a kiln or torch fired until the pieces are a solid metal. This clay material has opened up design possibilities and since I'm so inspired by nature, creating jewelry pieces using metal clay and molds of natural elements just made sense. This lens will show how I make molds of the grasses and flowers that I use in making my jewelry. These molds can be used to form pieces from polymer clay or ceramic clay and I'm sure other uses as well.
All photos by Gayle Dowell
Using Polymer Clay or Sculpey Mold Maker to Make Molds
When I started making molds, I used Sculpey Moldmaker. Polymer clay can also be used. It is a great material and as can be seen in the picture below (mold is on the left with the resulting clay piece on the right), it picks up a lot of the detail of the object being molded. I've used this method for awhile, but wanted to find something a little easier to use as this method takes some time because I have to bake the clay after it is molded. I wanted to by-pass this step so that I could easily make molds as I hiked the prairies of Kansas. This molding compound makes a rigid mold that is not flexible.
Depending on how the molding compound will be used and how durable or flexible the final mold needs to be will dictate which molding compound to use. A word of caution, not all air dry modeling clay is the same. I've purchased several different brands and found them to be very different in how they hold up after drying or how well the metal clay releases from the molds. My overall best pick for a molding compound has to be the Sculpey Bake and Bend clay. It is flexible, the clay releases from the baked clay well and it picks up good detail from my grasses and flowers.
Using Air Dry Clay for Molds
Model Air Dry Modeling Clay which is an air dry clay, works well and is portable. I got the same great detail as the Sculpey Mold Maker without having to bake it. It takes a long time to dry, but I wedge my pieces between two pieces of clear glass 4" x 4" to transport with the natural element still in the clay and then I let it dry when I get home. I did find that the molds can start to deteriorate if you use a very wet clay in the molds. For me, it works well enough for my more temporary rigid molds, and I like the price as I make a lot of molds. No need to use a mold release on this one as the metal clays do not stick to the molds. In fact, using a mold release will damage the detail. I've found that spraying a clear acrylic spray over the mold helps prolong the life of the mold.
Be aware that not all air dry clay is the same. There is an air dry clay that Crayola makes and it does not hold up well as a mold.
In using Model Air Dry Modeling Clay, I always start by pressing the compound or clay between a non-stick surface and a piece of glass. Flattening the compound first before impressing your object into the compound keeps excess compound from forming over the object, or if molding a fragile object will keep the object from breaking from the pressures of the moving compound.
After I flatten the compound in step one, I arrange my natural elements on top of the clay to form a pleasing composition. It is important to make sure to stay clear of edges so the whole piece will be molded which will give more design options when molding the final project with the mold.
Next, I take a piece of clear glass and set it on top of the object to be molded which is on top of the modeling compound. I then apply just enough pressure to sink the object in the compound. Using the clear glass bevel tiles (these can be found on amazon or a craft supply store that carries stained glass supplies) allows me to see what is happening as I press and I know when to stop exerting pressure on the item and compound. Also the glass is such a slick surface that the compound does not stick to its surface. I've also used clear acrylic tiles found with rubber stamp supplies.
Depending on what I am doing at the time, I either let the compound sit with the object still in the mold compound, or I will take the natural element out as soon as I press it. If I am hiking and need to transport, I will press between two pieces of clear glass and secure with rubber bands until I get home. This protects the surface of the mold in transport. If I am home, I will take the object out of the compound and let dry. I get very little shrinkage with this clay and the mold will be rigid when dry. I usually let it dry all day and flip it over to speed up the drying time. Drying time will depend on the thickness of the mold and air humidity.
Using Silicone Putty for Mold Making
Another mold making option is Easy Mold Silicone Molding Putty for Casting and Jewelry Making 1/2 Pound. Fairly easy to use, it is fast and gives me great detail without any shrinkage. It consists of two different parts of putty that I mix together in equal portions which has to be done quickly before it sets. Then it cures in 25 minutes and it is ready to use. For portability, I divide out my clay in airtight containers before I head out on my hike. I mix the clay on site. I leave the object in the silicone and wedge between two pieces of glass until it sets. This tends to be a little more expensive and I reserve this for molds that I want to use a lot. I have molds that I made two years ago that I still use and I see no wear on them and they stay flexible. As shown in the photo below, I purchase mine from Rio Grande, but the Easy Mold Silicone Molding Putty is the same material.
With the Easy Mold Silicone Molding Putty, it is important to measure out equal amounts of the two parts of putty. Depending on the brand, it may be different in color. When these two parts are mixed together, the reaction starts and the putty starts to set up. It takes only 3-5 minutes before the putty is at a stage that it sets-up and can no longer be molded. Acting quickly to impress your object after mixing will create better results.
The rest of the process is the same as the above tutorial for the Model Air Dry Modeling Clay. Pressing the clay flat, embedding the object by exerting pressure with a piece of clear glass. Be sure to use glass that has a smooth edge for safety reasons. I use beveled glass tiles that are thick, but I've also found thick acrylic tiles in my neighborhood craft supply store. Glass can break under pressure. Set up time is about 25 minutes. The end product is a mold that is flexible, long lasting and has no shrinkage.