What Happens to Polymer Clay in the Microwave?

When you’re looking to speed up the crafting process, you may question whether the microwave is a hack others haven’t tried. It can heat frozen food and leftovers well. Why not polymer clays? The directions on Sculpey® packages say not to put the clay in the microwave, but could you use it for baking polymer clay? The short answer is no. Polymer clay’s chemical composition doesn’t react well to the radiation that the microwave employs. 

What exactly happens to the clay if it goes into a microwave? Let’s find out together.  

What Happens When You Put Polymer Clay in a Microwave?

Microwaves are designed to project electromagnetic waves onto food. These waves create movement in the fat, sugar and oil molecules. That movement produces heat, which cooks the food. Polymer clays do not contain sugar or fat molecules, but they do have oil molecules. So, if you place the clay in the microwave, a form of cooking will occur — but your creation won’t turn out the way you expect it to.

Have you ever taken food out of the microwave and noticed that some areas are hotter than others? That uneven temperature demonstrates the unbalanced distribution of heat throughout an object placed in the microwave. Polymer clays need an even distribution of heat to cook properly. 

If you place pieces of clay in the microwave, the oil molecules will cause the clay to cook unevenly. This imbalance will leave some parts of your clay cured and other areas soft. What’s more, the areas of the clay that are cooking will receive all of the microwave’s electromagnetic waves, causing overheating. Overheating makes the clay bubble. It can even burn and release a harmful airborne chemical called hydrogen chloride.

Avoiding the microwave is crucial to safe, enjoyable crafting with polymer clays.

The Best Method for Baking Polymer Clay

For the best crafting results, the oven is your go-to tool. Ovens work differently than microwaves in that they use either electricity or gas to heat up. Ovens sound off when the entire chamber has preheated and achieved a uniform temperature. Unlike microwaves, which use protruding electromagnetic waves, ovens use this temperature-monitored compartment to achieve an even bake throughout food or polymer clays. When baking polymer clay in an oven always use  an oven thermometer to ensure your oven is at the temp you think it is to avoid burning or undertaking clay.

To achieve a perfect, even bake, it’s important to follow the instructions on your polymer clay’s packaging. It should specify the oven temperature and bake time. Our packaging recommends varying oven temperatures and times based on the types of clays you are using. For example, you should bake Sculpey III® at 275 degrees Fahrenheit for 15 minutes per 1/4-inch thickness. You can find baking times and temperatures for other products on our FAQ page if you don’t have the packaging handy.

Sculpey® Offers High-Quality Clay Materials to Crafters

Sculpey® has materials and tools for every clay crafter, whether you’re a beginner or a pro. We offer a range of high-quality, dependable clays to help you achieve your creative vision. Browse our clay products today!

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