Polymer clay is a versatile crafting material that can be used to make a variety of objects. It’s super friendly to crafters because you can sculpt whatever you’d like from the soft clay and then cure it in your home oven to create a finished piece of ‘ceramic.’
Is polymer clay waterproof? Like traditional ceramics, polymer clay is waterproof when it is cured, which means it can hold water and you can wash it. However, waterproof isn’t the same as food-safe, so it should definitely not be used to handle food or drinks.
In this post, we’ll take a look at polymer clay and its water-resistance properties. We’ll also provide some tips on how to make your polymer clay creations more durable.
What Is Polymer Clay?
Polymer clay is a material that has been gaining popularity in recent years. It’s largely due to its flexibility and ability to hold shape, which makes it easy to mold and work with.
Interestingly enough, polymer clay does not contain any clay minerals. It is actually made from liquid plasticizer and PVC resin, which means it is essentially plastic.
The polymers create cross-link throughout the structure, giving polymer clay greater durability and making it easier to mold, while the filters allow the clay to retain its shape.
This combination results in clay that is much more versatile than traditional clay. It can transform into any shape and then cured in your home oven at 230 – 275°F, which is much lower and more practical than the cumbersome kiln firing of ceramics (over 2,124℉).
This advantage makes polymer clay friendlier to casual crafters since they can make anything out of polymer clay and cure it in the oven. That’s why a lot of small businesses making small-batch jewelry and decor pieces love using polymer clay (check out our article for the best polymer clay for making jewelry).
Polymer clay is quite useful in creating jewelry, figurines, and sculptures. It is available in many colors, and you can also paint and decorate your polymer clay piece after it is completely cured.
Is Polymer Clay Waterproof?
Although it is cured at a much lower temperature compared to traditional ceramics, polymer clay does share some of the same characteristics as ceramics. Namely, polymer clay is super durable and waterproof after it is cured.
Since polymer clay is essentially plastic, it won’t even soak up water (unlike unglazed ceramics and air-dry clay). This means you can use polymer clay on a wide range of applications, even outdoor decor pieces that need to withstand harsh environments like humidity, rain, and snow.
That said, prolonged exposure to the elements can lead polymer clay to develop a chalky surface, especially if it has a darker color. This is partly due to the clay’s porous nature and the damaging effects of UV rays.
Do You Need To Seal Polymer Clay?
Polymer clay is a wonderful material because it’s both durable and versatile. The finished product can be super durable and waterproof, without any need for a special sealant to protect against water damage or other elements.
In fact, whatever sealant you use will probably break down before polymers would. The sealant will cloud over, hold brush strokes, or peel off, turning your attractive polymer clay project into an unappealing mess.
The only reason you might want to seal your polymer clay is if there’s something else on the surface of it that needs protection. Paint, foil, and other embellishments may not be so lucky when exposed for too long – they could peel away from their base easily without a sealant.
A sealant may also be able to add a different finish to your polymer clay project. If you want the polymer clay to look glossy, matte, mirror-like, or sparkly, using a sealer is the best way to give the polymer clay a different finish.
If you opt to use a sealer, make sure to use a brush-on sealer rather than a spray sealer. A lot of spray sealers contain elements that don’t react well with the plasticizer, resulting in an undesirable finish.
If you want to use a sealer on polymer clay, make sure to use a waterproof sealer. Most sealers are water-resistant, but that’s definitely not strong enough, and your sealer will wear out before your polymer clay creations. Using a varnish or epoxy sealer would be your best bet.
Regardless of the sealer that you choose, make sure to patch-test the sealer on the polymer clay first before putting it all over the finished project.
Elements in the sealer and the polymer clay may react poorly with one another, so testing the product first is the best way to see which one will work, or you may risk ruining your entire creation altogether.
Is Polymer Clay Food Safe?
Polymer clay is non-toxic and easy to use, making it a great choice for crafting projects with children. Similar to traditional ceramics, polymer clay will become super durable and waterproof after curing, so it can be used to hold liquids.
However, unlike traditional ceramics, polymer clay is not food safe. This means that it should not be used to make plates, bowls, mugs, or other items that will need to handle food or drinks.
While the clay itself is non-toxic, the chemicals in it can leach into food and cause illness. For this reason, it is important to use polymer clay only for non-food items.
When the clay is being cured in the oven, it can also release hydrogen chloride gas, which is not safe to ingest. It is important that you don’t bake food at the same time as your polymer clay, and make sure your kitchen is properly ventilated when the clay is being baked.
Can You Wash Polymer Clay?
Polymer clay is a popular material for crafting because it is easy to work with and very versatile. One of the best features of polymer clay is that it is waterproof, which means it can be washed without fear of damage.
However, you should avoid washing polymer clay in the dishwasher because the dishwasher uses both heat and water to sanitize your dishes. Although the dishwasher only uses a temperature of about 130-140°F, a cycle can still cause the clay to warp or melt.
If you need to clean your polymer clay project, simply wash it by hand using warm water and mild soap. Once you have finished washing, allow the clay to air dry completely, or wipe it down with a lint-free cloth to restore it to its original condition.
Can You Air Dry Polymer Clay?
Both traditional clay and air-dry clay can be air-dried to harden. With traditional clay, letting the pottery dry out is necessary before the kiln firing so that the ceramics will cure properly.
With air-dry clay, your product will cure at room temperature after a few days, although it won’t be as durable or waterproof as traditional ceramics and polymer clay. It can also crack easily while curing.
Polymer clay is soft and pliable when it first comes out of the box and will only harden when exposed to heat. Because of this property, polymer clay can be oven-baked to create permanent, solid shapes.
Curing polymer clay correctly is essential to ensure that it will not break or crumble over time. The clay must be baked at the correct temperature for the correct amount of time. If it is not, the clay may not cure properly and could become brittle.
Without the oven heat, the polymer won’t dry out, and you’ll be able to shape it as much as you want until it is cured in the oven.
Can You Recycle Polymer Clay?
Traditional mineral clay is a pretty environmentally friendly material. The clay, if it’s not been kiln fired, can be washed and used over and over again.
In addition, ceramic products can be crushed and recycled into a range of useful products, such as aggregate for concrete or insulation for homes. As a result, ceramics are an environmentally friendly material that can be reused or recycled at the end of their lifespan.
Since polymer clay is often thought of as a type of clay, a lot of people believe that it’s also environmentally friendly. This is not true.
Polymer clay is made from polyvinyl chloride (PVC), plasticizer, and fillers. While it is a popular material for crafting, it is not very environmentally friendly. Once it is used, it can’t be recycled like other types of plastic.
While polymer clay may be fun to work with, it is important to be aware of its environmental impact before using it.
That means you should use the clay responsibly, don’t waste the product, and don’t fire the clay unless you are completely happy with its shape. Once fired, the clay won’t be reusable or recyclable.
That said, polymer clay is mainly used in small batches by small businesses and DIY crafters, so the environmental footprints are small. You don’t have to stop using polymer clay altogether, but make sure not to waste the product and dispose of it properly when you need to.