A Guide For Using Thermoplastic For Setting Stones

Jewelry 101 - How to use thermoplastic for stone settingsThe world of jewelry making contains all sorts of tools, trinkets, and materials. If you want to bring your artistic visions to life — you’ll need supplies to help you. In this guide, you’ll learn an important skill for creating jewelry: how to use thermoplastic for setting stones.

What is thermoplastic used for? Well, many jewelry makers work with a variety of gemstones and beads. Thermoplastic enables jewelry makers to affix these small embellishments securely into jewelry pieces.

Thermoplastic acts as an adhesive, almost like a glue, to hold your jewelry in place to secure gemstones. Unlike glue, you can easily remove this polymer from your design.

As you can see, no jewelry maker’s kit is complete without thermoplastic. If you haven’t heard of thermoplastic, or if the name itself sounds intimidating, we’re going to show you just how easy it is to use!

What is Thermoplastic?

Thermoplastic is a material used to bond materials together. It is a polymer (binding agent) and type of plastic that is malleable when hot and hard when cold. This makes it a great agent for setting stones into jewelry! Not only will thermoplastic secure the stones into a setting, but it makes working with the materials easy. In essence, you can mold, move, and manipulate your materials into place until they are exactly as you envision them.

There are several options for thermoplastic, but two of the most popular for jewelry making include:

  1. Jett Basic Fixturing Compound by Rio Grande
  2. Thermo-Loc by GRS

Once you have your thermoplastic in hand, there are several ways to use it — from securing stones to protecting the shape of your jewelry item.

Use Thermoplastic to Help With:


  • Setting stones into jewelry

  • Holding work securely while drilling

  • Securing a pendant, bracelet piece, earring or base metal into place

  • Placing into a bench block for easy accessibility

  • Minimize vibration to prevent mistakes

  • Setting gemstones into small items like rings and earrings

  • Supporting the shape of the jewelry item so that it won’t deform while setting

As you can imagine, these features make thermoplastic an excellent agent for setting stones. Here’s how you can use thermoplastic for setting stones into jewelry.

How To Use Thermoplastic for Stone Setting

Ready to set your stones into place with thermoplastic? Here’s a step by step guide to walk you through the process. You can fasten necklace pendants, earring metals, bracelets, and all sorts of base metals to thermoplastic. In this example, we’ll show you how to secure an earring pendant into thermoplastic to apply gemstones. However, you can easily follow these steps for any base metal you plan to affix with gemstones.


Step 1 - Start with Boiling Water

Pour hot water into a glass jar or crockpot. It’s best to avoid using a plastic container, which can easily melt and stick to the sides of the container.

Step 2 - Add the Thermoplastic

Pour 1-2 tablespoons of white thermoplastic beads into the hot water. After about 20 seconds of soaking, the thermoplastic beads will melt into a transparent blob. When you pull it from the hot water, it will be hot, so be careful not to burn yourself. If it helps, you can use a spoon to hold the blob instead of your fingers.

Step 3 - Make A Mold

Once the thermoplastic is cool enough to handle, mold it into a ball with your hands, then squeeze the base of it into a T shape. The shape should be straight and parallel. You can use a wet ring clamp to crimp out a straight line perpendicular to the base of the thermoplastic.

Step 4 - Harden the Mold

Now, dunk the thermoplastic mold into ice water to harden the shape. Once it’s nice and solidified, remove it from the ice water.
A Guide For Using Thermoplastic For Setting Stones

Step 5 - Secure the Pendant or Base Metal

Hold your thermoplastic by the T, and gently place the base of the piece into the hot water again for a few seconds. Once the base is soft, you can remove the thermoplastic and then secure your earring pendant into the base of the thermoplastic. Use your finger to manipulate the base of the thermoplastic around the edge of the pendant to secure it into place. The pendant edges should be flush against the thermoplastic, taking care not to overwhelm the pendant. Essentially, you want the pendant to be level with the thermoplastic base.

Step 6 - One Last Dunk

Once the pendant is perfectly aligned flat against the thermoplastic, you’ll dunk it into the cold water once more for 10-20 seconds.

Step 7 - Add the Stones

Now you are ready to add the stones! Secure the thermoplastic into a ring clamp or fastening tool of choice and start adding your gemstones. You’ll notice how much easier it is to set the stones with the thermoplastic. Once finished, you’ll need to remove your pendant from the thermoplastic.

After you’ve finished setting your stones, you can either clean up or reuse the thermoplastic mold. If you want to make another mold, simply dip the thermoplastic back into hot water, which will soften it and enable you to reshape a new mold.

Ready to Clean Up?

Now that you know how to use thermoplastic for stone setting, it’s time to remove the pendant and clean up. Ultimately, you’re going to repeat the same steps you used to secure the pendant to the thermoplastic, with minor tweaks. Here’s how:

Pour hot water into a bowl and dunk the thermoplastic into the hot bath for a few seconds. Use tongs to remove the thermoplastic, which should be malleable enough to remove the pendant. Unfortunately, there will be residue sticking to the pendant, which you can remove with a toothpick. Keep dunking the pendant into the hot water until all of the thermoplastic is completely removed.

That wasn’t so hard, was it? Working with thermoplastic is an easy technique to master. The great thing about this malleable material is that it enables you to bring your jewelry designs to life with ease! If your designs heavily incorporate embellishments like beads and gemstones, you’ll definitely want to keep this guide handy!

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