How to Use Resin Molds with Deep Pour Epoxy: Tips for Thick Casts and Embedding

Deep pour epoxy resin opens up a world of possibilities for crafters who want to create thick, clear casts or embed objects like flowers, photos, and trinkets. Unlike standard casting resins that require thin layers, deep pour epoxy can be poured in thicker sections—up to 2 inches at a time—saving you time and reducing the risk of cloudy layers. However, working with deep pour epoxy in resin molds requires a slightly different approach to avoid bubbles, overheating, and uneven curing.

Whether you are making chunky paperweights, decorative coasters, or custom jewelry pendants, understanding how to pair deep pour epoxy with the right molds and techniques is essential. In this guide, we will walk through the best practices for using deep pour epoxy with silicone molds, from preparation to demolding, so you can achieve crystal-clear results every time.

Why Choose Deep Pour Epoxy for Thick Casts?

Deep pour epoxy is specifically formulated to handle the heat generated during the curing process. When epoxy cures, it produces an exothermic reaction—heat that builds up inside the resin. Standard epoxy can overheat and crack or yellow if poured too thick, but deep pour epoxy is designed to dissipate that heat safely, allowing you to pour layers up to 2 inches deep in a single pour. This makes it ideal for casting large, solid objects like bookends, paperweights, or decorative blocks.

Another advantage is clarity. High-quality deep pour epoxy, such as the CRAFT RESIN Deep Pour Up to 2" Casting Epoxy 6 Gallon, cures with minimal bubbles and a crystal-clear finish. This clarity is especially important when you are embedding items like dried flowers or photos, as any cloudiness would obscure the embedded object. By using a deep pour formula, you also reduce the number of layers you need to pour, which speeds up your project and minimizes the risk of dust or debris settling between layers.

• Deep pour epoxy can be poured up to 2 inches thick in one go, reducing layering time.
• It generates less heat per volume compared to standard epoxy, preventing cracks.
• Crystal-clear finish makes it perfect for embedding and displaying objects.

Choosing the Right Resin Molds for Deep Pour Projects

Not all resin molds are suitable for deep pours. Silicone molds are the best choice because they are flexible, non-stick, and can withstand the heat generated by thick epoxy pours. Rigid plastic or metal molds can trap heat and cause the epoxy to cure unevenly or crack. When selecting molds, look for those made from high-quality silicone with smooth interiors—this ensures easy demolding and a glossy finish on your cast.

For thick casts, consider molds with simple, open shapes like cubes, cylinders, or geometric forms. Detailed molds can work, but you need to ensure the epoxy flows into all crevices. For example, the Mini 3D Pumpkin Molds - set of 3 are great for small, thick casts, while the 3D Skull Resin Molds - Set of 3 can be used for deeper, more sculptural pieces. If you are embedding objects, choose molds that are slightly larger than the item you are embedding to allow for a clear epoxy border.

• Silicone molds are ideal for deep pours due to their flexibility and heat resistance.
• Simple, open shapes are easier to pour and demold for thick casts.
• Ensure the mold is deep enough to accommodate both the embedded object and a clear epoxy layer.

Preparing Your Workspace and Materials

Before mixing your deep pour epoxy, set up a clean, dust-free workspace. Use a level surface to ensure your mold sits flat—this prevents the epoxy from pooling to one side. Wipe down your silicone mold with a lint-free cloth and isopropyl alcohol to remove any dust or residue. If you are embedding objects, make sure they are completely dry and sealed (for organic items like flowers) to prevent discoloration or air bubbles.

Measure your epoxy components carefully using a digital scale. Deep pour epoxies typically use a 2:1 ratio by volume or weight—check the manufacturer's instructions. For the CRAFT RESIN Deep Pour Up to 2" Casting Epoxy 6 Gallon, the mix ratio is 2:1. Stir slowly and thoroughly for at least 3 minutes, scraping the sides and bottom of your mixing cup. Avoid whipping air into the mixture. After mixing, let the epoxy sit for a few minutes to allow bubbles to rise to the surface.

• Clean your mold with isopropyl alcohol to ensure a bubble-free surface.
• Use a digital scale for accurate measurement of epoxy resin and hardener.
• Stir slowly to minimize air entrapment—no vigorous whisking!

Pouring Techniques for Thick Casts and Embedding

When pouring deep pour epoxy into your resin mold, pour slowly and in a thin stream from a low height. This helps break up any bubbles and prevents air from being trapped. If you are embedding an object, pour a thin base layer first—about 1/4 inch deep—and let it partially cure until it becomes tacky. This base layer will hold your embedded item in place and prevent it from floating to the top. Then, carefully place your object and pour the remaining epoxy over it.

For objects that tend to float, such as dried flowers or small trinkets, you can use a toothpick or tweezers to position them after pouring. Alternatively, pour the epoxy in two stages: first a layer, then place the object, then pour the final layer. This method ensures the object is fully encased and centered. If you notice bubbles after pouring, use a heat gun or torch passed quickly over the surface to pop them. Be careful not to overheat the epoxy, as this can cause it to cure too quickly.

• Pour in a thin stream from a low height to minimize bubbles.
• Use a tacky base layer to anchor embedded objects in place.
• Pop surface bubbles with a heat gun or torch—brief passes only.

Curing and Demolding Your Deep Pour Cast

Deep pour epoxy requires a longer curing time than standard epoxy—typically 24 to 48 hours, depending on the thickness and ambient temperature. Keep your mold in a warm, stable environment (around 70-75°F) to ensure even curing. Avoid moving the mold during the first few hours, as vibrations can create bubbles. If you are pouring a very thick cast (over 1 inch), you may need to let it cure for up to 72 hours to fully harden.

Once cured, demolding is easy with silicone molds—gently flex the mold to release the epoxy. If the piece sticks, place the mold in the freezer for 10-15 minutes; the epoxy will contract slightly and pop out. After demolding, you may notice a slight haze or fingerprint marks on the surface. Buff the piece with a microfiber cloth or sand it lightly with fine-grit sandpaper (800-1200 grit) and apply a clear coat of UV resin for a glossy finish. The CRAFT RESIN UV Resin Kit with Light for Jewelry is perfect for adding a final high-shine layer to small casts.

• Cure in a warm, draft-free area for 24-72 hours depending on thickness.
• Freeze the mold briefly if the epoxy sticks—thermal contraction helps release it.
• Polish or sand the cured piece for a flawless, glass-like finish.

Deep pour epoxy combined with quality silicone molds is a game-changer for creating thick, clear casts and stunning embedded pieces. By following these tips—choosing the right mold, preparing your workspace, pouring carefully, and allowing proper curing time—you can achieve professional results every time. Ready to start your next deep pour project? Explore our selection of resin molds and deep pour epoxy to bring your creative visions to life.