How to Reheat Pottery

Reheating pottery is an essential process for artists and craftsmen looking to repair, refine, or rework their creations. Whether you’re aiming to restore a piece or prepare it for glazing, understanding the proper techniques ensures that the pottery remains intact and achieves the desired results. This guide will outline the fundamental steps of how to reheat pottery successfully.

Can You Safely Reheat Pottery?

Yes, you can safely reheat pottery, but it requires careful attention to avoid damage or breakage. The key is to heat the pottery gradually to prevent thermal shock, which can cause cracking or shattering. Always inspect the piece beforehand for any existing cracks or imperfections, as these can worsen during the reheating process. Additionally, using a kiln or an oven designed for ceramic work ensures even heat distribution and better control over the temperature.

Avoid extreme temperature changes, such as placing cold pottery directly into a hot oven, as this significantly increases the risk of damage. With the right precautions, reheating pottery is a safe and effective way to restore or modify your work.

Reasons for Reheating Pottery

There are several reasons why reheating pottery can be beneficial for artisans and hobbyists alike. One common reason is to fix imperfections or cracks that may have appeared after the initial firing. Reheating allows repair materials, such as glazes or fillers, to properly bond with the pottery surface. Another reason is to apply additional layers of glaze or decoration, which can enhance the appearance and durability of the piece.

Reheating is also used in the process of re-glazing older pottery to give it a refreshed and updated look. Furthermore, it can be a way to experiment with new techniques, such as adding textures or finishes, by modifying previously completed work. Ultimately, the process provides an opportunity to refine and breathe new life into ceramic creations.

10 Methods How to Reheat Pottery

1. Reheating in a Conventional Oven

One of the most practical and controlled methods for reheating pottery—especially pieces that are fully vitrified and glazed—is to use a conventional kitchen oven. Begin by ensuring the pottery is free of cracks or existing damage, as reheating may exacerbate such flaws. Place the pottery on the middle rack and start with a cold oven to avoid thermal shock. Gradually raise the temperature, typically no more than 200°F (93°C) per hour, to avoid sudden expansion.

Reaching up to 300°F–400°F (149°C–204°C) is generally sufficient if you’re reheating for drying purposes, such as removing residual moisture before a second glaze firing. Let the pottery remain at the target temperature for a sustained period before slowly cooling down in the oven to avoid cracking. This method is suitable for DIY artists and home ceramicists who need to re-dry or preheat bisque-fired pieces.

2. Using a Kiln for Controlled Reheating

Reheating pottery in a kiln provides the most precise and consistent results, especially when preparing a piece for refiring or reglazing. A digital or programmable kiln allows for controlled ramp-up and cool-down sequences, minimizing the risk of thermal shock. Start with a low temperature and use a slow ramp—perhaps 150°F (65°C) per hour—until you reach your desired temperature.

Depending on your goal (e.g., touch-up glazing or stress relieving), you might reheat up to cone 06 (approximately 1830°F / 999°C) or stop short at bisque ranges. Ensure the pottery is dry before placing it in the kiln to prevent steam expansion cracks. This method is particularly recommended for studio professionals and experienced potters who understand firing schedules and kiln atmospheres.

3. Microwave Reheating for Small Repairs

Microwave reheating should be approached with great caution and only used for very specific applications, such as drying tiny ceramic pieces or softening materials like epoxy used in pottery repairs. Never microwave metallic or glazed ceramics unless labeled microwave-safe, as metal can spark and glazed pieces may overheat unevenly.

Place the pottery with a cup of water in the microwave to diffuse the energy and avoid overheating. Limit the time to short 30-second intervals, checking for heat buildup. This method is not suited for general reheating but may serve a niche role in warming up materials for restoration or testing.

4. Heat Gun Application for Surface Drying

A heat gun offers pinpointed reheating and is often used to dry pottery surfaces before painting, glazing, or further firing. Hold the gun 6 to 12 inches away from the surface and move it continuously to avoid scorching. This method is best for removing surface moisture or warming a pottery piece slightly before applying a glaze or repair material. Use in a well-ventilated area and avoid prolonged exposure on any one spot. Heat guns offer great flexibility and control for ceramic hobbyists and restoration experts working on touch-ups or surface modifications.

5. Reheating on a Stove or Hot Plate (With Caution)

While not a conventional method, reheating pottery on a stove or hot plate may be used to warm small, heat-resistant items such as clay cooking pots or traditional terracotta pieces. Place the pottery on a cold burner and gradually increase the heat to avoid shocking the ceramic structure. Low to medium heat should suffice for warming purposes—such as seasoning clay cookware or reviving a cold piece for use. Always monitor closely and never leave pottery unattended on direct heat. This method is particularly relevant to cultural or culinary uses where traditional ceramics are involved.

6. Using a Dehydrator or Warm Box

For potters working with greenware or bisque pieces that need slow reheating to remove moisture, a food dehydrator or homemade warm box offers a gentle and uniform method. Set the temperature between 100°F and 150°F (38°C–65°C) and place the pottery inside for several hours. This method helps prevent warping or cracking during subsequent kiln firings by ensuring the piece is thoroughly dry. Warm boxes, often homemade from wood and heat bulbs, are common in studios dealing with delicate pieces or high humidity environments.

7. Infrared Lamp for Targeted Reheating

Infrared lamps, commonly used in therapeutic or industrial settings, can be repurposed to warm pottery in targeted areas. These lamps emit radiant heat and can raise the temperature of a specific zone without affecting the entire piece. They’re ideal for warming up repaired sections or slowly heating localized regions before applying touch-up glazes. Infrared heat can also be used in conjunction with slow drying to accelerate moisture removal in greenware. Be careful to avoid overexposure which could cause uneven heating or stress.

8. Sun-Drying and Ambient Heat

If time is not a constraint, natural sunlight and ambient heat are safe and energy-efficient ways to reheat or dry pottery, especially greenware or newly cleaned bisque pieces. Set the pottery in a bright, sunlit area shielded from drafts and temperature fluctuations. Turn the piece occasionally to ensure even heating. Although this method is slow, it is gentle and nearly risk-free, ideal for preparing delicate items for later kiln firing or for those in environments without access to powered heating tools.

9. Warm Water Bath for Functional Pottery

Reheating functional pottery, such as a clay teapot or serving dish, can be done using a warm water bath. Place the item in a sink or basin filled with warm—not boiling—water, and allow it to acclimate for 10–15 minutes. This is especially effective when you’re trying to prevent cold shock during the serving of hot liquids or food. Never immerse cracked or fragile pottery in water, as moisture ingress can worsen internal weaknesses. This approach is ideal for clay cookware or drinkware prior to use.

10. Fireplace or Hearth Reheating (Traditional Method)

In traditional or off-grid environments, pottery is sometimes reheated using a hearth or fireplace. To do this safely, embed the pottery in warm ash or place it near—but not directly in—the fire. The radiant and convective heat warms the piece gradually, mimicking old-world reheating techniques used for clay cookware. Rotate the piece regularly to ensure even heating. This method should be used only with thick-walled, fire-resistant pottery and in environments where you can supervise closely. It reconnects modern potters to historical craftsmanship and can be a part of cultural practices or demonstrations.

Troubleshooting Common Issues

When using traditional techniques to heat pottery, a few common issues may arise. One frequent problem is cracking, which often occurs if the pottery heats too quickly or unevenly. To avoid this, always ensure the piece is rotated regularly and introduced to heat gradually. Another issue is discoloration, which might happen if ash or soot clings to the surface during the process. To minimize this, clean the pottery thoroughly before starting and monitor its placement to reduce exposure to direct flames or heavy soot.

Additionally, structural weakness can sometimes appear after heating, especially if the pottery wasn’t fired properly during its initial creation. Inspect pieces for any pre-existing cracks or defects before reheating. Lastly, maintaining the proper type of clay is crucial—standard household ceramics may not withstand the stresses of traditional reheating methods. Always ensure you are working with fire-resistant, thick-walled pottery specifically designed for such techniques.

Conclusion

Reheating pottery is a nuanced process, dependent on the purpose—be it drying, repairing, refiring, or warming for functional use. Whether you choose a modern kiln, a simple oven, or a traditional fireplace, understanding the thermal properties of ceramics and proceeding with patience are key to maintaining the integrity of the piece. Thanks for reading our blog post on how to reheat pottery! We hope you found it helpful and informative.