Things to consider when buying a Kiln

by Ceramicsby Jas August 23, 2024

A few weeks ago, I sent an email discussing the best time to purchase a kiln. Since then, I've received many questions about what type of kiln to buy. I wish I could provide a simple, straightforward answer, but there are many factors to consider when choosing a kiln. To help you in the buying process, I've outlined these considerations below. Please note that I'll be focusing on electric kilns, as they are the most accessible and user-friendly.

1. Size and Capacity

Kiln Size: When selecting a kiln, it's important to consider the size and volume of the pieces you plan to create. Think about both your current projects and any potential future projects that might require larger pieces.The kiln should be large enough to accommodate multiple items in a single firing, which can help save time and energy. Be sure to check the internal dimensions of the kiln as well, including the maximum height, width, and depth, to ensure it can comfortably fit the pieces you typically make. For example, if you create small jewelry pieces, a smaller kiln may be sufficient. However, if you produce large platters, you'll need a kiln with a larger interior diameter to accommodate them.
Space Requirements: Before purchasing a kiln, thoroughly assess the available space in your studio or workshop. Kilns require adequate clearance on all sides for safety and ventilation. Check the manufacturer's recommendations for the required distances from walls, ceilings, and other equipment. Additionally, consider the space needed for the kiln lid or door to open fully without obstruction. Proper ventilation is also critical, as kilns emit fumes and heat during firing. Finally, ensure there is enough room for safe and easy access to the kiln for loading, unloading, and maintenance. This includes having enough space to move around the kiln comfortably and safely handle your ceramic pieces.

2. Temperature Range

Maximum Temperature: The maximum temperature a kiln can reach is a crucial factor to consider, as it directly impacts the types of clay and glazes you can use. Different types of clays/ glazes require different firing temperatures to vitrify. For example:
Earthenware: Typically fired at lower temperatures, around 900 to 1,150°C (1,700 to 2,100°F).
Stoneware: Requires higher firing temperatures, generally between 1,200 to 1,300°C (2,192 to 2,372°F), to achieve its strength and durability.

When selecting a kiln, ensure it can comfortably reach the maximum temperature required for your chosen clays and glazes. Although I typically fire my kiln to a maximum temperature of 1250°C, my kiln has the capability to reach up to 1300°C. This is preferable to having a kiln with a maximum firing temperature of 1250°C, since I don't want to push my kiln to its maximum firing capacity every time I use it.

3. Control Systems

Manual Controllers: Manual controllers require hands-on management throughout the firing process. These controllers typically consist of simple switches or dials that control the kiln's heating elements. With manual controllers, the user must manually adjust the power levels at different stages of the firing. This method requires a deep understanding of the firing process and careful attention to timing, as you need to be present to make adjustments at the appropriate times. While manual controllers can offer a high level of control and customization, they can also be labor-intensive and less precise than digital options. They are best suited for experienced potters who prefer a more hands-on approach and have the knowledge to manage the firing schedule effectively.
Digital Controllers: Digital controllers provide a more automated and user-friendly approach to kiln operation. These controllers use electronic interfaces to program and control the kiln's firing schedule. With digital controllers, you can set specific temperatures, hold times, and ramp rates (the speed at which the kiln heats up or cools down). Once programmed, the kiln follows the set schedule automatically, allowing for consistent and repeatable firing results. Digital controllers are particularly beneficial for potters who want precision and ease of use, as they eliminate the need for constant monitoring and manual adjustments. They also often include safety features such as automatic shut-off in case of over-temperature or power failure, making them a reliable choice for both beginners and experienced potters.

4. Power Requirements

Electrical Specifications: When purchasing a kiln, it is crucial to ensure that your studio has the appropriate electrical setup to support it. Kilns can vary significantly in their electrical requirements depending on their size, type, and features. Key electrical specifications to consider include:

Voltage: Kilns are typically designed to operate at specific voltages, such as 120V, 208V, 240V, or 480V. Most smaller, hobbyist kilns can run on standard household voltage (120V in the United States), but larger kilns often require higher voltages (such as 240V or 208V three-phase) for efficient operation. Higher voltage kilns can reach higher temperatures more quickly and are more energy-efficient.
Amperage: The current draw of a kiln, measured in amperes (amps), indicates how much electrical current the kiln requires during operation. It's essential to check the amperage rating of the kiln and ensure that your studio's electrical system can supply sufficient current. Larger kilns with higher amperage ratings may require dedicated circuits to prevent overloading the electrical system.

Wiring and Outlets: Depending on the kiln's specifications, you may need special wiring or outlets to safely operate it. This is particularly true for larger kilns or those requiring higher voltages. Consider the following:

Dedicated Circuits: Many kilns require a dedicated circuit, meaning the kiln should be the only device drawing power from that circuit. This helps prevent electrical overloads and ensures that the kiln operates safely and efficiently.
Outlet Types: The type of outlet needed will depend on the kiln's plug configuration. Larger kilns may require specialized outlets that are not standard in most homes or studios. Ensure that the appropriate outlet type is installed in your studio before the kiln arrives.

Before purchasing a kiln, consult with an electrician to verify that your studio's electrical infrastructure can safely accommodate the kiln's requirements. An electrician can help you determine whether any upgrades or modifications to your electrical system are necessary.

5. Budget and Cost

Initial Cost: The initial cost of a kiln can vary significantly based on several factors, including its type, size, features, and brand. Here are some key considerations:

Type of Kiln: Different types of kilns, such as electric, gas, or wood-fired, have varying price ranges. Electric kilns are generally more affordable and widely available, making them popular for hobbyists and small studios.
Size and Capacity: Larger kilns with higher capacity typically cost more than smaller, compact models. The size of the kiln you need will depend on the scale of your work and the volume of production. For example, a small tabletop kiln might be sufficient for a hobbyist making jewelry or small figurines, while a professional potter producing large sculptures or high volumes of pottery would require a larger, more robust kiln.
Features and Technology: The presence of advanced features, such as digital controllers, programmable firing schedules, safety shut-off switches, and sophisticated insulation materials, can increase the cost of a kiln. While these features add to the initial expense, they can provide greater convenience, precision, and safety, which may justify the higher price.

Operating Costs: Beyond the initial purchase price, it's important to consider the ongoing expenses associated with owning and operating a kiln. These costs include:

Energy Consumption: The cost of electricity is a significant factor in the total cost of kiln operation. Electric kilns consume a considerable amount of electricity, especially if they are used frequently or for long firing cycles. The cost of electricity can vary based on your location and usage patterns.
Maintenance: Regular maintenance is essential to ensure the kiln operates efficiently and safely. Maintenance costs can include replacing heating elements, repairing or replacing insulation, and servicing the digital controller or other electronic components. Regular cleaning and inspection of the kiln are also necessary to prevent buildup of debris and ensure proper functioning.
Replacement Parts: Over time, some kiln components may wear out and need replacement. This can include thermocouples (temperature sensors), kiln shelves and posts. The cost of replacement parts can add up, especially if you have a large or frequently used kiln. It's important to factor in the availability and cost of these parts when budgeting for kiln ownership.

6. Energy Efficiency

The quality of a kiln's insulation plays a critical role in its energy efficiency. Good insulation helps to maintain consistent temperatures inside the kiln by minimizing heat loss. This means the kiln does not have to work as hard to maintain the desired temperature, resulting in less energy being consumed. Insulation materials like ceramic fiber or high-grade firebrick are commonly used in kiln construction due to their excellent heat retention properties.

Electric kilns are generally straightforward to use and maintain. However, they can consume a considerable amount of electricity, especially for larger models or those that reach higher temperatures. When selecting an electric kiln, look for models with energy-saving features, such as programmable digital controllers that allow precise control over firing schedules and energy use.

7. Brand Reputation and Support

The quality, durability, and reliability of the kiln can vary significantly between brands, so it's important to choose a reputable manufacturer known for producing high-quality equipment. Here are some aspects to consider:

Reliability and Quality: Research brands with a history of producing reliable and well-constructed kilns. Reputable manufacturers typically use high-quality materials and components, resulting in kilns that are durable and have a longer lifespan. Look for reviews and testimonials from other ceramic artists, studios, and pottery schools to gauge the experiences of others with specific brands and models.
Customer Support: Having access to reliable customer support and service options is essential for addressing any issues that may arise with your kiln. When evaluating a brand, consider technical support, warranty, servicing and repairs, etc.

Take the time to carefully evaluate these factors to choose a kiln that best suits your creative needs, studio space, and budget.

I have two electric kilns from Nabertherm, top loading with capacities of 45 liters and 190 liters. I chose Nabertherm because it was the only brand available to me with a short delivery timeline (1 month as compared to 3 months from another brand). My experience with them has been very positive so far. There are several reputable commercial kiln brands, such as L&L Kilns and Skutt Kilns. I recommend choosing a brand that is easily accessible and offers reliable technical support and service.

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