FrogBlog
The 10 Best Pottery & Glass Kilns for Beginners + What to Look For
If you're venturing into the world of pottery or glass artistry, having the right kiln is essential.
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The 7 Best Pottery & Ceramic Kilns for Home Use
In the world of pottery and ceramics, the kiln is an essential tool for firing clay creations to perfection. Whether you're a novice artist exploring your creative side or an experienced ceramicist honing your craft, having the right kiln can make all the difference in achieving the desired results.
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How Low Voltage Affects Firing Time
Knowledge is POWER! Making sure you have the correct voltage is one of the most important factors of kiln efficiency! Plug the kiln into the correct circuit. Low voltage can double the firing time. If your kiln is firing too slowly, make sure the voltage listed on the kiln’s electrical data plate matches the voltage of the electric circuit. The electrical data plate is usually located on the side of the kiln or the switch box. Firing a 240-volt kiln on 208 volts reduces the kiln’s power by 25%. Even a small drop in voltage can affect the firing speed. Low voltage has the same effect as firing with worn out elements. Even a small drop in voltage can slow down your kiln. For example, we test-fired a 120-volt kiln that took 5 hours and 3 minutes to reach 2331°F (1277°C). On a separate electric circuit, the same test kiln took only 2 hours and 30 minutes to reach 2350°F (1287°C). The difference in voltage between the two circuits? Only 7 volts. Fire the kiln when the voltage is highest. Turn off other large appliances. If your kiln ever slows down temporarily, do not assume that it is due to worn elements. The voltage to your building may have dropped due to peak demand. Have an electrician check the voltage under load while the kiln is firing. Until you know the voltage, an amp reading of the kiln won’t tell you much, because low voltage also causes low amperage. If the voltage is low during a period of peak demand, fire your kiln when the electrical demand is lower and the voltage is higher. Fire at night or early morning. Also, turn off other large electrical appliances such as a clothes dryer while the kiln is firing. Program at a slower rate. A digital controller will show error messages when it has been programmed at a faster rate than the kiln is capable of firing. This can happen even when the voltage is normal and the kiln is new. You may be using a firing schedule that is designed for a faster kiln. In this case, program at a slower rate. Moist clay can slow down the kiln. Another reason your kiln may be firing slowly is that the firing chamber has too much moisture. Firing moist ceramic greenware or moist glass molds can slow down the kiln. Dry these materials before firing them. Reduce the load density. Overloading a kiln with a dense load of ceramics and kiln furniture can also slow down the firing. Have the power company check the transformer. If the kiln still fires too slowly after following the suggestions above, have the power company check your voltage and readjust the transformer for your area if necessary. You can also request that your power company put a voltage recording unit at your location to check the voltage over an extended period.
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Kiln Q&A
Learning from others is at the heart of the kiln community. So, I thought everyone would enjoy some Q&A as we just love to share knowledge and information! When using or buying a kiln... this extra insight not only saves you time but, often money, too! Can a small test kiln accurately duplicate the firing of my larger pottery kiln? A digital controller on a test kiln can duplicate the firing of a large kiln. Find a test kiln that has a simple 3-key controller. It won't have all the features of the more expensive 12-key controller, nevertheless, it can slow the cooling to whatever speed you want. Keep in mind that most 120-volt kilns are rated to 2000 F so, make sure you use one that is rated to 2300 F. Examples for great small test kilns are the Paragon Caldera Digital and the Olympic HB86E. I need a small kiln that can be moved often. What do you recommend? Since you are going to move the kiln frequently, we would suggest a fiber kiln. They are lighter than firebrick kilns. However, you can move a small, tabletop firebrick kiln without damaging it, you just need to be extra careful. Whether you get a fiber or firebrick kiln, its a good idea to save the carton and foam packing from the original shipment. The packing is designed to protect the kiln. Also, be sure to place a sheet of foam packing material between the kiln body and door or lid whenever you move a kiln for extra security. Is there a reason to buy a ceramic shelf instead of a fiber shelf? A ceramic shelf is recommended for activities like pattern bars, pot melts, high fires, or any there techniques that requires temp to be held at 1450F or above. A fiber shelf will be marred by these activities and won't stay smooth as the glass moves. Can a kiln be safely operated on a wooden work table? Yes, but it's not ideal! You will need a liner to buffer the heat. We recommend a concrete board, i.e. hardy-backer or Duraboard, or at the minimum, a double layer of ceramic tiles. It is easy to find at your local hardware store, and it's fireproof so it will protect the table and the area. Metal is always the preferred surface for a kiln table or cart. I'm curious how hot a fiber kiln gets on the outside vs. a conventional kiln? A fiber kiln reflects heat internally and a brick kiln absorbs the heat, so a fiber kiln will not be as hot on the outside. With that said, at a full fuse (1480F) the kiln might be 200-300F degrees on the outside. Is it worth the extra cost for a solid state or mercury relay on a new kiln? Glass fusing kilns are much harder on relays than ceramic kilns because of the very long glass annealing times that are typical with glass. (The glass is cooled slowly during annealing.) The same holds true for heat treating, crystalline glazes, bead annealing or any kiln that is holding temp for a long period. With that in mind, we think the optional mercury relay or solid state relays are well worth the money. They cut down on maintenance and help you elements last longer too! How much heat is lost through a kiln’s bead doors when mandrels are inside? With bead mandrels extending out past the bead door of a kiln, there is some loss of heat, but it is minor. In our opinion, not enough to make a difference. The kiln's digital controller and thermocouple will sense any differential and accommodate for this by firing the elements when needed to make up for any heat loss. Do I need a top load or a front load glass kiln? Top load kilns offer the most size for the cost. They can fire most glass projects but they are not good for projects that require manipulating the glass during the firing as the artist is subjected directly to the heat when the lid is opened nor are they recommended for bead annealing. Front load kilns are better for bead annealing and manipulating glass during the firing. They are also easier to load with large glass projects on the kilns shelves. What type of kiln is best for copper enameling? Copper enameling is best done in a front-loading kiln. This is because the copper pieces are removed while red-hot. When you open the door of a front-loading kiln and remove the piece with an enameling fork, you are comfortably out of the way of the rising heat. Removing an enameled piece from a top-loading kiln is more awkward and can be dangerous. Before opening the kiln to remove the piece, always turn off the power to the elements, which may mean turning the kiln off if your kiln did not come with a power interrupt switch. To enamel another piece, you can turn the power back on after you have closed the kiln door. To check out an example take a look at the Paragon SC2. How is depth measured in a kiln? The interior depth is always front-to-back for a kiln with a door and top-to-bottom for a kiln with a lid. For outside kiln dimensions, depth is the distance from the front to the back. For glass, do I need elements in the top and sides or only the top? Glass does not like temperature variation. Though top elements offer even heating across a flat piece of glass, top and sidewall elements are recommended for firing tall or deep pieces with molds. Side elements offer more even heating of the sides of drape molds or deep castings. Basically, the deeper you want to slump, the more side elements become necessary. How do I get a wide ceramic kiln through a 32” doorway? Many top-loading ceramic kilns are sectional. You can disassemble them and carry the sections through narrow doorways or downstairs. It can take some time for a beginner to disassemble and reassemble a sectional kiln. If the kiln is front-loading, you can temporarily remove the door handle and the back element cover. If necessary, you could also remove the door itself. Please have a kiln technician remove and reinstall the door for you if you do not feel comfortable with the project. An example of a kiln that is structured in sections is the Olympic 2827HE. Have more questions? Call us... as always, we are happy to help!
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The Fear of Buying your First Kiln
Don't sweat it! We've got you covered.From glass to pottery, heat treating to annealing... we have handled thousands of questions that revolve around buying your first kiln. So, we thought we would share our favorite nuggets of advice from some of our most frequent questions.Q1: I am considering buying my first kiln. The choices and information seem overwhelming as they all look so similar. How do I know which one is right for me?It can be an instant information overload. We think that choosing a kiln becomes simpler when you narrow the search with these factors: The size of the electric circuit in your studio... your kiln choice will be limited by the number of amps available. The size of the kiln... estimate how much firing chamber space you need. For glass and clay, you may also want to consider the shelf size, too! Front loading or top loading, a choice with real consequences for ergonomics, capacity, and price. Max firing temperature. After you reduced the kiln selection search with those four factors and make a list of models that you are considering. Then, compare those kilns and manufacturers in greater detail. This process will make everything better, promise!Q2: I’m nervous about ordering my first kiln... and, have so many questions. Do you have any pointers that will help? We totally understand that ordering a kiln can be complicated. But, it doesn’t have to be. Here is a great checklist to help you avoid any issues: Is your dealer knowledgeable about firing? This can be as important as the price of the kiln. What about warranty repair? Make sure you understand how the manufacturer handles the warranty. If comparison shopping, have you asked about the cost of crating or residential delivery? Are you paying extra for the stand as some are not included? Do you need to order a kiln shelf? Most kilns do not include them. Do you have a covered, well-ventilated location for the kiln, protected from the weather? Is the area free of flammable materials? If you are going to use the garage, plan on parking the car in the driveway during firing. Is the kiln room large enough? You will need 12" of additional clearance on all sides of the kiln during operation. We do not recommend small, enclosed rooms such as closets. Will the kiln fit through the doorway? Measure to be sure. Sounds crazy but, we know of cases where doorways had to be torn down to move the kiln into the firing room. Are you sure about voltage and electrical phase? 240 and 208-volt outlets cause confusion because they look the same. Check with your electrician, if in doubt. Ordering a kiln of the wrong voltage can be very difficult to remedy! Will you need special wiring? Figure this into your budget before ordering the kiln. Q3: How will putting a kiln in my garage affect my homeowner’s insurance? Our friends at Paragon shared this info regarding homeowner’s insurance: Some insurance companies simply don't insure kilns. No matter what you tell them, they won't change their minds. Other insurance companies need extra information--i.e., the kiln is UL Listed--before they will OK the kiln. If they need more information about safety, we will be glad to supply it from the manufacturer. Still, other insurance companies have no problem with kilns and don't even care if you have one. A properly installed and operated electric kiln is very safe. Do not leave it unattended during operation, and disconnect the power when not in use. Keep flammable materials out of the firing room. If you fire the kiln in a garage, remove cans of paint and gasoline. Store them in a separate building such as a garden shed. If you follow these basic rules and the others listed in the manual, your kiln will be a source of joy rather than of worry.As always, if you need help or have questions... call us! We are happy to help!
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What is the biggest kiln available on household current?
The number one piece of advise we give to someone looking to purchase their first kiln is... "purchase the biggest one you can afford". We say this, not because we are greedy but, because we all know that once you start... it's impossible stop! The creative juices start flowing and you just want more, more, more!!! The number one question we get in return is... 'What is the biggest kiln I can run on 120v household current?' In other words, what is the largest 120v kiln you can buy? That is a great question because the answer is not that easy. Before we get to the list, it's important to talk about power and performance. To provide the performance it was designed to give, a kiln must have the proper outlet and matching breaker to supply adequate voltage and amperage. An incorrect connection may cause disappointing or even hazardous results. Smaller kilns (under 13”) typically run on household 120 volt, 13 amp household current. This will allow the owner to plug the kiln into just about any plug in the house. Most standard household breakers are 15-20 amps, so a 13 amp draw on that breaker will not overtax or “blow” the breaker. When the firing chamber increases in size, the amperage required to heat the chamber will increase to 15-17 amps. These higher amperage requirements will dictate the need to install a dedicated circuit of 20 amps to be installed. This new circuit will be dedicated specifically to the kiln, and will not have anything else attached to it that will draw power. Most homes in the U.S. are wired with a combination of 15-amp and 20-amp, 120-volt circuits. Because 15-amp receptacles (5-15R) can be used with 20-amp circuits, most of the receptacles you see in homes are the standard 15-amp variety, with two slots and a U-shaped grounding hole. Twenty-amp receptacles (5-20R) have a horizontal slot branching off one of the vertical slots. Plugs designated as 20 amp will not fit into 15-amp outlets. If you have questions, we always recommend talking to a licensed electrician. Now that we got through all the technical talk, here is the full list of all 120v kilns: 5-15R KILNS Jen-Ken AF3P 15/6 Jen-Ken ProFusion Fiber 16 Paragon S1310 Trio Paragon FiberFuse 16 Paragon Fusion 7 Evenheat Studio Pro 14 Evenheat KH 414 Evenheat KH 418 5-20R KILNS Paragon Max 119 Paragon CS-16S Paragon Fusion 16 Paragon CS-16D Paragon KM14T Paragon KM18T Paragon PMT10 Olympic Quatro 16 Olympic Quatro 16 TLC Olympic 186GFE Olympic Square 186GFE Olympic Square 186GFETLC Evenheat Studio Pro 17 Evenheat HF 810 Evenheat RM II 810
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