FrogBlog
Understanding Kiln Relays: For New Kiln Buyers and Owners
Ah, the timeless query of kiln shopping: "Which kiln relays should I go for?" It's like asking a chef for their salt preference – important, but let's not get too salty about it. Kiln relays are like the Elon Musk of the kiln world – well-known but often misunderstood. If you're scratching your head wondering about relays, don't fret. This article will shed light on the topic, enlighten you, and make you wonder how you ever survived without this knowledge. Your kiln's relays are the VIPs of the whole kiln operation. Treat them right, and they'll keep your artistic dreams alive. Neglect them, and you'll end up with a sad, cold kiln. So, let's grasp the basics of relays, so we can discuss relay care and maintenance. What are kiln relays, and how do they work? A kiln relay functions as a gatekeeper, regulating the electric current in a kiln. When a relay is closed, it allows energy to flow to the kiln's heating elements, making them hotter. Conversely, when the relay is open, the circuit is interrupted, and no electricity reaches the coils, resulting in no heat. Larger kilns are equipped with multiple relays, each controlling a specific area. Imagine relays as bouncers at a nightclub. They ensure things don't get too hot with an overcrowded club. They let in just enough people to heat up the action, then close the door to maintain the perfect temperature. When things cool down, the relay receives the signal to allow more people onto the dance floor (the element), restarting the cycle. That clicking sound your kiln makes during firing? It's the mechanical relays cycling on and off, akin to a bouncer opening and closing the club door to maintain the desired temperature. What are the different types of kiln relays, and how do they differ in function and longevity? Just imagine you're cruising down the highway, wind in your hair, not a care in the world because you never have to change your car's tires! No more struggling with lug nuts or getting your hands dirty. Ah, the relaxing feeling of never having to deal with a flat tire or the dreaded tire store. It's like winning the lottery, but without the money or the fame. Mercury and solid-state relays are kind of like that, they're the choose-it and forget-it component of your kiln that you'll never be sorry you chose. Mechanical relays are like the candles on a birthday cake - they have a limited lifespan and eventually need to be replaced. They'll last you about as long as a Kardashian marriage, so make sure to cherish every click. There are three main types of kiln relays: 1. Mercury relays: These use a tube of mercury with an internal weight that determines whether the mercury rises to complete the electrical contact. With fewer moving parts, mercury relays have an impressively long functional life, typically lasting around 5 million cycles. They are nearly indestructible, but due to mercury disposal concerns, some states no longer allow their use. 2. Solid-State relays: Operating with power semiconductor devices, solid-state relays have no moving parts. They control the flow of electricity by opening and closing. Due to their lack of moving parts, these relays boast an exceptionally long functional life, said to surpass 1000 years! They offer tighter temperature controls because they cycle faster, which is also said to save energy. 3. Mechanical relays: These relays utilize electric current to move a contact, either opening or closing the circuit using an electromagnetic switch. Mechanical relays do have moving parts and because of that they have a limited lifespan. On average, they last around 200,000 cycles (clicks), which translates to approximately 18-36 months, depending on usage, firing temperatures, and schedules. Why is it crucial to monitor the health of kiln relays? Imagine if your trusty relay suddenly called it quits. It's either going to be a hot mess or a complete blackout. If the relay stays open, you'll be left with a cold and useless kiln – no heat for you! On the other hand, if it fails in the closed position, get ready for an intense blast of unending heat. Neglecting to monitor your mechanical relays can turn your project into a disaster, leading to kiln meltdowns or accidental kiln damage. While larger kilns with multiple relays offer some backup, you'll still sense that something has gone awry. When should you replace your kiln Relays? Now, let's address the million-dollar question: When should you replace your kiln relays? Well, imagine your relays belting out Whitney Houston's "I Will Always Love You." That's your cue to bid them farewell! The lifespan of your relays depends on their type. If you have mercury or solid-state relays, consider them ageless wonders that can last the entire lifespan of your kiln, just like Rob Lowe's ever-youthful career or the timeless elegance of Jane Fonda, or even Cher. They just don't age! A periodic visual inspection should suffice to ensure their good health. However, if you're rocking a mechanical kiln relay, it's a different story. These relays have moving parts, which means they eventually wear out like a neglected houseplant. On average, you can expect them to last around 18 to 36 months. Of course, usage, firing temperatures, and firing schedules play a role, so it's best to replace them every 18-24 months as a precautionary measure. Luckily, some kiln manufacturers have added nifty features to make relay monitoring easier. Jen-Ken Kilns has installed a "pilot light" on every relay of every model. It's like having your own personal relay detective! If the light stays dark when the relay fires, you know there's a problem with the element, relay, or connection. Evenheat Kilns introduced a relay access door, a secret passage to a world of wires and switches. It's a magical portal that saves your fingers from untangling wires like a hopeless spaghetti chef. When it's time to replace a relay: Be sure to check for heat damage on the old relay. Look for melted spots in the plastic body, indicating excessive heat. In such cases, replace the push-on terminal of the wire connected to the relay before installing the new one. Loose terminals can wreak havoc on the new relay, as they generate excessive heat and compromise performance. Remember, a well-maintained kiln with healthy relays will keep your creative projects on track. So, embrace the kiln relay journey, have some fun with it, and keep those artistic dreams alive. And hey, who knew kiln relays could be so entertaining? Now go forth and conquer the world of kiln-firing with your newfound relay knowledge! For more information on kiln relays and replacing them, check out these resources from our trusted manufacturers: Evenheat Kilns: Relay Replacement via Access Port Showcase Paragon Kilns: Relay Replacement Guide and YouTube video. Olympic Kilns: Relay Replacement Guide Jen-Ken Kilns: Small Relay and Large Relay So, there you have it! Kiln relays may seem like hidden heroes, but they play a vital role in the success of your creations. Understanding their purpose, types, and lifespan is key to maintaining a well-functioning kiln. Remember to regularly inspect your relays, replace them when necessary, and keep an eye out for any signs of heat damage. Now, armed with this newfound knowledge, you can confidently embark on your kiln-firing adventures. Whether you're a seasoned artist or just starting out, the dance between you and your kiln relays will be one of artistry, precision, and, most importantly, creativity. So, turn up the heat, let the kiln roar, and let your imagination run wild as you create beautiful ceramic pieces with the assistance of your trusty kiln relays. Happy firing! Need to order replacement relays? This form can help!Or if you know what you need, here is a link to order mechanical relays If you have any more questions or need further assistance, feel free to ask. You can talk to a real person on the phone immediately (361-596-3764), or via instant chat (click here to start a chat now), email (customerservice@kilnfrog.com) or via real time texting (361-596-3764) - you choose! (We promise we will respond during regular business hours.) Enjoy your artistic journey!
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Troubleshooting Your Controller
From electrical power issues to temperature, display, and keypad problems, Paragon Kilns has designed a Troubleshooting Guide for the Sentry Controller. Even though it was created by Paragon for the Sentry 2.0, this guide can help with almost any digital controller as the basic principles are the same. With of all the great insight included in the guide, my favorite part is how it describes the six basic parts a digital kiln uses to control heat. And, understanding how your kiln works will simplify all of your troubleshooting efforts!
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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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Why is my Kiln or Oven Not Heating Properly?
Let's be honest... using a kiln comes with its share of emotional ups and downs.
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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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Observing a Kiln During Firing... What's Normal?
A big thank you to our friend Arnold from Paragon Kilns who helped answer these important questions about observing your kiln during firing. Gail also added some nuggets of information to help round out your knowledge! The heating elements hum when they turn on. The sound is generated because the elements vibrate in the brick grooves due to magnetism between the coils. So, it's totally normal! The sound actually diminishes as the kiln gets hotter because the elements soften. Notes from Gail: This is also true in kilns with suspended quartz wrapped tubes, but it's harder to hear since the elements are inside the tubes. Elements that are wrapped around ceramic rods probably won't hum much at all. The clicking noise of an infinite switch-operated kiln is also normal. It is the sound of an infinite control switch cycling on and off. When the clicking turns into a popping noise, the switch is probably about to fail. Notes from Gail: This isn't happening if you only have a digital controller. But, some kilns have an infinite switch in the lid with a digital control of the body. You'll be hearing the clicking on those. Digital Relays are another source of clicking. To turn on the elements, a digital controller sends twelve volts to the relays. The relays, in turn, act as switches and send full voltage to the elements. The relays click every time they turn on. A chattering noise, however, indicates that a relay is about to fail. Notes from Gail: This is why I'm a big fan of MDRs (mercury displacement relays) and SSRs (solid state relays.) They are much quieter and worth the money to upgrade in the long run! A crackling noise followed by a loud POP from the kiln's switch box usually means that a loose electrical connection has just failed. If you hear crackling, which sounds like sparks, turn off the kiln. The loose connection creates a tiny electrical arc, which overheats and burns electrical parts. Rapid arcing causes the popping noise. Whenever you change elements or have the switch box open for any reason, check all of the wire connections. Make sure they are tight... The power must be disconnected, of course. Tug on the wires. If a wire pulls out of a terminal, replace the terminal with a new one using a good crimping tool. Remove any dust before closing the switch box. When you replace elements, make sure the connections are tight. Notes from Gail: This happens in clamshell kiln lids occasionally, since the lid is constantly being opened and closed, the element connections an get loose. Don't despair, it's an easy repair. Why is there a gap between the kiln and the lid near the hinge? The gap under the lid of a cold kiln at the hinge is normal. As the kiln heats up, the firebricks expand, which causes the body of the kiln to grow taller and close the gap. The gap is designed to help prevent the front of the lid from rising at high temperatures. Notes from Gail: Yup! The lid on my kiln is rising at the front during firing. What is the cause? During firing, the wall bricks expand. This pushes the lid upward. If the hinge does not have sufficient play, the lid will rise at the front. If this happens, please do not put a weight on the lid to hold it down. That will only damage the lid. Instead, check for binding in the hinge. Notes from Gail: If this is happening, call the kiln manufacturer and ask them how to mitigate the problem. They'll walk you through an easy fix for your type of kiln. If this becomes extreme, it can crack your kiln lid so, it's important to take care of this issue sooner rather than risk a messy, crumbling lid. My front-loading kiln has a gap between the door and the firing chamber. Is that normal? There should be no gap between the door and the firing chamber at the side toward the door latch. There should be a gap, however, at the hinge side of the door. When the kiln is cold, you should see a gap of about 1/16 between the hinge side of the door and the firing chamber. As the kiln heats, the firebricks expand. Without a gap, the door will bind at the hinge and cause a gap at the side toward the latch. Notes from Gail: Some kilns have gaskets that fill the space and seal the door opening. If you have a gasket that is worn, it's easy to get a replacement from the manufacturer and should help alleviate the issue. New doors can also be purchased if needed. I am concerned about the light that appears under my kiln lid during firing. The light that you see under the lid is normal as long as the lid is not rising in front. The inner lid surface expands more than the outer cooler surface. Therefore, it bows inward slightly toward the firing chamber. This is normal. For this reason, you will see a thin line of light around the lid since the lid is no longer a flat surface resting on the flat firing chamber sidewalls. Surprisingly, there is very little heat loss from around the edge of the lid. Notes from Gail: If you suspect this is causing a cold spot during firing, call your manufacturer. If this becomes a serious issue, you can purchase replacement lids at reasonable prices for most top loaders.
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When the Kiln Lid Flakes...
Great information about kiln lid repairs from our friends at Paragon... At Paragon, they coat the inner lid surface of all kilns to reduce brick dust. Sometimes the refractory coating is too thick so, it will blister and flake off when the kiln is fired. An especially thick coating looks like a network of peeling cracks similar to a dried mud puddle. This cracking is due to the difference in expansion between the firebricks and the coating. Conversely, correctly applied kiln coating will look like it disappeared after the kiln has been fired. The good news is that cracked lid coating is easy to repair. Just lightly remove the blistering coating with sandpaper and apply a new coat of liquid kiln repair cement. Keep in mind that the natural tendency is to apply too much lid coating because it just looks better than a thin layer. If done correctly, you should still be able to see the firebrick pores under the coating! First, shake the container very well! Then, pour some of the coating into a bowl. Make sure to stir it just before you apply it to the firebricks. Apply the coating with a large, soft sponge. Moisten the sponge with water; then squeeze out the excess... this is a very important step! Dip the sponge into the bowl of kiln coating. Wipe the coating over the lid surface. Do not let excess coating run into the element grooves of the kiln. Applying a light coat will prevent this from happening. If the coating drips along the edges of the grooves, remove by wiping a cotton swab or rag along the groove. Many people have asked us... "What is the difference between kiln cement and Liquid Kiln Coating? Can a lid be coated with a thin mixture of kiln cement?" The answer is YES! Kiln cement thinned with water will work as a lid coating. Liquid Kiln Coating is simply a mixture of kiln cement, fine brick dust, a gumming agent, and water. The great news is that lid coating lasts for several years. So, it's not something you need to worry about on a daily basis. But, if you start getting kiln brick dust on your work, maybe it's time to re-apply. Some kilns such as the Paragon CS-14S allow you to upgrade to a fiber top, which helps to keep your kiln cleaner and reduces the chance of debris in your pieces.
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