An 11" by 17" Kiln Cautions Poster is available for download. This has an abbreviated list of important kiln cautions that you can display in your studio. Be sure to read through the entire list of cautions here or in your instruction manual.

Click here to download the Cautions Poster

1. All cautions and requirements recommended by L&L Kiln Mfg. Inc. are intended to help users operate their kilns safely and effectively. Many of these cautions apply to kilns and ceramic processes in general.
2. By using and/or downloading from this website, the user acknowledges that improperly installed, maintained, or operated process and manufacturing systems can pose serious and dangerous threats to worker safety, environmental integrity, and product/process quality.
3. Kilns operate at high temperatures and use high voltages/amperages. If improperly installed, maintained, or used, they can cause severe personal or property damage.
4. Commercial kilns come with various safety, performance, and operating limits, designs, and devices. If these are disconnected, altered, tampered with, or changed by the user, the user's employees, agents, or others acting on the user's behalf or with the user's knowledge, the risk and responsibility become solely the user's.
5. The user is also responsible for assigning properly trained personnel who have demonstrated common sense and general aptitude for such work to operate the kilns.
6. It is the user's sole responsibility to understand and ensure adherence to all safety notices and installation, operating, and maintenance instructions provided by this website and/or the kiln manufacturer.

1. Thermocouples (in automatic kilns) must be inserted into the kiln at least 1" (2.5 cm) in from the inside surface of the kiln.
2. They must protrude into the kiln itself because if the measuring tip of the thermocouple is buried inside the insulation the thermocouple will measure a lower temperature than the actual temperature in the kiln.
3. This could cause an overfire of the kiln.
4. Replace thermocouples once they are no longer reasonably accurate.

1. Do not use kiln without the supplied stand.
2. Never set a kiln on a floor without significant air space circulating under the kiln.
3. L&L stands typically raise the floor of the kiln by 8" (20 cm)  - except for the Plug-n-Fire which is 5" (13 cm)
4. See this link about installing kiln on a wood floor.

1. Make certain floor is not flammable. 
2. Install kiln so that the hot surface of the kiln is no closer than 12" (30 cm) to any wall. 18" (46 cm) is preferable.
3. Be careful about enclosed spaces: In general, it is not a good idea to install a kiln in a small confined space (such as a closet).
4. Maintain a minimum of 36" (91 cm) between the hot surfaces of two adjacent kilns, especially if they are going to be used at the same time. (The kilns will heat each other).
5. The essential issue with kiln clearance is to keep excessive heat from flammable surfaces. Remember, even when you follow clearance and ventilation recommendations, the kiln is giving off heat. Try not to locate it near things that can be affected by elevated temperatures. An example of this would be an electrical fuse panel which you do not want to overheat.

1. Rout Power Cord (or electrical connection wires) away from kiln in such a way that it can not touch the hot case of the kiln.
2. Secure it so it can not move.
3. If cord touches the hot case it could melt and cause a short circuit and/or fire.

1. Never use an extension cord with your kiln.
2. Locate the outlet close enough to the kiln to plug directly into it with its supplied power cord.
3. Kilns that pull over 48 amps and some three-phase kilns generally do not have a power cord. They need to be directly wired to the power supply.
4. You can directly wire any kiln without voiding the warranty or affecting the MET rating. Use 105-degree C wire for direct hookup.

1. The kiln must be kept dry.
2. It is best to keep it in an enclosed room away from inclement weather. See specific details in the INSTALLATION INSTRUCTIONS.
3. Note that our warranty does not cover damage from corrosion and electrical damage caused by inclement weather.
4. Water in contact with a kiln can cause an electrocution hazard.
5. If you keep a kiln outside (even in a very dry environment) and cover it with a tarp to protect it from rain you could still cause corrosion from the dew that forms on the cold metal surface of the kiln in the morning.

1. Check temperatures around the kiln when it is at high fire to be sure that you are not creating an unsafe condition.
2. Combustible surfaces that stay below 71°C (160°F) are generally considered safe from the point of view of starting a fire.

1. Keep an adequate fire extinguisher near the kiln and check it on a regular basis.
2. You may want to check with your local fire authorities to see if there are any specific requirements they have such as sprinkler systems, automatic foam extinguishers, etc.
3. Use a fire extinguisher that is rated for electrical fires (we recommend ABC rating).

1.  The kiln should operate in an environment that is between -18°C (0°F ) and 38°C (100°F).
2. Note that the control, if set up for degrees centigrade, may give you an error code if room temperature drops below 0°C (32°F). The DynaTrol and most other controls do not handle negative numbers.

1. Do not put sealed containers or combustible materials such as solvents, paper, rags, in or near kiln.
2. The kiln elements, when hot, could act as ignitor of flammable fumes. 
3. An explosion or fire could result.

1. Kilns generate harmful fumes when firing ceramics.
2. Fumes include carbon monoxide, sulfur oxides, hydrogen fluoride and metal vapors (all of which can be very toxic).
3. Install kiln in well-ventilated area.
4. Never operate in an enclosed space such as a closet unless you have good ventilation.
5. Aside from issues of ventilating the fumes from the firing, the heat build up in an enclosed room could present a significant fire hazard. See the INSTALLATION cautions.
6. Severe corrosion can be caused by kiln fumes, salt air or other environmental conditions.
7. Good venting can minimize these problems.
8. Ventilation must be to the outside.
9. Be careful not to locate the outlet of the vent near an open window (so that it could get sucked back into the building).

Helpful Tips

• What should I do to ventilate my kiln?
• See this for helpful tips on how to ventilate.
• See this for how to calculate ventilation requirements.
• Where should I put my kiln?
• Corrosion and ventilation
• If you are using a hood type vent (like the Vent-a-Kiln) do you need a kiln vent (like the Vent-Sure) also?

1. When working around a hot kiln be careful of the kinds of clothes you are wearing.
2. Some clothes could potentially catch on fire if they touch the hot surface of a kiln.
3. Also avoid loose fitting clothes that could catch on the kiln.

1. Clay contains silica dust which can be harmful (see silica caution) and that many glazes contain heavy metals such as lead, cadmium and copper.
2. While this caution is outside the scope of kiln safety it is worth mentioning here.
3. Keep your room clean and your kiln clean.

1. Kiln surface can be extremely hot: up to 260°C (500°F).
2. You can be severely burned if you touch the hot surface.
3. Display a sign near the kiln that specifically warns everyone of how hot the kiln is.

1. Protect any children, animals, and unqualified adults (anyone who is not able to understand these cautions) that may be near the kiln.
2. Aside from fumes that must be ventilated, and flammability concerns, they must be protected from the heat of the kiln and the electrical dangers.
3. Ideally, the kiln should be secured in a space away from any children (especially in a schoolroom situation where children might not always follow safety precautions).

1. Long term exposure to silica dust could cause lung damage.
2. See the Material Safety Data sheets from your supplier.
3. Exercise proper caution when mixing the dry powder and when removing it from your shelves.
4. Use a NIOSH approved particulate respirator for dust and use proper ventilation. You can buy these from safety supply houses. (NIOSH_approval #TC-21C-132 is an example).

1. Do not use silica sand in the kiln.
2. Some people like to use this as a work support medium.
3. The silica sand will attack the elements and thermocouples.
4. It can migrate in the kiln from expansion and movement due to heat.
5. If you must use sand to support or stabilize your load try alumina oxide or zirconia oxide sand.

1. Make sure the floor of the kiln and the tops of the shelves are coated with kiln wash.
2. This will protect these surfaces from melting glaze and ceramics.
3. Do not coat the undersides or sides of the shelves.
4. Do not apply kiln wash to the brick sides or element holders. (Damage to the elements could result).
5. If you have a kiln sitter, put kiln wash on the cone supports (not the sensing rod) for accurate cone action.
6. Clean off the old wash and reapply new wash each time you fire or when it begins to chip away.

NOTE: L&L does not supply kiln wash. contact your local ceramic dealer.

1. Never load moist greenware or pots in your kiln.
2. The expanding water vapor in the ware could cause the ware to explode, damaging your kiln interior.
3. We recommend using a dry out segment in your bisque program at 66°C (150°F). (Note that, because of the thermocouple offset programmed into our DynaTrol when we use the ceramic protection tubes, the display temperature will read 93°C (200°F) when the real temperature is 66°C (150°F)).
4. Remember that there may be water trapped in the work even if you can't always see it. If you place a piece of greenware next to your wrist and it feels cool to the touch it probably has too much moisture in it to fire.

1. Plastics, organic materials, bakeable modeling clay, mothballs and a large variety of materials can decompose under heat causing the release of highly toxic fumes or rapid uncontrollable combustion.
2. Rocks, marbles, cement and other materials may explode under high temperatures.
3. Before firing anything but ceramics, glass and metal (obtained from a known reputable source) in a kiln carefully investigate what happens under heat.
4. This is the sole responsibility of the user.
5. The kiln is not designed to be used for firing hazardous materials.
6. Adding propane, wood, charcoal or other materials intended to produce a reduction atmosphere can be hazardous if the volume is sufficient. Note that these materials can cause an explosion under certain conditions (just the right amount of air and flammable gasses at just the right temperature) which could cause injury or death. Moreover, a reducing atmosphere can cause premature element failure by reducing the protective oxide coating on the elements. Also note that carbonaceous materials will produce poisonous carbon monoxide and highly flammable hydrogen as they decompose at high temperatures. Also note that the "auto-ignition" temperature of flammable gasses is generally above 1400° F.

1. Tempered glass can explode when fired.

1. When you heat wax (in wax resist and lost wax processes) it will volatilize and potentially condense in the cooler ventilation ducts.
2. Over time this can cause a fire hazard because the wax is flammable.
3. Depending on how the vent motor is mounted, the wax can also gum up the vent motor.
4. If you use these processes it is entirely up to you to engineer and monitor the safety of the installation.
5. The use of wax will void the warranty of the vent system.

1. Use dark glasses (shade number 1.7 to 3.0) to view inside the kiln through the peepholes or door opening when firing. These will protect you and your eyes from radiant infrared radiation in case the ceramic ware explodes. Do not use regular sunglasses for this—they are not designed to protect your eyes from this type of radiation.
2. Use heat-resistant gloves when opening peephole plugs or the door. The peephole plugs or door are very hot and can burn you.
3. Do not open the kiln lid unless the kiln is turned off (except for carefully controlled troubleshooting tests). There is danger from electrocution. Cracks caused by propping open the lid are not covered by the warranty.
4. Use heat-resistant gloves when opening a hot lid.
5. Do not open the lid when the kiln exceeds 121°C (250°F).

1. Keep lid closed when not operating the kiln.
2. Otherwise the weight of the lid over time may force the hinge and stainless wrap to move down.
3. This will affect the way the lid closes and may cause the lid to crack.
4. It will also keep the kiln cleaner by keeping dust out.
5. In addition, if the kiln somehow gets turned on accidentally, an open kiln could present a fire hazard.

1. Do not use the lid as a storage shelf.
2. The lid could crack.
3. Also - this practice could lead to a fire if you accidentally leave combustible materials on the lid.

1. Turn off power to the kiln when loading or servicing.
2. If power is on when you are loading or unloading the kiln it is possible to touch the elements and get electrocuted.
3. We recommend having the kiln attached to a fused disconnect switch with a lockout device (in any institutional or industrial installations where someone could turn on the kiln while someone else was working on it).

1. You may burn yourself.
2. You may harm your work.

1. Stilt marks and other sharp protrusions can cut you.
2. Remember that that glaze is like glass.
3. Wear safety glasses while grinding or knocking of stilt marks.
4. Check the shelves for broken bits of glaze which may have attached to the shelves. These can be like shards of glass that can cause a serious cut.

1. We recommend attending the kiln while firing.
2. NO AUTOMATIC SAFETY DEVICE IS FOOLPROOF! BE ESPECIALLY CAREFUL ABOUT ATTENDING THE KILN WHILE IT IS SUPPOSED TO SHUT OFF. (The Delay feature in automatic kilns gives you control over this).
3. The controller is used to control temperature; it is not a safety device.
4. If you have a manual kiln with a Kiln Sitter PLEASE BE EXTRA CAREFUL! Kiln sitters can be very unreliable because of the moving parts, dirt or clay that can get into the tube, the way cones are placed on the tube, corrosion, etc. DO NOT FIRE THIS KILN UNATTENDED WHEN THE KILN IS SUPPOSED TO TURN OFF AND LEARN HOW TO USE THE TIMER BACK UP. Neither L&L Kiln Mfg., Inc. nor Edward Orton Jr. Ceramic Foundation warranty the kiln or kiln sitter against damage caused by overfiring. ALMOST ALL OVERFIRED KILNS WE SEE ARE FROM A MALFUNCTION OF A KILN SITTER. We highly recommend firing all manual kilns with witness cones that you can see through the peephole and/or a pyrometer so you have some idea of what is happening inside the kiln.

1. Become familiar with either the control (if you have an automatic kiln) or the Kiln Sitter (if you have a manual control or have that as your backup control).
2. Do this before operating the kiln.

1. Check element holders and walls for glaze, clay chips or anything that could melt at a high temperature.
2. If melted clay or glaze comes in contact with an element, a rapid failure could result. The molten material traps the heat radiating from the element and subsequently raises the surface temperature of the wire. The temperature will quickly pass the maximum recommended temperature for the wire and burn it through it.
3. To clean holders, a good shop vacuum will handle dust and loose crumbs. A very gentle chisel or grinder may help with glaze contamination on element holders, but remember that the elements themselves are quite brittle when they are cool.
4. Replace the contaminated holder if you can not clean it.
5. Remove any glaze that has splattered on the firebrick or shelves. (USE SAFETY GLASSES WHEN DOING THIS BECAUSE GLAZE CAN BE LIKE BROKEN GLASS). Vacuum afterward. Note about vacuuming: it is possible to build up a strong static electricity charge when you are vacuuming. If this somehow manages to discharge into the control it can ruin the electronic circuit. Make sure vacuum is grounded and periodically touch some grounded metal surface away from the kiln to discharge the energy.

1. Shut off kiln when servicing it unless you are doing a live test that specifically calls for power. If you are in an institutional or commercial setting use a lock out/tag out procedure. Unplug if the kiln includes a plug; if not then turn off at the closest circuit breaker or fused disconnect.
2. When testing ohms for an element circuit you do not need the kiln powered.
3. The elements carry high voltage and can electrocute you. Many of the tests described in the troubleshooting manual are performed under power. They should be done ONLY by someone who is familiar with electrical safety such as an electrician or trained maintenance person.
4. As long as the kiln is unplugged or turned off at the fused disconnect switch or circuit breaker (and checked with a reliable meter to be sure) you are safe.

READ THE FULL CAUTION ABOUT ELECTRICAL SAFETY

1. Check wires for deterioration or oxidation.
2. Replace any that seem brittle or where the wire insulation has deteriorated or fallen off.
3. Check terminals for oxidation (discoloration).
4. If you are near salt air or if you notice corrosion on the stainless exterior of the kiln for whatever reason (like certain fumes generated by your work) then do this far more frequently.
5. Check power connection terminals in the kiln and control box for tightness. Be sure to do this with the power disconnected (unplugged) for the kiln. If these terminal connections get loose heat can be generated (because the electrical resistance gets greater) and this can cause a fire.
6. Check thermocouple connections for corrosion, tightness and oxidation as well. A bad thermocouple connection can change the accuracy of the temperature reading which could cause an overfiring.

1. Occasionally check temperatures of the main power cord at the main receptacle and the main kiln breaker while the kiln is at its hottest.
2. If these are hotter than normal, it could be a sign of a loose or corroded connection, or possibly the wire gauge used in the power hook-up is the wrong size for the amount of current being drawn by the kiln.
3. Immediately diagnose and fix this because it could cause a fire.
4. Also check temperature of any other cords on the kilns (such as element jumper cords).

1. When replacing infinite zone switches (and other electrical components), replace the electrical connectors.
2. At the very least check for discoloration (an indication of oxidation).
3. Electrical connectors will typically oxidize over time where there is heat and this can cause further overheating of the part at the connection point. This can in turn lead to early failure of the part, wire and connector.
4. Make certain that the new connectors are firmly crimped onto the wire.

1. Non-L&L elements can present a potential hazard to the kiln or cause a fire (by drawing too much amperage).
2. The wrong type of fuse, relay, switch or other component can cause a fire or other hazardous condition.
3. An improperly rated cord can cause a fire. 

1. We do not recommend any coatings for the elements.
2. Use of ceramic coatings will void the warranty on the elements and potentially the firebrick or element holders if it contaminates them.
3. We have not adequately tested these coatings so we can only say, at this time, that any trouble that results from the use of ITC and other coatings must be at the risk of the user.
4. We do use a proprietary coating on all our firebrick that improves firebrick life and reduces dusting.

1. All customer modification is made solely at the risk of the customer.
2. Modifications will void the warranty.
3. L&L takes no responsibility for hazardous conditions created by unauthorized modifications.
4. Any authorization for an engineering change must be in writing from the factory.