Is your kiln performing as it should?
Paying attention to the maintenance of your kiln and keeping stock of spare parts is crucial for consistent firing results and extending the life of your equipment, saving you downtime.
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Before Every Firing:
Ensure your kiln is switched off and run your eyes over the inside.
Ensure there is no residue from the last fire. Inspect your elements to make sure no glaze or fragments have found their way onto the elements and kiln furniture, if so, carefully remove with a light vacuum or in the event of glaze a careful scrape with a knife making sure not to damage the elements or chip with kiln walls and thermocouple.
Kiln Furniture wash
This is also a good time to note if you need to re-apply kiln wash to your furniture, although it is not required with every firing it pays to keep an eye on it, especially if glaze has melted onto the shelf and needs removing.
If you have a top loader
Check your lid, be aware of the condition your lid band is in. Does it look like it might break or has it come loose? We have a number of customers who have ruined pottery or worse broken the bricks in the lid and needed to replace it completely because the lid band snapped or became loose, these are both avoidable, with a bit of awareness and a spare lid band on hand.
Regular Kiln Maintenance Inspections:
Visually inspecting the elements
Checking for rust, thinning or thickening areas will help you determine if the kiln elements need replacing, there are a few tests you can perform to see how they are performing.
The kiln element tissue test
By placing a small tissue on each element and firing your kiln to a low temperature such as 200 Celsius or for larger kilns you may need to run at a higher temperature, to ignite the middle elements, heat just long enough to see if the tissues have burned or elements have warmed. If all tissues burn or elements are warm then they are working along with the relay.
If your kiln elements are still firing but you are finding your kiln has started to fire slowly or not reaching temperate this could be a sign your elements need replacing. As elements wear out by usage and temperature for instance if you are firing at higher cone settings often, this will wear out the elements faster than lower temperatures.
Why relay switches are a vital part
Relay switches turn on your elements, depending on the size of your kiln you may have 2 – 3 relays generally each relay switches on two elements at a time. Following a tissue test or checking the elements are warm (do not check when red hot), if this shows that two elements did not come on at all, then this could indicate that a relay switch needs replacing not the elements.
Looking for signs of kiln wear or metal corrosion
Depending on where your kiln is placed this will affect the longevity of metal parts, if you have a metal lid band, or the outer of your kiln is metal it will be susceptible to corrosion and rust. Ensure you have a dry well insulated and ventilated room to place your kiln. If it is in a shed with no wall insulation to stop condensation or if you live in a humid wet climate or near the ocean this all plays a part in the parts life span.
Rust on the outer of your kiln is cosmetic and won't affect the function of your kiln. Metal parts however like hinges and lid bands need regular checks. Keep a lid band replacement on hand (for top loaders) as you could save valuable downtime and money, if you see that the band needs attention by replacing it you can avoid a break and the potential for your whole lid to burst and break.
Check the kiln's lid or door for proper sealing
Gaps can affect temperature distribution as kiln bricks shrink and expand each time your kiln is used, this can leave cracks over time.
Kiln brick maintenance
Regular checks will help you identify if there are any cracks that need firebrick cement to fix. Note most hairline cracks are cosmetic and won’t affect the kiln, if you think the cracks are becoming too large or are in the kiln lid we recommend using kiln firebrick cement, be careful not to get it on your elements as this could end in an electrical shortage and element replacement.
Kiln lid band tightening
Due to the expanding and shrinkage over time, it can affect the lid band on top loaders, regular checks will help you identify if the lid band needs tightening.
Ceramic fibre insulation
Some kilns and front loaders may use ceramic fibre insulation blanket, or if you need to insulate around vents, this can be replaced. Check your kiln manual for more details.
Thermocouple maintenance
Check the tip for corrosion if there is surface rust you can lightly brush it off and clean it before putting it back in place. Ensure the wires connecting your thermocouple are secure and not frayed. Once you have screwed the thermocouple back in place, check the temperature readings to ensure that the thermocouple is now functioning properly. If it appears healthy and you are still having issues, check your control board.
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Peephole plug replacement
Peepholes last a long time, but if you see it worn down by repeated heat and fumes and it is cracked or starting to crumble it might be a good time to replace it.
Conclusion:
Having spare elements, a relay, lid band and fuses on hand will minimise downtime and prevent unexpected firing interruptions.
Understanding common kiln issues and knowing how to diagnose and address them is also a significant part of maintenance. Consult your kiln's manual for specific maintenance schedules and recommended spare parts, as models vary in their requirements.
Need to dive deeper? try these helpful links:
Need to replace kiln parts?
