Pottery Kilns & Equipment Supplies; Kiln Servicing, Kiln Health & Safety Audits and Teacher Training for Schools & Colleges; Clays & Glazes etc supply for Educational & Studio / Hobby Potters.

FAQs

Listed below are some of the most frequently asked questions that we receive. We are always pleased to help customers whenever possible, however, as individual queries and circumstances may vary, our responses should always be viewed as general guidance for information purposes only.

I have heard that our school is responsible for making sure that our Kiln Engineer is competent to service the school kiln. Is this correct and if so, how do we know that he is competent?

This is true. Under the Management of Health and Safety at Work Regulations 1999 act the school bears full responsibility and liability for ensuring that their chosen kiln service engineer is adequately qualified and fully competent. The quickest and easiest way to ascertain competency is via a third party accreditation such as the National Inspection Council for Electrical Installation Contractors (NICEIC). Their websitewww.niceic.comlists all of their registered members who have been assessed as competent by NICEIC by way of annual qualification reviews and work inspection. In addition NICEIC also check that their registered members carry adequate insurance and that their test instruments are accurately calibrated and certified.

Is it safe for me to leave our school kiln firing unattended overnight?

The answer to this perennial question is a simple “No,Not Unless”!…..The principal risk with an unattended kiln is fire if the kilns controller or contactor fails, leaving the kiln to fire up to a “self destruct” temperature o a round 1480°C. Providing you undertake a Risk Assessment and control this risk with Over temperature Protection through an Independent Heatfuse, then there is no reason that your pottery kiln cannot be left firing overnight.
Detailed over temperature risk assessment guidance is available free of charge from Celtic Kilncare. Please request Data Sheets K.03 and SB01/03.

Is there anyway that I can prolong the life of my kilns heating elements?

Yes. If you are able to use ceramic glazes with a lower maturing temperature, ideally earthenware or stoneware not exceeding 1250°C this will help, as lower firing temperatures will always extend the life of your elements. Hot spots also shorten element life and these can be prevented by avoiding ceramic glaze contamination, vacuuming out ceramic debris from the element channels and not stacking ware too close to the elements. Occasional annealing of the elements by heating the kiln whilst empty to 850°C and letting it cool slowly can also help.

I have started teaching in a new school and the kiln that I have “inherited” does not have a service record except for an “OK” sticker on it. Is it “OK” to use this kiln?

No, definitely not. When a pottery kiln is serviced a detailed record of the tests carried out a long with a report must be left with the kiln operator or owner in order to comply with current legislation.
In order to comply with the IEE 17th Edition Regulations the record must show actual measured test values of earth continuity and insulation resistance. Actual current drawn is also a useful measurement to record. A record that only shows “ticked” pass or fail boxes or is simply marked OK is not compliant.

Why do the coil of my kilns elements keep bunching up towards the front of the kiln?

Coil bunching occurs through them igration of the coils when the element cools at a different rate between the front end and the back end of the element. This i usually caused by opening th kiln door whilst the kiln is still too hot. Do not open the kiln door until the chamber temperature is within 10°C of the ambient room temperature. If the bunching appears towards the rear of the kiln, this would suggest that the element tail feed holes are allowing accelerated heat loss and need repacking with MMVF.

One of my kilns heating elements has burnt out. Should I replace just the broken element or the entire set?

If the element has burnt out from an obvious cause e.g. glaze contamination or impact from a falling pot or shelf and all the other elements are in good condition, then it is probably acceptable to replace just the offending element. If however the element is one of a tired set, typically over 100 firings “old” and/ or showing signs of coil collapse and heavy oxidisation, then it is time to replace the entire set otherwise you will unbalance the pottery kiln and end up replacing the set “one at a time” over the next dozen or so firings,-a very expensive exercise!

A competent service engineer would b able to measure the resistance of the remaining elements, calculate their % efficiency drop from new and advise whether best to replace the single damaged element or the entire set.

I use my pottery kiln in a spare room that I have converted into a studio at home. Do I need to have my kiln serviced on a regular basis?

As long as you are not employing anyone who comes into contact with the pottery kiln and the general public are not allowed access to the kiln area, then the Health and Safety at Work etc Act would probably not apply to you and you would have nolegalobligation to have the kiln serviced, however, we would consider it extremely unwise and potentially dangerous if you did not have the kiln service date least once a year.

You may also find that your insurance company (make certain you advise your insurer that you are operating a kiln on your property) would not honour any claim for property fire damage caused by your kiln if you were unable to demonstrate proper service and maintenance records for the kiln!