Guidelines for selecting a kiln
Our selection of kilns have grown steadily over the last few years.
With so many available options, making a decision could be somewhat overwhelming. To help you sort through the confusion use these steps to guide you towards selecting the kiln that best suits your needs. If you have more questions, our dedicated team is only a click, email, or phone call away.
Step 1: Electric or Gas?
Electric kilns are easier to manage and tends to be safer. With the exception of large Industrial kilns that use ‘piped’ Sasol gas, small installations using bottled gas tends to have a higher running cost than its electric equivalent.
Traditionally gas has always been used for ‘reduction firing’, Raku work, and for temperatures higher than 1400°C.
Step 2: Electricity Requirements
People often overlook the power that is available to run a kiln. There are two main types available in South Africa: Single Phase or Three Phase.
Most residential homes only have 60 amps, single phase electricity supply. When selecting a kiln, check the specifications to see if it needs single or three phase power. This does limit your choices as very few kilns are able to run from a normal household plug. We do not recommend installing kilns larger than 7 cubic feet (cu ft).
In most cases a small amount of work will be needed to meet the legal requirements for an electrical installation. A qualified electrician will need to add a suitable breaker, appropriate wiring, an isolator switch and possibly an additional breaker on you main distribution box. This is not an expensive exercise but vitally important to ensure your electric connection is safe and up to code.
There is no significant cost difference between using single or three phase electricity, it comes down to what type you have available. You can apply to have Three Phase electricity installed at your premises if this is the route you wish to take.
Step 3: Type if kiln
Before selecting a kiln consider the type of work you want to use the kiln for, the size of the items you plan to produce, the quantities you would like to make with each firing, and how often you intend to fire. Kilns come in different sizes, so make sure the heat chamber is large enough for the items you are planning to produce.
The most commonly used kilns are front and top loaders with both having pro’s and con’s. Let’s have a look at some of the kilns available.
Front Loading
These kilns are easier to pack and unpack. They are fitted with a front opening door and most are made with a stand. Smaller options without a stand can be placed on a table top or bench. Front loading kilns are sturdy and heavy, making them hard to move.
Top Loading
Conventional top loaders tend to be smaller, taking up less space, and have a round or oval fire chamber. They are ideal for small work areas and can be fitted with wheels, making them easier to move around.
They tend to be less expensive and the smaller ones will work on a standard household, single phase socket. Beginners often prefer to start with a top loading kiln as it requires a smaller initial investment.
They are harder to load. You need to load them from above and need to layer the shelves as you pack the kiln. They are also lower and you would need to bend
over to pack them, taking its toll on your back.
Top loaders are not built with a sturdy metal frame and depend on the internal insulating bricks for their rigidity. It is more prone to damage if treated roughly.
Glass slumping & fusing
Traditional glass slumping and fusing kilns looks like a large square box with a top opening lid. Because of their shape they are often called ‘coffin kilns’. They tend
to be wide and shallow to allow space for flat sheets of glass that can be fused or slumped over a mould.
Glass needs radiant heat to soften and mould. Because most of the work starts out flat the majority of the heat is designed to come from above.
These kilns cannot be used to fire pottery as the maximum temperature they achieve are about 900°C. This is too low for ceramics.
Custom Kilns
There are many different types and shapes of kilns used for various applications and in many industries. The need for heat is widespread and varied and we can design and build a kiln to your specifications and heating requirements.
Step 4: Size
Select a kiln that will be capable of firing the largest item you will produce, consider how long it will take you to make enough pieces to fill your kiln, and decide how often you want to fire.
Do you think your current production will increase over time? Kiln owners will typically tell you to select a kiln with larger capacity than your current needs, because as you grow your hobby or business, you will outgrow your current kiln as well.
To determine which size best suits your needs, consider the following:
- What type of items/products do you plan to produce?
- If you make larger pieces, do you make them regularly or on the odd occasion? Can you fire your
larger pieces off-site? - What quantities do you wish to produce?
- For maximum efficiency you need to fire a fully loaded kiln. Think about the time it would take to
make the items you need to fill your kiln.
A small kiln is great if you make dolls, jewellery, or smaller items. If you make larger items and quantities or
throw (which is considerably faster than hand-building), we recommend a kiln of at least 5 cu ft.
Step 5: Control Options
Manual kilns are obsolete and only die-hard enthusiast still prefer this method of firing. It requires constant attention and vigilance. You will need to be in the vicinity at all times to monitor the firing cycle. This requires time, that most of us do not have.
In you search for a kiln, you might encounter an Automatic kiln that is fitted with a kiln sitter. This is a mechanical system that uses a cone, placed in the kiln sitter. Once your kiln reaches the desired temperature, the cone folds over, and triggers the kiln sitter to switch the kiln off. Although effective, this mothed is dated. Your kiln can easily be converted to digital. Still need convincing? Read the benefits below.
Benefits of using a Digital Controller:
- It requires less of your time. You program the firing cycle, press start, and the digital controller does the rest.
- If the electricity should go off for some reason (load shedding), your controller will automatically start your kiln up again when the power is back, recalculate, and continue with the firing cycle.
- You will never need to use a cone again. The controller regulates and monitors the temperature of your kiln.
- You can program up to 36 firing cycles into your controller. One for every type of clay or glaze you might want to fire. Next time you need to fire some Porcelain, select the program and press start.
Programmable controllers are suitable for work in all mediums.
We will be launching a controller you can manage via Wi-Fi. Digital will soon go wireless. Most manual and mechanical kilns can be easily converted to digital.
Step 7: Kiln Furniture
You will need to consider the shelves and props you will need for your kiln. The type of kiln, size of your items and the way you will pack your kiln will determine how many shelves and props you will need to use your kiln’s capacity to achieve maximum efficiency.
Step 8: Making the ultimate decision
We hope this information will steer you towards choosing the kiln that will suit your needs and budget. We do try and keep the most commonly used kilns in stock, if however it needs to be manufactured it can take up to 4-6 weeks. Contact us for more information or a quotation.
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