The Paragon Caldera series kilns are usually used for ceramics, enamels, firing metal clays, glass work, heat treating, making jewellery, and porcelain. They're 1290°C, four-sided, top-opening, firebrick kilns, either with manual rotary controllers and separate pyrometers, or automatic ramp-hold cone-fire Sentry Xpress 3-key digital programmers.

You can make bangles, beads, bowls, bracelets, brooches, charms, dolls, earrings, figurines, fingerprints, garden ornaments, glass-art, jewellery, keepsakes, knives, lampshades, model parts, mugs, necklaces, pendants, plates, porcelain beads, pots, rings, seasonal decorations, souvenirs, stained glass designs, thimbles, tiaras, tiles, and vases.

You can try Art Clay metal clay, bronze clay, copper clay, PMC silver clay, glass clay, Accent Gold, Image Transfer Solution, Metal Clay Veneer, SilverEtch, bead annealing, ceramics, china painting, dichroic glass, enamelling, glass art, glass fusing, sagging and slumping, glazes, heat treating, knife-making, laboratory testing, lampwork, lost-wax casting, making jewellery, melting gold and silver, porcelain, pottery, raku, and staining glass. And work with many other materials and processes.

They're ideal for your arts centre, ceramics studio, college, course venue, engineering workshop, glass works, jewellery studio, medical laboratory, school, or technical facility.

Cherry Heaven TV has made an on-line photo book featuring these popular kilns: click the Cherry Heaven TV player above. It starts with the FireFly-S, and continues with the larger Caldera and Caldera-XL.

I've included the FireFly as the FireFly series is very similar to the Caldera series. The FireFly costs a little less as it's 114mm high internally, whereas the Caldera is 171mm high internally.

To look at the pop-up photos, hold your mouse over the zoom buttons below: you don't need to click.

The Paragon Caldera-S.

The Paragon Caldera-S.

The Paragon Caldera-SW.

The Paragon Caldera-A.

The Paragon Caldera-AB.

The Paragon Caldera-AW.

The Paragon Caldera-XL.

The Paragon Sentry Xpress 3-Key Programmer.

This comprehensive internet resource lets you research and compare kilns in your own time. There's a lot to read, but you'll make the right choice instead of an expensive mistake. The section about kiln furniture is very important.

For small plug-in table-top kilns for annealing, beads, dichroics, enamels, fusing, keepsakes, making jewellery, metal clays, mixed-media work, and porcelain, or for large wired-in floor-standing and work-top kilns for casting, ceramics, glass, heat treating, knife making, pottery, and raku, use the links above or below the menu bar near the top of the page.

The Paragon Caldera series kilns are usually used for ceramics, enamels, firing metal clays, glass work, heat treating, making jewellery, and porcelain. They're 1290°C firebrick, four-sided, top-opening kilns, either with manual rotary controllers and separate pyrometers, or automatic cone-fire ramp-hold Sentry Xpress 3-key digital programmers.

There are seventeen in the series, based on three body versions: the manual Caldera-S, the automatic Caldera-A, and larger automatic Caldera-XL, leading to the Caldera-S, SB, SC, SE, SW, SBW, SCW, and SEW, the Caldera-A, AB, AC, AE, AW, ABW, ACW, and AEW, and the Caldera XL.

The kilns have elements in the front, back, and both sides, so can't accommodate a bead door. However, the Caldera-S and Caldera-A can both accept a separate clip-on layer called a collar: as a plain collar, a collar with a bead-annealing door, or a collar with an enamelling door, all of which increase the internal height by 110mm.

However, the collars don't have any elements, so the plain collar and the bead collar reduce the maximum temperature to 1095°C cone 3, and the enamelling collar reduces it to 980°C. To use the kiln at 1290°C cone 10, unclip the collar.

They're popular for mixed-media work in a commercial studio or a small business: everything from quick enamelling to firing porcelain. They're very versatile and will do most things for most people within their size limits.

Paragon's naming conventions aren't consistent. Although there was probably a useful plan many years ago, it's worth trying to understand where we are now:

The manual Caldera was called the Caldera-S, and the digital Caldera just called the Caldera even though elsewhere B was used for a stainless-steel case and D was used for digital. The plain collar version was called the Caldera-X, the bead-door collar called the Caldera-BC, and the enamelling collar called the Caldera-E. This is confusing because the X, BC, and E are just extra layers, or collars: not complete kilns. The suffixes B, E, W, and BW weren't used, although they should have been?

So, rely on the actual descriptions. The model names we use have suffixes which describe the model and collar. For example, for automatic kilns: the Caldera AB has a collar with a bead-annealing door, the Caldera-AC has a plain collar, the Caldera-AE has a collar with an enamelling door, and the Caldera-AW has a heat-resistant glass viewing-window.

The bead collar includes a 165mm x 64mm letter-box style bead-anealing door and a bead-mandrel holder, and the enamelling collar includes a 165mm x 101mm letter-box style enamelling door.

All versions can have a heat-resistant glass viewing-window in the centre of the lid, as the manual Caldera-SW, Caldera-SBW, Caldera-SCW, and Caldera-SEW, the Caldera-AW, Caldera-ABW, Caldera-ACW, and the Caldera AEW, and the larger Caldera-XLW. In the table below, the SC2 and Xpress-E12A are included for comparison.

The window reduces the maximum temperature to 1150°C. To use the kilns at higher temperatures, push a small pad of ceramic-fibre cloth behind the glass.

Although the choice seems overwhelming, it's really quite simple. Choose the manual Caldera-S, the automatic Caldera-A, or the automatic Caldera-XL. Then think about a plain collar, a bead collar, or an enamelling collar. Think about a window. Then think about any appropriate options, upgrades, and extra shelf kits.

If you want a smaller, simpler, economy kiln, look at the 1000°C front-opening Kitiki MiniKiln, or the 1095°C front-opening Paragon SC2. If you want a larger kiln look at the Xpress-E12A. I've included a specification table below showing the standard models, not all the upgraded versions.

If your want a floor-standing. top-opening. ceramics kiln, look at the six-sided Xpress 1193, seven-sided 66-3, and eight-sided 1613.

The kilns heat evenly from all four sides, not from both sides and the back. This prevents the front-to-back temperature difference that's common with smaller kilns.

The elements lie in pin-less grooves in the firebrick, and are quick, easy, and inexpensive to replace in the unlikely event of a failure. If your business depends on your kiln or you're running courses, it's a good idea to have a spare element. You can buy spare elements in the on-line shop.

The kiln lid hinge has an integrated cut-off switch, included in the price: an important safety feature if you want to open the lid or bead door whilst you work. However, never get careless: kilns are very hot and connected to the mains.

The Caldera kiln was intended to be a stackable kiln with a separate lid and bottom. However, the lid must be hinged to the Caldera body when a lid-activated safety switch is installed. To stabilize a Caldera kiln that has a hinged lid, the kiln body and kiln bottom are held together with two latches.

If an unlatched collar (plain, bead, or enamelling) is mounted between the Caldera body and the kiln bottom, care must be taken when opening the hinged lid. Do not open the lid past 90 degrees unless the lid leans against a heat-proof support behind the kiln.

The Orton Sentry digital programmers allow you to set up multiple sequences, each one with multiple heating, holding, or cooling segments: so you can choose the heating and cooling rates, target temperatures, and hold times, save the sequences, and re-use them. There are no restrictive features such as single-sequence use or pre-set programmes.

Pre-set programmes might seem to be an advantage. However, having experimented and diversified, many people fire materials, or combinations of materials, at different temperatures and for different times than are recommended.

The Caldera-A is an automatic kiln. Its digital programmer allows you to set up and save four automatic sequences, each one with up to eight segments.

A segment is one step in the sequence. For example: a segment could take 50 minutes to reach 1050°C, another could hold at 850°C for 15 minutes, or another could cool down to room temperature over 4 hours.

The Caldera-S is a manual kiln. Its rotary switch does not offer sequences and segments: you have to stay by the kiln to adjust the heating and cooling rates, and turn it off at the end.

For many people doing small-scale work, that's enough, although it helps if you buy a pocket digital timer to remind you that time's up. You can buy a digital reminder timer in the on-line shop.

It's very important to understand that the Caldera-S has a rotary switch, not a digital programmer. There are limitations, although you may be perfectly happy with what it can do rather than unhappy with what it can't.

The Caldera-A digital programmer allows you to set up and save four drying, heating, holding, and cooling sequences, and do something else whilst the sequence is running. A sequence can consist of up to eight segments.
A segment is one step in the sequence. For example: a segment could take 50 minutes to reach 650°C, could hold at 850°C for 15 minutes, or could cool down to room temperature over 4 hours.

The Caldera-S rotary switch does not offer sequences and segments: you have to adjust the heating and cooling rates, and turn the kiln off at the end. For most people doing small-scale work, that's enough, although it helps if you buy a pocket digital timer to remind you that time's up. You can buy a digital timer in the on-line shop.

An option is usually a cosmetic or practical variation, such as a pink respray, a right-hand hinge, a bead door, or an EU plug. An upgrade goes beyond the standard specifications, such as a higher temperature, a 12-key programmer, an electric kiln vent, or a USB interface. The photo shows a Paragon SC2 customised for an Art Clay and PMC studio: pink, with a RH hinge, and a maximum temperature of 925°C.

The kilns in this series are described in detail further down the page. It's important to read everything carefully so that you understand what they can and can't do, why some of the accessories, options, and upgrades might be useful, and how they compare with other kilns.

Not every option or upgrade applies to every kiln in this series. However, if they're appropriate, they're listed in the on-line shop, so just add up the ones you want: but order them with your kiln as they're often difficult, expensive, or impossible, to implement afterwards. It might help if you make a few notes of your own now? Mail or call if you need help deciding.

They use regular single-phase 230V mains so have 230V EU elements, not 120V US elements. They have UK 13A three-pin plugs: so they're ready to go. If you're not in the UK, use a plug adapter or cut off the UK plug and fit your own: it won't invalidate the guarantee. Alternatively, a special-order kiln can have an EU plug factory-fitted.

Most kilns can be re-engineered for 110V, 200V, 208V, or 240V, single phase or three phase, or 440V three phase. If you're interested, mail or call.

Although standard EU and US kilns have the same maximum temperature, set by the design and the programmer, some 1095°C firebrick kilns can be re-engineered to run at 1230°C, 1260°C, or 1290°C, making them versatile mixed-media kilns.

However, virtually everything can be done at less than 1260°C. At 1290°C, conventional kiln materials are nearing their limit so I suggest you only use 1290°C occasionally rather than full-on hour after hour.

Also, to maintain 1290°C, some upgraded kilns might need thicker firebricks, so they'll be slightly smaller inside: about 12mm on each side. Mail or call if you're interested, or need help deciding.

Kilns in the BlueBird, SC, and Xpress series are normally blue, but can be painted black, pink, purple, or turquoise. However, as they're made to order, they can't be returned if the colour isn't exactly the same as in the photo.

The door hinge is usually on the left. However, a right-hand hinge might be better if you're left-handed: unless the kiln will be in the left-hand corner of your studio or there's an obstacle that will make access difficult. Give this some thought.

Most of the medium-size kilns have a standard lift-up lid. Firebrick lids seem heavy to some people so, if you feel that a hydraulic-assisted or spring-assisted lid would be easier, mail or call.

If the kiln comes with a Sentry Xpress 3-Key ramp-hold programmer, you can upgrade to a Sentry Xpress 3-Key cone-fire and ramp-hold programmer, usually preferred for ceramics. Cone-fire is implemented in the programmer's software and is very easy to use: just set a cone number and start the firing sequence.

Or, you can upgrade any Sentry Xpress 3-key programmer to a Sentry 12-Key ten segment ramp-hold, or cone-fire and ramp-hold, programmer, with advanced firing features and connection options. The 3-key has a 12-month guarantee and the 12-key has a 30-month guarantee.

The Sentry 12-key programmer can be connected to your computer through a factory-fitted USB interface. The Control Master software allows you to control and monitor the firing, and analyse, arrange, print out, and save the data. If you want this feature, make sure you order the USB interface.

Most kilns come with a standard long-lasting electro-mechanical relay. However, if long-life and reliability are vital, you can upgrade to a mercury relay which has a lifetime of several million on-off cycles. Remember that some of the larger kilns have two or more relays.

Some bronze and copper clays, and some metals, need to be fired in activated charcoal granules in a stainless steel container. The SC2 and SC3, the Caldera-A, and the Xpress E9A. E10A, and 1193 can hold a one-litre container: most other kilns can hold a three-litre.

Particulates represent a health risk if they're breathed in, so wear a HEPA mask when cleaning out your kiln, mixing kiln wash, and working with charcoals, ceramic-fibre blocks, cloths, and papers. And, ideally, use protective glasses.

If you want to touch anything hot or move your kiln before it's cooled off, it's important to wear heat-resistant gloves. And, if you want to look into a red-hot kiln, wear glare-resistant glasses which protect your eyes from IR and UV.

Paragon kilns, made in the US, have been re-engineered and comprehensively tested for the UK, the EU, and most other countries. They're CE Marked and comply with EU safety standards. They're guaranteed for a year, and Paragon has an international, informed, and supportive user-base, and spares and repair centres.

The digital programmer shows degrees Celsius, not degrees Fahrenheit as in the US. If you need to convert, this is how to do it. However, if you want to work in Fahrenheit, you can make a simple change to the programmer.

In the unlikely event that your kiln develops a fault, it's reassuring to know that home repairs are easy and need little more than a screwdriver and a pair of pliers. An engineer can guide you on the phone, and there are on-line repair videos.

Re-freshing the air in a kiln minimises surface blemishes when firing clays, ensures brighter colours when firing glasses, and prevents colour contamination when firing different glazes.

A factory-fitted Orton Vent Master removes airbourne pollutants straight away and redirects them to the outside. Most kilns can be factory-readied: the vent just needs on-site assembly.

Venting the kiln has little effect on the heat-up time and the maximum temperature. However, the cooling time is reduced considerably, depending on the size of the kiln,

The UK vent motor is rated at 230V 132W, so it can use a regular mains socket. The suction cup and pipe are attached to the kiln but the motor can be remote: it doesn't get hot and the fan is easy to clean.

There's always a small gap, for expansion, around any kiln door or lid, so enough new air can be drawn in to replace the old air being drawn out. However, peepholes act as straight-through cold-air inlets: so you might not want them?

The VentMaster can be turned on and off manually. Alternatively, if the kiln has a Sentry 12-key programmer it can be plugged into the kiln's auxilliary power outlet and controlled by the programmer. The power outlet has to be fitted during manufacture, so decide before you order.

As with Paragon kilns, Orton Vent Masters can be re-engineered for any electrical system. They conform to the demanding 1992 Uniform Mechanical Code and the UL standard, and are CE Marked for the EU. They have a two year limited warranty.

Every kiln comes with kiln furniture, included in the price, so that you can start work straight away. It's not an expensive collection that I've put together for you: one that you have to pay for but might never use.

What you get depends on which kiln you choose. For example: one full shelf, two half-shelves, several mixed shelves, a set of shelf posts, a bead-mandrel holder, glass separator, hot gloves, kiln wash, a knife-making rack, pyrometric cones, a tile holder, or other accessories. So, it's important to understand what's in the included furniture kit for the kiln you've chosen.

Usually, a shelf kit comprises one professional, durable, cordierite shelf and four 12mm high posts. It should stay on the floor of the firing chamber all the time in case you accidentally spill or melt anything: solidified glass is impossible to pick off without damaging the ceramic-fibre or firebrick. You don't get a soft, ceramic-fibre shelf, often described as free, that will gradually break up and need replacing.

During firing sequences with heating, holding, and cooling segments, the elements turn on and off repeatedly. In a small kiln, with little residual heat, the inevitable temperature changes can make glass crack as it expands and contracts. A thick heavy shelf stores heat and, because it's resting on posts, the air circulates, helping to even out any normal temperature fluctuations.

If you're buying your first kiln, you're probably interested in one material, such as silver clay, or one process, such as enamelling. However, after a few successes, and failures, most people want to try different materials, make larger pieces, experiment with combinations, fire more at a time, and soon become interested in something else: or everything else. Some start a business or run classes.

Depending on the material or process, and the sizes of your pieces, shelves can be stacked up on posts to make better use of the kiln space, your time, and the unit firing-cost: so you might want extra shelf kits.

If extra shelf kits are packed with the kiln, the delivery charge doesn't increase. Ordered later, not with the kiln, they need a box and protective packing and attract an extra delivery charge. Outside the UK mainland, this might be expensive. So, if you think you'll need them, order them with your kiln, along with any other accessories, materials, parts, or tools.

Although they look tough, most ceramics break if they're dropped, so it's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses.

Shelf kits usually include 25mm x 25mm x 12mm shelf posts, When flat, they're 12mm high: on their sides, they're 25mm. Other sizes, up to 150mm high, are available, so you can choose the shelf spacing that suits your kiln and your work.

For dichroics, enamelling, and glass fusing, put kiln paper on the shelf to stop the glass sticking: it's simpler and cleaner to use than glass separator. Bullseye Thinfire shelf paper, probably the most popular, ensures easy separation between your glass and the kiln shelf. One side feels slightly smoother than the other: that's the glass side.

Generally, glasswork needs radiant heat and will fuse, sag, or slump better on one shelf than between closely stacked shelves, although experienced glass artists often use several shelves succesfully.

Delicate pieces can be fired on a puffed-up ceramic-fibre cloth: on a shelf. Round pieces, that could roll to one side, can be fired on a hollowed-out ceramic-fibre block.

Particulates represent a health risk if they're breathed in, so wear a HEPA mask when cleaning out your kiln, mixing kiln wash, and working with ceramic-fibre blocks, cloths, and papers. And, ideally, use protective glasses.

If you want to touch anything hot, or move your kiln before it's cooled off, it's important to wear heat-resistant gloves. And, if you want to look into a red-hot kiln, even briefly, wear glare-resistant glasses to protect your eyes from IR and UV.

If your day-to-day work depends on your kiln and down-time will be disruptive or expensive, it's a good idea to have spares: extra shelves, a selection of posts, elements, a relay, and a thermocouple.

You can learn about ceramic blocks and cloths, charcoal, dust masks, glare-resistant glasses, glass separator, heat-resistant gloves, kiln vents, kiln wash, programmers, protective glasses, USB interfaces, shelf paper, tools, and other accessories, using the accessories link below the menu bar near the top of the page. And they're all in the on-line shop.

The Paragon Caldera-S is a plug-in, table-top kiln, usually used for ceramics, glass work, heat treating, making jewellery, metal clays, and porcelain. It's a 1260°C, cone 10, four-sided, top-opening, firebrick kiln, with an easy-to-use rotary switch and an analogue pyrometer.

You can make bangles, beads, bowls, bracelets, brooches, charms, dolls, earrings, figurines, fingerprints, garden ornaments, glass-art, jewellery, keepsakes, knives, lampshades, model parts, mugs, necklaces, pendants, porcelain beads, pots, rings, seasonal decorations, souvenirs, and thimbles.

You can try Art Clay metal clay, bronze clay, copper clay, PMC silver clay, glass clay, Accent Gold, Image Transfer Solution, Metal Clay Veneer, SilverEtch, bead annealing, ceramics, china painting, dichroic glass, enamelling, glass art, glass fusing, sagging and slumping, glazes, heat-treating, knife-making, laboratory testing, lampwork, lost-wax casting, making jewellery, melting gold and silver, porcelain, pottery, raku, and staining glass. And work with many other materials and processes.

The UK kiln is rated at 230V 1800W, so it can use a regular mains socket. To comply with EU safety regulations, it's fitted with an additional lid-activated switch that cuts off the power if the kiln is opened: an important safety feature included in the price. However, never get careless: kilns are very hot and connected to the mains.

The kiln is made in two clip-together parts: a firebrick base, and a firebrick firing chamber with a hinged firebrick lid. The outer steel case measures 331mm x 495mm x 349mm high, including the rotary switch and pyrometer housing and other hardware. The shipping weight is about 19Kg.

The firebrick firing chamber measures 203mm x 203mm x 171mm high and heats from the front, both sides, and the back, with the fast-firing elements lying in pinless dropped-recessed grooves in the 64mm thick bricks.

The programmer's digital display prompts for cone numbers, or heating rates, target temperatures, and hold times, making it easy to set up and re-use accurate heating, holding, and cooling sequences.

Unlike the Caldera-A, the Caldera-S doesn't have a digital programmer. However, the rotary switch allows you to set the elements-on time and therefore the heating rate and final temperature. It's a 20-100 style: on the lowest setting, the elements are on 20% of the time; on the highest setting, the elements are on 100% of the time.
The analogue pyrometer, included in the price, gives temperature feedback, so that you can regulate the heating and cooling rates. For more accurate feedback, useful for temperature-sensitive materials and processes, you might want a digital pyrometer. You can buy digital pyrometers in the on-line shop.

There's a recommended kit, included in the price: one 178mm x 178mm x 15mm cordierite shelf, four 12mm shelf posts, and 450gm of glass separator.

There's an extra recommended kit, not included in the price: one 178mm x 178mm x 15mm shelf and four posts. You can choose 12mm, 25mm, or 50mm posts.

Depending on the material or process, and the sizes of your pieces, stacked shelves will hold more work, free up your time, and reduce the unit firing cost: so you might want more kits. This kiln has room for three.

The Paragon Caldera-SW lid includes a 50mm x 50mm heat-resistant glass viewing-window. Otherwise, it's the same as the Caldera-S.

The Paragon Caldera-SBW lid includes a heat-resistant glass viewing-window, 50mm x 50mm. Otherwise, it's the same as the Caldera-SB.

The Caldera-S can accept a separate removable layer, called a plain collar, which increases the internal height from 171mm to 281mm but reduces the maximum temperature to 1095°C cone 3, making it a Caldera-SC. To use the kiln at 1290°C cone 10, remove the collar.

The plain collar sits on the base, and the firebrick firing chamber sits on top. The extra height allows you to fire taller pieces of work, or use two extra shelves, making five in all. Otherwise it's the same as the Caldera-S.

The Paragon Caldera-SCW lid includes a 50mm x 50mm heat-resistant glass viewing-window. Otherwise, it's the same as the Caldera-SC.

The Paragon Caldera-A is a low-cost mixed-media kiln. It's a 1290°C cone 10, four-sided, square, firebrick, top-opening kiln, with an easy-to-use, ramp-hold cone-fire, Sentry Xpress 3-key digital programmer.

You can try Art Clay, BronzClay, CopprClay, and PMC metal clays, GlasClay, Accent Gold, Metal Clay Veneer, china paints, ceramics, porcelain, pottery, stoneware, china paints, making beads, bead annealing, dichroic glasses, enamelling, heat treating, melting metals, mixed-media jewellery, lost-wax casting, glass fusing, sagging and slumping.

The UK kiln is rated at 230V 1800W, so it can use a regular mains socket. To comply with EU safety regulations, it's fitted with an additional lid-activated switch that cuts off the power if the kiln is opened: an important safety feature included in the price. However, never get careless: kilns are very hot and connected to the mains.

The kiln is made in two clip-together parts: a firebrick base, and a firebrick firing chamber with a hinged firebrick lid. The outer steel case measures 331mm x 495mm x 349mm high, including the programmer housing and other hardware. The shipping weight is about 20Kg.

The firebrick firing chamber measures 203mm x 203mm x 171mm high and heats from the front, both sides, and the back, with the fast-firing elements lying in pinless dropped-recessed grooves in the 64mm thick bricks.

The electronic display prompts for heating rate, target temperature, and hold time, making it easy to set up and re-use accurate drying, heating, holding, and cooling sequences.

There's a recommended kit, included in the price: one 178mm x 178mm x 15mm cordierite shelf, four 12mm shelf posts, and 450gm of glass separator.

There's an extra recommended kit, not included in the price: one 178mm x 178mm x 15mm shelf and four posts. You can choose 12mm, 25mm, or 50mm posts.

Depending on the material or process, and the sizes of your pieces, stacked shelves will hold more work, free up your time, and reduce the unit firing cost: so you might want more kits. This kiln has room for three.

The Caldera-A can accept a separate removable layer, called a bead-door collar, which increases the internal height from 171mm to 281mm but reduces the maximum temperature to 1095°C cone 3, making it a Caldera-AB. To use the kiln at 1290°C cone 10, remove the collar.

The bead-door collar includes an outward-opening letter-box style door, 165mm x 64mm, and a mandrel holder. It sits on the base, and the firebrick firing chamber sits on top. The extra height allows you to fire taller pieces of work, or use two extra shelves, making five in all. Otherwise it's the same as the Caldera-A.

The Paragon Caldera-AW lid includes a 50mm x 50mm heat-resistant glass viewing-window. Otherwise, it's the same as the Caldera-A.

The Paragon Caldera-ABW lid includes a 50mm x 50mm heat-resistant glass viewing-window. Otherwise, it's the same as the Caldera-AB.

The Caldera-A can accept a separate removable layer, called a plain collar, which increases the internal height from 171mm to 281mm but reduces the maximum temperature to 1095°C cone 3, making it a Caldera-AC. To use the kiln at 1290°C cone 10, remove the collar.

The plain collar sits on the base, and the firebrick firing chamber sits on top. The extra height allows you to fire taller pieces of work, or use two extra shelves, making five in all. Otherwise it's the same as the Caldera-A.

The Paragon Caldera-ACW lid includes a 50mm x 50mm heat-resistant glass viewing-window. Otherwise, it's the same as the Caldera-AC.

The Paragon Caldera-XL is a high temperature, low-cost, mixed-media kiln. It's a 1290°C cone 10, four-sided, square, firebrick, top-opening kiln, with an easy-to-use, ramp-hold cone-fire, Sentry Xpress 3-key digital programmer.

The Paragon Caldera-XL is suitable for Art Clay, BronzClay, CopprClay, and PMC metal clays, Accent Gold, glass-bead annealing, Metal Clay Veneer, china paints, dichroics, enamels, glass fusing, heat treating, jewellery, ceramics, porcelain, pottery, stoneware, and small-scale sagging and slumping.

The UK kiln is rated at 230V 1800W, so can use a regular mains socket. It's small enough to use in your home, school, college, craft workshop, ceramics studio, or course venue, as it only weighs about 34Kg.

The outer steel case measures 432mm x 508mm x 395mm, including the programmer housing and other hardware, but excluding the 50mm high base.

To comply with EU safety regulations, the kiln is fitted with a lid switch which cuts off power to the elements whenever the kiln is opened: an important safety feature included in the price.

The firebrick firing chamber measures 191mm x191mm x 229mm internally, and heats from all sides, with the fast-firing elements lying in grooves in the 64mm thick bricks.

The electronic display prompts for heating rate, target temperature, and hold time, making it easy to set up and re-use accurate drying, heating, holding, and cooling sequences.

There's a recommended kit, included in the price: one 178mm x 178mm x 15mm cordierite shelf, four 12mm shelf posts, and 450gm of glass separator.

There's an extra recommended kit, not included in the price: one 178mm x 178mm x 15mm shelf and four posts. You can choose 12mm, 25mm, or 50mm posts.

Depending on the material or process, and the sizes of your pieces, stacked shelves will hold more work, free up your time, and reduce the unit firing cost: so you might want more kits. This kiln has room for four.

The internet is packed full with inaccuracies: accidental or intentional. There are unsubstantiated claims that whatever is being sold is the best, the newest, or the cheapest, and it's being sold by the largest dealer or the premier distributor.

This comprehensive internet resource helps you choose the right kiln, and avoid an expensive mistake if, several weeks later, you discover new materials or processes, want to make larger pieces, or find a promising business niche.

So, why buy a Paragon Caldera from Cherry Heaven?

The Orton Sentry digital programmers allow you to set up multiple sequences, each one with multiple heating, holding, or cooling segments: so you can choose the heating and cooling rates, target temperatures, and hold times, save the sequences, and re-use them. There are no restrictive features such as single-sequence use or pre-set programmes.

Pre-set fixed programmes might seem to be an advantage. However, having experimented and diversified, many people fire materials, or combinations of materials, at different temperatures and for different times than are recommended. So pre-sets would soon become a serious limitation.

The heavy-gauge nickel-plated copper wiring has high-temperature glass-braided insulation. The thermocouple, which senses temperature inside the kiln, is protected with a high-nickel stainless-steel sheath for long life.

The Xpress series elements lie in pinless dropped-recessed grooves in the firebrick, and are quick, easy, and inexpensive to replace should they eventually fail.

It's widely believed that glass viewing-windows will cloud permanently or crack by about 925°C. The glass used in the Paragon Caldera, FireFly, SC, and Xpress series kilns has been time-tested at 1260°C.

Kilns from competing manufacturers typically have a separate programmer, a simpler programmer, or no programmer. They're smalller inside, don't get as hot, don't come with professional shelf kits, have out-dated features, use restrictive pre-set programmes, aren't in stock, or there are no spares. They're generally more expensive, especally as misleading first-sight prices often exclude a shelf kit, delivery, and VAT.

And, generally, there aren't any options and upgrades: left or right-hand doors, thicker firebricks, ceramic-fibre interiors, bead-annealing doors, viewing windows, extra peepholes or vents, 12-key programmers, mercury switches, electric kiln vents, auxilliary power outputs, RS232 or USB computer interfaces, and different shelf kits.

With some retailers, there wasn't a price list. With others, the same kilns were a lot more expensive. With some on-line order-forms, VAT and delivery were only evident after submitting all the personal and card details.

Here are a few facts that you can easily check for yourself, based on net-shop specifications and prices in June 2011 for Efco, Evenheat, and KilnCare kilns. However, buy a Paragon and, with the saving, you can treat yourself to a luxury five-star weekend break.

The Paragon Caldera-S is broadly similar to the Evenheat Hot Box and Evenheat Studio 8. However, the Caldera is 267% larger inside than the Hot Box and 154% larger than the Studio 8. It's also 308°C hotter, making it much more versatile: you get a ceramics and glass kiln instead of a glass kiln.

The Paragon Caldera-S kilns have the pyrometer mounted safely in the controller housing. The Evenheat kilns have an analogue pyrometer mounted on an external bracket: it looks a bit like an afterthought and is probably easily damaged.

The Paragon Caldera-A is broadly similar to the Evenheat Studio Pro. However, the Caldera is 154% larger inside than the Studio Pro and 308°C hotter, making it much more versatile. In November 2011, these Evenheat kilns were commercially invisible in the UK so I couldn't find any prices. And copy-kilns don't have Paragon's international, informed, and supportive user-base, or EU spares and repair centres.

The Paragon Caldera-A is broadly similar to the Skutt Fire Box 8, but 146% larger and 195°C hotter. Again, it's a true ceramics kiln.

The Paragon Caldera-S and the Caldera-A can both accept a separate removable layer called a collar, either as a plain collar, a collar with a bead-annealing door, or a collar wth an enamelling door, all of which increase the internal height by 110mm.

The Evenheat HotBox and Skutt FireBox don't have a lid-activated cut-off switch, so are illegal in the EU. It's also worth quoting Skutt: there's a risk of melting the elements if the kiln is not regularly monitored above 800°C.

The Caldera is large enough to accommodate the charcoal-filled stainless steel container needed to fire some makes of bronze clay and copperclay, both described further down this page.

Owners call it their Art Clay kiln, PMC kiln, metal-clay kiln, bead-annealing kiln, bead kiln, bronze-clay kiln, ceramic kiln, copper-clay kiln, dichroic-glass kiln, enamel kiln, enamelling kiln, glass kiln, glass-clay kiln, glass-fusing kiln, heat-treating kiln, jewellery kiln, jewelry kiln, lampwork kiln, mixed-media kiln, porcelain kiln, pottery kiln, silverclay kiln, small kiln, or studio kiln. This diversity is a good reflection of their popularity.

If you need help choosing or have a specific project, mail or call. However, all the kilns are described on their own pages.

Generally, programmable kilns work like this: as soon as the programmer's sequence starts, the kiln begins to heat up. The thermocouple tells the programmer the current internal temperature and, depending on the sequence you've chosen, the programmer turns the elements on or off to control the heating rate, maintain the target temperature, or control the cooling rate. When the sequence is complete, the kiln beeps, and the programme stops.

For safety, the programmer doesn't switch the full mains voltage. Instead it drives a relay, an electro-mechanical switch. The programmer uses a low voltage to activate the switch which turns the high voltage elements on or off.

When the target temperature is reached, the programmer switches the elements off. However, residual heat in the firing chamber allows the internal temperature to overshoot the target temperature briefly before starting to fall back.

This overshoot is more evident at low temperatures than at high temperatures. For example: 300°C will probably overshoot to 330°C whereas 800°C will probably only overshoot to 805°C before starting to fall back.

During the hold-time, with the elements still off, the temperature falls. When the programmer switches the elements back on, the firing chamber will initially absorb some of the new heat before the temperature recovers. The continual switching of the elements on and off causes the internal temperature to cycle around the target temperature.

Regardless of the thermocouple temperature, the actual temperature of your work will be slightly different, depending on its position on the kiln shelf, the vertical spacing of any stacked shelves, and its nearness to the elements, a lid, a door, a bead door, or a window. Learn to take it into account if you're working with temperature-critical materials or processes.

Remember that glass needs radiant heat and will fuse, sag, or slump better on one shelf at the bottom than between closely stacked shelves.

Kiln doors and lids are not meant to be a perfect fit otherwise, at high temperatures, there'd be no room for expansion and movement, and the door could stick and the ceramic-fibre or firebricks could crack.

All kilns smell a bit during the first few firings, just like a toaster or a fan heater. If you're worried about fumes, open a window.

Eventually, with normal use, kilns discolour slightly, inside and outside, and some firebricks might develop hairline cracks. Your kiln is a versatile, robust, red-hot tool: not an ornament.

Using your kiln successfully needs critical research and frequent tests, especially as things that work for your friends or teachers might not work in the same way for you. It's also very important to learn how to creatively use unexpected effects. So, keep a firing log:

Buy a durable notebook. Use a new page for every firing, and draw diagrams of the shelves, their vertical spacing, and the position of your work on the shelves. Along with your work, put a few scraps at different places on the shelves to learn how things change. Describe the material, the shape of your work, the firing cycle, and the end result.

A kiln log is vital if you're experimenting with temperature-sensitive materials, or working with coloured dichroic glasses, enamels, glazes, or paints, and a skilled artist will use the kiln log to advantage to re-create effects.

It'll be particularly useful if you have to repeat a commission, or you have a long holiday before returning to your studio.

If the kiln has a Sentry 12-key digital programmer, it can connect to your computer using a factory-fitted USB interface. ControlMaster software, included in the price, allows you to control and monitor the firing, and organise, analyse, print out, and save the data. If you want this option, make sure you order the USB interface.

There are two popular makes of silver clay: Art Clay made by Aida Chemical Industries and PMC made by Mitsubishi Materials Corporation, in Japan. They're both clay-like materials made of fine silver powder and water-soluble organic binders.

Art Clay Silver and PMC Silver, sometimes just called silver clay, metal clay, or precious-metal clay, are easy to fire: put your dried work on a kiln shelf and programme the temperature and hold-time.

As they're fired, the binders vapourise, releasing very small amounts of non-toxic carbon dioxide and water, and the metal powder sinters, leaving solid 999 silver: real metal, not something that just looks like metal.

Although Paragon kilns include a durable shelf kit so that you can start work straight away, several shelves can be stacked to make better use of your time and reduce the unit-cost of firing: so you might want more than one.

Although we chose to work with, sell, and provide classes in Art Clay, both makes fire in a similar way. So any kiln suitable for Art Clay will be just as good for PMC.

If you're currently using PMC, try Art Clay. There are differences in the feel, the shrinkage, the strength, the surface lustre, the product range, the pricing, and the general commercial setup if you're running a serious business.

Currently, in January 2012, 50 gms of PMC+ Silver Clay from the UK distributor costs about 37% more than Art Clay Silver Clay. If anyone would like to comment on this, let me know and provide a reference.

To learn more, use the links below the menu bar near the top of the page. You can buy ArtClay, bronzeclay, copperclay, glassclay, goldclay, and related products in the on-line shop.

There are three popular makes of bronze clay: Bronze Clay made by ClayMania, BronzClay made by Metal Adventures, and Prometheus Bronze ProClay made by Odak. They're all clay-like materials made of fine bronze powder and water-soluble organic binders. However, they're fired in different ways:

Prometheus Bronze Clay is easy to fire: wrap your dried work in kitchen tissue or ceramic cloth, put it on a kiln shelf, and programme the temperature and hold time. It can also be fired in charcoal.

Clay Mania Bronze Clay and MetalAdventures BronzClay fire in a special way. Fired normally, the surface would oxidise so, to minimize this, they're embedded in activated charcoal granules in a covered stainless steel container. Charcoal made from coconut shells produces a natural bronze colour, and charcoal made from coal produces a colourful range of patinas.

As they're fired, the binders vapourise, releasing very small amounts of non-toxic carbon dioxide and water, and the metal powder sinters, leaving solid bronze, an alloy of 89% copper and 11% tin: real metal, not something that just looks like metal.

The stainless steel container for the Paragon SC-2 measures 162mm x 176mm x 100mm, and holds 1 litre of charcoal. To fire larger pieces, or more pieces at the same time, you'll need a larger kiln, such as the Paragon Xpress E-12A. The container for the E-12A measures 265mm x 162mm x 152mm and holds 3 litres of charcoal.

The 1230°C firebrick E12A costs more than the 1095°C ceramic-fibre SC2. However, it's two and a half times larger than the SC-2 and is a versatile mixed-media kiln suited to continual high temperatures.

Particulates represent a health risk if they're breathed in, so wear a HEPA mask when cleaning out your kiln, mixing kiln wash, and working with charcoals, ceramic-fibre blocks, cloths, and papers. And, ideally, use protective glasses.

Although Paragon kilns include a durable shelf kit so that you can start work straight away, several shelves can be stacked to make better use of your time and reduce the unit-cost of firing: so you might want more than one.

I can't recommend one clay as being the best. There are differences in the feel, the firing, the shrinkage, the strength, and the surface patinas, so try them and experiment: they're not expensive.
However, as Prometheus Bronze Clay is easy to fire and costs less than the others, try it first? It comes as 100gm of soft clay in a packet, or 10gm of creamy clay in a syringe with three tips that you can cut or shape.

There's also Creative Bronze, which is almost certainly Prometheus Bronze Clay renamed. I'll leave it you to work out why ProBronze is £19.75 for 100gm with no delivery charge and Creative Bronze is £24.95 plus £4.95 shipping.

Currently, in January 2012, 100gms of Art Clay Silver Clay costs about 1100% more than Prometheus Bronze Clay and PMC+ Silver Clay costs at least 1370% more. If anyone would like to comment on this, let me know and provide a reference.

So, if you're still in the learning phase, you can try out ideas before possibly wasting your expensive silver clay. However, bronze is a beautiful metal so, as with many materials, you need to exploit its qualities and try to produce beautiful original pieces.

To learn more, use the links below the menu bar near the top of the page. You can buy ArtClay, bronzeclay, copperclay, glassclay, goldclay, and related products in the on-line shop.

There are four popular makes of copper clay: Art Clay Copper made by Aida Chemical Industries, Copper Clay made by ClayMania, CopprClay made by Metal Adventures, and Prometheus Copper ProClay made by Odak. They're all clay-like materials made of fine copper powder and water-soluble organic binders. However, they're fired in different ways:

Clay Mania Copper Clay and MetalAdventures CopprClay fire in a special way. Fired normally, the surface would oxidise so, to minimize this, they're embedded in activated charcoal granules in a covered stainless steel container. Charcoal made from coconut shells produces a natural copper colour.

Art Clay Copper is easy to fire: put your dried work on a kiln shelf, and programme the temperature and hold time. In most kilns, several shelves can be stacked to make better use of your time: so you might want more than one.

Prometheus Copper Clay is easy to fire: wrap your dried work in kitchen tissue or ceramic cloth, put it on a kiln shelf, and programme the temperature and hold time. It can also be fired in charcoal.

As they're fired, the binders vapourise, releasing very small amounts of non-toxic carbon dioxide and water, and the metal powder sinters, leaving solid copper: real metal, not something that just looks like metal.

The stainless steel container for the Paragon SC-2 measures 162mm x 176mm x 100mm, and holds 1 litre of charcoal. To fire larger pieces, or more pieces at the same time, you'll need a larger kiln, such as the Paragon Xpress E-12A. The container for the E-12A measures 265mm x 162mm x 152mm and holds 3 litres of charcoal.

The 1230°C firebrick E12A costs more than the 1095°C ceramic-fibre SC2. However, it's two and a half times larger than the SC-2 and is a versatile mixed-media kiln suited to continual high temperatures.

Particulates represent a health risk if they're breathed in, so wear a HEPA mask when cleaning out your kiln, mixing kiln wash, and working with charcoals, ceramic-fibre blocks, cloths, and papers. And, ideally, use protective glasses.

Although Paragon kilns include a durable shelf kit so that you can start work straight away, several shelves can be stacked to make better use of your time and reduce the unit-cost of firing: so you might want more than one.

I can't recommend one clay as being the best. There are differences in the feel, the firing, the shrinkage, the strength, and the surface patinas, so try them and experiment: they're not expensive.
However, as Prometheus Copper Clay is easy to fire and costs less than the others, try it first? It comes as 100gm of soft clay in a packet, or 10gm of creamy clay in a syringe with three tips that you can cut or shape.

There's also Creative Copper, which is almost certainly Prometheus Copper Clay renamed. I'll leave it you to work out why ProCopper is £19.75 for 100gm with no delivery charge and Creative Copper is £24.95 plus £4.95 shipping.

Currently, in January 2012, 100gms of Art Clay Silver Clay costs about 1100% more than Prometheus Copper Clay and PMC+ Silver Clay costs at least 1370% more. If anyone would like to comment on this, let me know and provide a reference.

So, if you're still in the learning phase, you can try out ideas before possibly wasting your expensive silver clay. However, bronze is a beautiful metal so, as with many materials, you need to exploit its qualities and try to produce beautiful original pieces.

To learn more, use the links below the menu bar near the top of the page. You can buy ArtClay, bronzeclay, copperclay, glassclay, goldclay, and related products in the on-line shop.

GlasClay is made by ClayMania in vibrant colours, based on glasses from Bullseye and Oruboros. It's a clay-like material made of fine glass powder and water-soluble organic binders. It's sold as a box of twelve colours in 12gm pots.

The colours in the table below are a rough guide, and the clay powder, mixed powders, fused glass, and re-fused glass will not all look the same. They're all COE90: read this pop-up.

As it's fired, the binders vapourise, releasing very small amounts of non-toxic carbon dioxide and water, and the glass powder fuses, leaving solid glass: real glass, not something that just looks like glass.

GlasClay is easy to fire: put your dried pieces on some ceramic shelf-paper on a kiln shelf and programme the temperature and hold time.

GlasClay can be shaped easily. You can make three-dimensional objects and free yourself from the constraint of working with flat glass. The size is only determined by the support you can give it. Perhaps the most exciting opportunity is to make your own beads without a torch.

The firing temperature and time are important: glass clays have to fuse, not melt. There's a difference between fusing and melting: During fusing, the binder in the glass clay vapourises and the glass powder particles bond to make solid glass. During melting, the glass powder particles liquify and lose their original clay-shape.

Particulates represent a health risk if they're breathed in, so wear a HEPA mask when cleaning out your kiln, mixing kiln wash, and working with charcoals, ceramic-fibre blocks, cloths, and papers. And, ideally, use protective glasses.

Although Paragon kilns include a durable shelf kit so that you can start work straight away, several shelves can be stacked to make better use of your time and reduce the unit-cost of firing: so you might want more than one.

To learn more, use the links below the menu bar near the top of the page. You can buy ArtClay, bronzeclay, copperclay, glassclay, goldclay, and related products in the on-line shop.

There are two popular makes of gold clay: Art Clay made by Aida Chemical Industries and PMC made by Mitsubishi Materials Corporation, in Japan. They're both clay-like materials made of fine gold powder and water-soluble organic binders.

Art Clay Gold and PMC Gold, sometimes just called gold clay, metal clay, or precious-metal clay, are easy to fire: put your dried work on a kiln shelf and programme the temperature and hold-time.

As they're fired, the binders vapourise, releasing very small amounts of non-toxic carbon dioxide and water, and the metal powder sinters, leaving solid 22 carat gold: real metal, not something that just looks like metal.

Although Paragon kilns include a durable shelf kit so that you can start work straight away, several shelves can be stacked to make better use of your time and reduce the unit-cost of firing: so you might want more than one.

Although we chose to work with, sell, and provide classes in Art Clay, both makes fire in a similar way. So any kiln suitable for Art Clay will be just as good for PMC.

If you're currently using PMC, try Art Clay. There are differences in the feel, the shrinkage, the strength, the surface lustre, the product range, the pricing, and the general commercial setup if you're running a serious business.

Currently, in January 2012, 50 gms of PMC Gold Clay from the UK distributor costs about 60% more than Art Clay Gold Clay. If anyone would like to comment on this, let me know and provide a reference.

To learn more, use the links below the menu bar near the top of the page. You can buy ArtClay, bronzeclay, copperclay, glassclay, goldclay, and related products in the on-line shop.

This internet resource is provided by Cherry Heaven, an international distributor, on-line shop, and support centre for electric kilns. It's not a bead, ceramics, crafts, glass, or metal-clay home-business, selling a few kilns to a market niche.

As it's on-line, there isn't a paper catalogue or a price list. However, you can mail or call a technician about kilns, power supplies, public area safety, a special project, business ideas, home diagnostics, repairs, or reselling opportunities.

Cherry Heaven is a shop in Corfe Castle village, in Dorset, South-West England. The surrounding countryside includes green farmland, dramatic cliffs, pretty cottages, historic buildings, sandy beaches, protected coves, open heathland, hill-top panoramic views, and peaceful villages. And lively seaside resorts. To look at some photos, use the dorset link.

Cherry Heaven is an EU distributor for Paragon Kilns, and has been commended for an outstanding performance as one of Paragon's top-selling distributors over 2007 to : a pleasing outcome since the UK is only one third the area of Texas and one fortieth the area of the US.

Paragon Industries started as a family business in 1948. It's now the world's leading manufacturer of electric kilns and furnaces, and has built over 420,000. The 4,800 square metre site, in Mesquite, Texas, USA, has over 70 full-time staff.

During manufacture, every kiln is checked at every stage by a technician and signed-off before shipping. They're simply but robustly engineered, and you're buying a comprehensive, versatile, safe, low-cost kiln: a kiln with a future.

Paragon kilns conform to the demanding UL 499 standard in the US, and are CE Marked for the EU. Paragon is Greek for Model Of Perfection.

The Kitiki Studio provides a comprehensive Art Clay educational programme, as classes, masterclasses, workshops, and Art Clay Level 1 and Level 2 certification courses. If you're interested, mail or call.

The on-line shop link is below the menu bar near the top of the page, on the right: you won't have to create an account, register, log on, look up your membership number, remember a password, sign up, join a club, or agree to be emailed. And the total won't be more than you expected because VAT and UK-mainland delivery are included.