The most popular choices for glass work are the Paragon Fusion, GL, and Pearl series kilns, although you can use any kiln that heats to 925°C. Before looking at the choices in detail, here's a brief summary of the material:

The main component of glass is silicon dioxide, often called silica: found naturally and plentifully as sand. When it melts, at around 1700°C, it's like syrup on a cold day. When it cools, it forms a rigid and brittle glass called quartz glass.

To lower the melting point, and the cost of melting, chemicals are added: typically sodium carbonate and calcium oxide. Other chemicals, and different heating and cooling processes, can produce a range of mechanical properties and colours.

Chemically, glass is classed as an amorphous solid: not a liquid, as is widely believed. As it's heated, it becomes softer allowing it to be blown, moulded, poured, pressed, coated, decorated, engraved, or heat-treated.

A form of glass occurs naturally within the mouth of a volcano when the intense heat of an eruption melts sand to form Obsidian, a hard black glassy type of stone.

If two or more pieces of glass in contact are heated, they begin to soften and fuse together. With careful heating and cooling, the separate pieces of glass become one.

If glass is put on a mould and heated, it begins to soften and collapse, or sag, onto the mould: a common technique for making bowls and plates.

Sagging and slumping are often thought of as being the same. Correctly: during sagging, heated glass, supported at its edges, sags down in the middle to conform to a mould; during slumping, heated glass, supported at its middle, slumps down at its edges to conform to a mould.

During annealing, fabrication stresses are relieved as the molecules cool and arrange themselves into a regular stable matrix. Successful annealing is the key to creating glasswork that will remain attractive and durable.

Dichroic glass has two different colours: a transmitted colour and a reflective colour, both of which change depending on the angle of view. For example blue-red will be blue in transmission and red in reflection.

During manufacture, quartz and metal oxides are vapourized onto the surface of the glass using a vacuum deposition process, forming a multi-layer crystal structure.

All the kilns described on this page have two diagrams: front and side views. To look at larger photos, hold your mouse over the zoom buttons below. The photos are 480px x 360px and about 30KB so, if you're not on a fast internet connection, they'll take a short while to download.

Paragon GL 18ADTSD.

Paragon GL 22ADTSD.

Paragon GL 24ADTSD.

Paragon GL 44ADTSD.

Paragon GL64 ADTSD.

Paragon Ovation.

Whilst comparing kilns, there are important considerations: the kiln's versatility, the overall size and weight, the power supply, the maximum temperature, the firing chamber floor area and height, the firing chamber material, and the price.

As with any device you buy, a kiln is not designed to be run full-on all the time. So, if you need to fire at 1095°C for a long time, buy a 1290°C kiln, not a 1095°C kiln.

Any kiln that heats up to 925°C can be used for glass work: the only kilns that don't are the two dedicated glass-bead annealing kilns, the 650°C BlueBird and the 815°C EZ Beader.

The Caldera series, the Home Artist, the SC series, and the Xpress series, are widely used for making glass jewellery, annealing glass beads, enamelling, firing metal clays, and small-scale glass fusing. However, they're not large enough for most commercial glass work.

The Fusion 6, 7, 8, and 10 kilns are all round-ish, top-opening, firebrick kilns, designed for glass work. The cylindrical design is simple to make, and costs less to ship, so the series is very popular with glass artists.

A 13A Fusion 8, smaller and with fewer elements, has been promoted to an innocent market: it's not recommended. It would take too long to heat up, might not reach its maximum temperature, and the temperature would change with local voltage variations.

The GL 18, 22, and 24 kilns are all square, front-loading, firebrick kilns, designed for glass work. The front-loading square shape is more appropriate for some type of glass work. They all need a separate power supply, not a 13A socket.
The AD models heat from the top. The ADTSD models heat from the top, both sides, the back, and the front, and give the best possible heat distribution.

The larger GL 44 and 64 kilns are both rectangular, top-opening, firebrick kilns, designed for glass work. They're usually used for flat panels, curved windows, and architectural features. They all need a separate power supply, not a 13A socket.
The AD models heat from the top. The ADTSD models heat from the top, both sides, the back, and the front, and give the best possible heat distribution.

The Pearl 18, 22, and 44 kilns are all rectangular, top-opening, firebrick kilns, designed for glass work. The clamshell design makes it easy to arrange your work before closing the lid. They all need a separate power supply, not a 13A socket.

The Fusion, GL, and Pearl series are all 925°C kilns: they're not hot enough for ceramics, porcelain, pottery, and stoneware.

The versatile 1290°C Janus ceramics kilns can fire glass and pottery: for glass, use the top and middle-side elements; for pottery, use all the side elements. The Janus 1613, 23, and 27 look similar to the Fusion 7, 8, and 10. The Janus 24 looks similar to the Gl 24.

You can't use the US model numbers as guides to the internal sizes of the kilns. They might have historical significance but now, often, don't mean anything useful.
The US model names used: A for painted finish; D for digital programmer; E for enamelling front-loading; GL for glass, Q for ceramic front-loading; SC for small ceramic-fibre, not silverclay; TNF for touch n fire; V for vista, or window; and Xpress for digital programmer.

The UK naming convention has been tidied up, and uses B for a bead-annealing door, W for a glass viewing-window, and BW for both. However, to help internet searches, we've had to include occasional minor variations. For example, the SC-2B is sometimes called an SC2B.

Paragon programmers do not have pre-set programmes: you can easily set up and re-use your own sequences: mixes of heating, holding, and cooling segments which will run automatically and then stop. Although pre-sets might seem useful, you won't be able to experiment, or try or use other materials, combinations, or firing sequences. There are no restrictive features such as single-sequence use or material-specific programmes.

The prices include the recommended shelf kit and the legally-necessary lid or door safety switch, where appropriate, and UK mainland delivery. To look at the prices, use the shop link below the menu bar near the top of the page.

GL series front-loading kilns come in three sizes, 18, 22, and 24, representing the internal width in inches. They're all 925°C, square, front-loading kilns, with easy-to-use, ramp-hold, Sentry Xpress 3-key digital programmers.

The AD models heat from the top. The ADTSD models heat from the top, both sides, the back, and the door, and give the best possible heat distribution. They all need a separate power supply, not a 13A socket.

If you compare the GL18 and GL24 series with similar kilns from other manufacturers, such as the KilnCare Spitfire and KilnCare Firecracker, they cost a lot less.

The Paragon GL-18ADTSD is ideal for glass fusing, sagging, and slumping. It's a 925°C, four-sided, square, front-loading kiln, with an easy-to-use, ramp-hold, Sentry Xpress 12-key digital programmer.

The UK kiln is rated at 230V 4800W, so needs a separate 30A power supply. To comply with EU safety regulations, it's fitted with an additional switch that cuts off the power when the door is opened. It needs a strong table as it weighs about 144Kg.

The outer steel case measures 877mm x 712mm x 648mm, including the programmer housing and other hardware, and has two wide-view peepholes in one of the sides.

The firebrick firing chamber measures measures 458mm x 458mm x 331mm internally, and heats from the top, both sides, the back, and the door, with the fast-firing elements laying in grooves in the 76mm 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. To learn more about the programmer, use the start link below the menu bar, then choose programmers.

It's very important to understand what the shelf kit consists of, why you might need a different one, and why you might need more than one:

The recommended furniture kit, included in the price, consists of one 406mm x 356mm x 15mm cordierite shelf, four 25mm x 25mm x 12mm posts, and a bag of glass separator.

Cordierite is a magnesium aluminium silicate that resists thermal distortion and fracture. A thick shelf, on posts, heats and cools evenly: particularly important for glass work.

Cordierite is brittle: if you drop the shelf, it'll break. It's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses. You can buy extra shelf kits in the on-line shop.

Depending on the sizes of your pieces and the number of pieces you want to fire, two shelves can be stacked to make better use of your time: so you may want more than one furniture kit. However, remember that glass needs radiant heat and is better fired on one shelf, not between stacked shelves.

For enamelling and glass fusing, you'll need to put kiln paper on the shelf to stop anything sticking: it's simpler and cleaner to use than glass separator. You can buy shelf paper in the on-line shop.

The GL-18AD only heats from the top, but the cost-saving has to be offset against the different firing options. Otherwise it's the same as the GL-18ADTSD.

The Paragon GL-22ADTSD looks similar to the GL-18ADTSD, but has a firing chamber volume 1.22 times larger than that of the GL-18ADTSD. The UK kiln is rated at 230V 11000W, so needs a separate 60A power supply. It needs a strong table as it weighs about 152Kg.

The outer steel case measures 953mm x 762mm x 585mm, including the programmer housing and other hardware, and has two wide-view peepholes in one of the sides.

The firebrick firing chamber measures measures 534mm x 534mm x 337mm internally, and heats from the top, both sides, the back, and the door.

It's very important to understand what the shelf kit consists of, why you might need a different one, and why you might need more than one:

The recommended furniture kit, included in the price, consists of one 508mm x 508mm x 15mm cordierite shelf, four 25mm x 25mm x 12mm posts, and a bag of glass separator.

Cordierite is a magnesium aluminium silicate that resists thermal distortion and fracture. A thick shelf, on posts, heats and cools evenly: particularly important for glass work.

Cordierite is brittle: if you drop the shelf, it'll break. It's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses. You can buy extra shelf kits in the on-line shop.

Depending on the sizes of your pieces and the number of pieces you want to fire, two shelves can be stacked to make better use of your time: so you may want more than one furniture kit. However, remember that glass needs radiant heat and is better fired on one shelf, not between stacked shelves.

For enamelling and glass fusing, you'll need to put kiln paper on the shelf to stop anything sticking: it's simpler and cleaner to use than glass separator. You can buy shelf paper in the on-line shop.

The GL-22AD only heats from the top, but the cost-saving has to be offset against the different firing options. Otherwise it's the same as the GL-22ADTSD, described above.

The Paragon GL-24ADTSD, the largest of the GL front-loading series, looks similar to the GL-18ADTSD, but has a firing chamber volume 1.91 times larger than that of the GL-18ADTSD. The UK kiln is rated at 230V 10 800W, so needs a separate 60A power supply. It needs a strong table as it weighs about 181Kg.

The outer steel case measures 1029mm x 813mm x 750mm, including the programmer housing and other hardware, and has two wide-view peepholes in one of the sides.

The firebrick firing chamber measures measures 610mm x 572mm x 381mm internally, and heats from the top, both sides, the back, and the door.

It's very important to understand what the shelf kit consists of, why you might need a different one, and why you might need more than one:

The recommended furniture kit, included in the price, consists of one 559mm x 559mm x 25mm cordierite shelf, four 25mm x 25mm x 12mm posts, and a bag of glass separator.

Cordierite is a magnesium aluminium silicate that resists thermal distortion and fracture. A thick shelf, on posts, heats and cools evenly: particularly important for glass work.

Cordierite is brittle: if you drop the shelf, it'll break. It's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses. You can buy extra shelf kits in the on-line shop.

Depending on the sizes of your pieces and the number of pieces you want to fire, two shelves can be stacked to make better use of your time: so you may want more than one furniture kit. However, remember that glass needs radiant heat and is better fired on one shelf, not between stacked shelves.

For enamelling and glass fusing, you'll need to put kiln paper on the shelf to stop anything sticking: it's simpler and cleaner to use than glass separator. You can buy shelf paper in the on-line shop.

The GL-24AD only heats from the top, but the cost-saving has to be offset against the different firing options. Otherwise it's the same as the GL-24ADTSD, described above.

GL series top-opening kilns come in two sizes, 44 and 64, representing the internal width in inches. They're all 925°C, four-sided, rectangular, top-opening kilns, with easy-to-use, ramp-hold, Sentry Xpress 3-key digital programmers.

The AD models heat from the top. The ADTS models heat from the top and all sides, and give the best possible heat distribution. They all need a separate power supply, not a 13A socket.

The base can accept an optional Orton Vent Master kiln vent: to learn more, use the start link below the menu bar, then choose accessories, then scroll down.

GL series top-opening kilns can also be used for quantity production for retail using Art Clay and PMC silver clays, china painting, dichroics, and enamels. However, jewellery artists usually prefer smaller kilns that heat and cool more quickly, such as those in the SC and Xpress series.

The GL-44ADTS is ideal for flat panels, curved windows, architectural features, stained glass designs, fusing, sagging, slumping, lampshades, and quantity production for retail. It's a 925°C, four-sided, rectangular, flat-bed, top-opening kiln, with an easy-to-use, ramp-hold, Sentry Xpress 12-key digital programmer.

The UK kiln is rated at 230V 11500W, so needs a separate 50A power supply. To comply with EU safety regulations, it's fitted with an additional switch that cuts off the power when the lid is opened. It needs a strong floor as it weighs about 403Kg.

The kiln measures 1423mm x 712mm x 1016mm, including the programmer housing, six legs, and other hardware, and has an easy-lift lid, and four wide-view peepholes in the front.

The firing chamber measures 1118mm x 559mm x 407mm internally, and heats from the top and all sides, with the fast-firing elements laying in grooves in the 102mm thick top ceramic fibre and the 64mm thick side firebricks.

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. To learn more about the programmer, use the start link below the menu bar, then choose programmers.

It's very important to understand what the shelf kit consists of, why you might need a different one, and why you might need more than one:

The recommended furniture kit, included in the price, consists of two adjacent 508mm x 508mm x 15mm cordierite shelves, eight 25mm x 25mm x 12mm posts, and a bag of glass separator.

Cordierite is a magnesium aluminium silicate that resists thermal distortion and fracture. A thick shelf, on posts, heats and cools evenly: particularly important for glass work.

Cordierite is brittle: if you drop the shelf, it'll break. It's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses. You can buy extra shelf kits in the on-line shop.

Depending on the sizes of your pieces and the number of pieces you want to fire, two shelves can be stacked to make better use of your time: so you may want more than one furniture kit. However, remember that glass needs radiant heat and is better fired on one shelf, not between stacked shelves.

For enamelling and glass fusing, you'll need to put kiln paper on the shelf to stop anything sticking: it's simpler and cleaner to use than glass separator. You can buy shelf paper in the on-line shop.

The GL-44AD only heats from the top, but the cost-saving has to be offset against the different firing options. Otherwise it's the same as the GL-44ADTS.

The GL-64ADTS is ideal for flat panels, curved windows, architectural features, stained glass designs, fusing, sagging, slumping, lampshades, and quantity production for retail. It's a 925°C, four-sided, rectangular, flat-bed, top-opening kiln, with an easy-to-use, ramp-hold, Sentry Xpress 12-key digital programmer.

The UK kiln is rated at 230V 16500W, so needs a separate 75A power supply. To comply with EU safety regulations, it's fitted with an additional switch that cuts off the power when the lid is opened. It needs a strong floor as it weighs about 500Kg.

The kiln measures 1931mm x 712mm x 1016mm, including the programmer housing, six legs, and other hardware, and has an easy-lift lid, and eight wide-view peepholes in the front.

The firebrick firing chamber measures 1626mm x 559mm x 407mm internally, and heats from the top and all sides, with the fast-firing elements laying in grooves in the 102mm thick top ceramic fibre and the 64mm thick side firebricks.

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. To learn more about the programmer, use the start link below the menu bar, then choose programmers.

It's very important to understand what the shelf kit consists of, why you might need a different one, and why you might need more than one:

The recommended furniture kit, included in the price, consists of three adjacent 508mm x 508mm x 15mm cordierite shelves, twelve 25mm x 25mm x 25mm posts, and a bag of glass separator.

Cordierite is a magnesium aluminium silicate that resists thermal distortion and fracture. A thick shelf, on posts, heats and cools evenly: particularly important for glass work.

Cordierite is brittle: if you drop the shelf, it'll break. It's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses. You can buy extra shelf kits in the on-line shop.

Depending on the sizes of your pieces and the number of pieces you want to fire, two shelves can be stacked to make better use of your time: so you may want more than one furniture kit. However, remember that glass needs radiant heat and is better fired on one shelf, not between stacked shelves.

For enamelling and glass fusing, you'll need to put kiln paper on the shelf to stop anything sticking: it's simpler and cleaner to use than glass separator. You can buy shelf paper in the on-line shop.

The GL-64AD only heats from the top, but the cost-saving has to be offset against the different firing options. Otherwise it's the same as the GL-64ADTS.

To learn more about table-top kilns that can use a regular mains socket, such as the UltraLite Kiln, the Kitiki Mini-Kiln, and the Paragon BlueBird, Caldera, FireFly, Fusion 6, Fusion 7, Home Artist, SC-2, SC-3, and Xpress, transfer to Electric Kilns, using the Electric Kilns link above the menu bar near the top of the page.

The kiln prices include the recommended shelf kit, and the legally-necessary lid or door safety switch where appropriate.

The on-line shop includes Paragon Kilns, BullsEye ThinFire kiln paper, ceramic blocks, ceramic cloths, digital pyrometers, reminder-timers, fire extinguishers, glare-resistant glasses, heat-resistant gloves, kiln shelves, kiln tables, and other tools and accessories. Alternatively, visit the Cherry Heaven Shop in Corfe Castle village.

Cherry Heaven is an EU distributor for Paragon Kilns made in the US, Advance Kilns made in Canada, Efco Kilns made in Germany, Kitiki Mini-Kilns made in Turkey, and UltraLite Kilns made in the US.

Cherry Heaven is a UK distributor for Art Clay made by Aida Chemical Industries in Japan and BronzClay made in the US, and an EU distributor for AccentGold For Silver paint and Metal Clay Veneer, both made in the US.