|the paragon dragon ceramics kiln||smaller kilns at electrickilns.co.uk or tumblers at electrictumblers.co.uk|
The Paragon Dragon-24 kiln is generally used for ceramics, earthenware, glass, porcelain, pottery, and raku. It's a 1290°C furnace with a digital programmer, in Paragon blue, or customised berry, black, jade, navy, pink, purple, or turquoise. Learn all about the Paragon Dragon kiln on this page.
The Sentry 12-key programmer can be upraded to a Sentinel Touch Screen. Both have advanced and time-saving features, including optional automatic control over an electric kiln vent, a gas injection system, and a USB computer interface.
For prices, use the shop link below the menu bar near the top-right of any page. They're for UK-EU voltage, CE-marked, TUV tested, and CL and CSA approved kilns, with safety switches, and include comprehensive manuals, and UK VAT. You can start work straight away.
|THE PARAGON DRAGON-24: PHOTOS|
To look at the pop-up photos, hold your mouse over the zoom buttons below: you don't need to click.
Paragon Dragon-24 Ceramics Kiln.
Paragon Dragon-24 Ceramics Kiln.
Paragon Sentry Digital Programmer.
Paragon Sentinel Touch-Screen Digital Programmer.
Lauscha By Carrie Fertig.
|STAY ON THIS RESOURCE, OR SWITCH TO ANOTHER?|
For your convenience, I've separated all the kilns into two very general groups on two separate internet resources, although there's cross-over. If you want to switch resources, use the links above the menu bar near the top of the page.
Electric Kilns is generally for smaller plug-in table-top kilns usually used for small-scale work such as annealing beads, Art Clay metal clays, dichroics, enamels, glass fusing, jewellery, lampwork, PMC silver clay, porcelain, and vitrigraph.
Paragon Kilns is generally for larger wired-in floor-standing or table-top kilns usually used for business-scale work such as annealing, casting, ceramics, earthenware, glass panels, heat treating, making knives, porcelain, pottery, and raku.
After looking at the kiln in detail, I'll introduce the appropriate accessories, options, and upgrades.
|THE PARAGON DRAGON-24||CASTING, CERAMICS, GLASS, PORCELAIN, POTTERY, AND STONEWARE|
The Paragon Dragon is a deluxe, professional, 1290°C, four-sided, front-opening, floor-standing, firebrick furnace, with a cone-fire ramp-hold, Sentry 12-key digital programmer. Choose Paragon black, or customised berry, blue, jade, navy, pink, purple, or turquoise. Customised kilns are made to order, so can't be returned if the colour isn't exactly the same as in the photo.
It's ideal for your arts centre, college, course venue, engineering works, glass studio, knife-making workshop, laboratory, machine shop, dental or medical laboratory, metalwork business, pottery studio, school, technical facility, or university.
Use it for firing ceramics, earthenware, porcelain, pottery, and stoneware, glass annealing, bisqueware, ceramic art, china painting, crucible glass work, applying decals, doll making, fire polishing, glass art, glass fusing, sagging, and slumping, forming glass panels, heat treating, making knives, laboratory testing, lampwork, lost-wax casting, mixing custom glass colours, pâte de verre, raku, staining glass, hardening and tempering blades, cutters, dies, and tools, and many other materials and processes.
The UK kiln is rated at 230V 16500W, so it needs a wired-in 75A 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 weighs about 411Kg.
The outer steel case measures 1113mm x 998mm x 1143mm high, including the programmer housing and other hardware. The 610mm high stand is an optional separate item. The door opens wide on an 18mm diameter hinge post with sealed bearings, and has two spring-loaded catches. There are two peepholes in one side. The control box hinges down for easy maintenance.
The firebrick firing chamber measures 610mm x 610mm x 686mm high internally, and heats from the sides and back, with the fast-firing proportional elements in grooves in the 76mm thick bricks. Behind the bricks is 25mm of ceramic insulation. The floor is made of 114mm thick bricks. It has a K-type long-life thermocouple, three long-life mercury relays, and a set of fuses.
The programmer's electronic display prompts for heating rates, target temperatures, and hold times, making it easy to set up and re-use accurate heating, holding, and cooling sequences.
The accessories, options, and upgrades for this kiln are in the on-line shop:
a berry, blue, jade, navy, pink, purple, or turquoise respray: normally black
stainless steel finish
door safety option
610mm, 459mm, or 204mm stands, with or without castors
a gas injection flow meter with a controlling solenoid
an electric kiln vent: factory fitted at the bottom
an auxiliary power output for automatic vent control: factory fitted
a USB computer interface: factory fitted
an S-type three-zone thermocouple: factory fitted
stacking shelf kits and shelf paper
ceramic fibre cloth
HEPA dust mask
clear protective glasses
And finally, my opinion.
The Paragon Dragon is a fully programmable, deluxe, professional-quality furnace for every kind of ceramic and glass work, so it's ideal for commercial studios. The Sentry 12-key programmer allows you to add automated gas injection, a controllable electric vent, and a USB programmer-to-computer interface.
The thick insulation saves energy and lengthens the cooling period making it easier to control glazes.
|THE PARAGON DRAGON KILN FURNITURE|
There's a recommended kit, not included in the price: one durable 558mm x 558mm x 25mm cordierite shelf, four durable 558mm x 279mm x 25mm half-shelves, 24 assorted-height posts, and 450gms of kiln wash.
There's an alternative basic kit, not included in the price: one durable 558mm x 558mm x 25mm cordierite shelf, four posts, and 450gms of kiln wash.
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 the whole kit rather than just one shelf.
The remaining sections are about digital programmers, options, upgrades, materials, and processes. Unless you're already successfully using a kiln, they're recommended reading.
Cherry Heaven has been a Paragon distributor since 2002, and commended every year for outstanding performance. Paragon kilns are good value: buy Paragons and you could save enough to treat yourself to a luxury five-star weekend break.
Anyone can buy a few kilns to resell and call themselves a specialist, but a distributor understands all the kilns, options, and upgrades, will stock spares, offer free competent technical support, can help you repair your kiln, provide on-line repair videos, has a repair workshop, and can access Paragon's international, informed, and supportive user-base.
If you need help, you can mail an experienced technician or call . Alternatively, to learn more about how your kiln works, use the help link below the menu bar near the top of the page.
|WHY BUY A PARAGON DRAGON?|
The internet, like any other unchecked resource, is open to 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.
With some retailers, misleading first-sight prices often exclude a digital programmer, a pro shelf kit, delivery, and VAT. With others, there isn't a price list so, to discover the actual cost, you have to set up an account: or call. With some on-line order forms, VAT and delivery were only evident after submitting all the personal and card details.
With others, exactly the same kilns were a lot more expensive. As an example, in October 2014, one supplier assured you that their prices were the cheapest in the UK. Except their SC2 was £134 more than it was here.
Cherry Heaven internet resources will help you choose the right kiln, and avoid an expensive mistake: especially if, later, you discover new materials or processes, win a challenging commission, want to make larger pieces, decide to run courses, or find a promising business niche. There's a lot to read, so it's up to you. Or you can just mail or call.
So, why buy a Paragon Dragon? Let's start with the programmer:
The Paragon Sentry 12-key digital programmer allows you to set up several firing sequences, each one with up to eighteen heating, holding, or cooling segments. You can choose the heating and cooling rates, target temperatures, and hold times, save the sequences, and re-use them. The programmer's cone-fire mode, up to cone 10, will simplify your work with ceramics.
It's built in, so you don't need a separate box with a cable, a separate thermocouple with a cable, and a separate stand: more stuff on your worktop. And, for temperature consistency, the built-in thermocouple is always in the same position.
There are no restrictive features such as single-sequence use or pre-set programmes. Fixed programmes might seem to be an advantage. However, having diversified and experimented, most people fire materials, or combinations of materials, at different temperatures and for different times than are recommended.
The programmer is easy to use: far easier than a central heating programmer. Here's a Cherry Heaven TV programme about setting a ramp-hold sequence. The ramp is the part where the temperature increases until it reaches the target temperature: the hold is the part where the temperature stays the same. Of course, UK-EU programmers will be in degrees Celsius.
Cherry Heaven TV provides on-line radio and television programmes using the Cherry Heaven Player. To play, pause, or stop the player, or adjust the volume, click the controls or, whilst it's playing, drag the time-line slider to a new position.
Now, the general construction:
The fast-firing heavy-guage elements lie in pinless dropped-recessed grooves in the 114mm thick bricks.
To comply with EU safety regulations, the kilns are 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.
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.
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.
In the unlikely event that your kiln develops a fault, it's reassuring to know that basic checks, adjustments, and repairs are quick and easy and need little more than a screwdriver and a pair of pliers. If you need help, an engineer can guide you on the phone. And the Paragon PMT series all have a two-year warranty. Alternatively, we can repair your kiln in our workshop at Cherry Heaven.
You can watch on-line service videos: use the main-menu link below the menu bar near the top of the page, then choose tee-vee, then choose from the guide. There's also an extensive support page: use the main-menu link, then choose help.
|MAKING A CHOICE|
To help you make a choice, there are four important things to consider: the maximum temperature, the internal size, the type of door or lid, and will it plug in to a regular socket.
If you're researching high-temperature kilns, there are several others to look at:
If you want a 1290°C kiln, look at the Janus series or the TNF series. If you don't need 1290°C, look at the 925°C glass kilns: the CS series, Fusion series, and Pearl series.
|VERSION||DESCRIPTION||MAX °C||POWER W||WEIGHT KG||FIRING CHAMBER||INTERIOR SIZE MM|
|Janus 1613||8-sided top-opening||1290||4800||90||firebrick||419 x 337|
|TNF 1613-3||8-sided top-opening||1290||6400||78||firebrick||419 x 317|
|Dragon-24||4-sided front-opening||1290||16500||411||firebrick||343 x 375|
|Vulcan||8-sided top-opening||1290||3950||109||firebrick||343 x 375|
The Orton-Paragon digital programmers allow you to set up multiple sequences, each one with multiple heating, holding, or cooling segments: you can choose the heating rates, target temperatures, hold times, and cooling rates, save the sequences, and re-use them.
There are no restrictive pre-set programmes. Pre-sets might seem to be an advantage. However, having experimented and diversified, most people fire materials, or combinations of materials, at different temperatures and for different times than are recommended.
For help, or in the unlikely event of a fault, you can mail or call an engineer in the UK. However, home checks, adjustments, and repairs are quick and easy, needing little more than a screwdriver, and you can watch on-line videos. Alternatively, we can repair the kiln in our workshop at Cherry Heaven.
The kilns can accept an optional Orton Vent Master kiln vent: to learn more, use the main-menu link below the menu bar, then choose accessories, then scroll down.
The Dragon kiln can be made for 200V, 208V, or 240V single phase or three phase, and 480V three phase. If you're interested, mail or call.
The Dragon heats from the sides and the back. The four elements are in pinless grooves in the firebrick, an important safety feature. However, never get careless: kilns are very hot and connected to the mains.
Owners call their Dragon a bisque kiln, bisqueware kiln, ceramics kiln, clay kiln, crucible kiln, earthenware kiln, greenware kiln, mixed media kiln, porcelain kiln, pottery kiln, raku kiln, or stoneware kiln. This diversity is a good reflection of its popularity.
They're popular with ceramic cafes, commercial studios, and pottery workshops as 1290°C is the highest temperature rating for regular kilns: above that, the materials and construction have to change, leading to much higher costs.
|KILN FURNITURE: A GENERAL INTRODUCTION||IMPORTANT|
Most kilns have a recommended furniture kit. Delivery companies have a low rate for parcels less than 30kg so, for smaller kilns weighing less than 30Kg, the kit is generally one shelf and four posts: included in the price because it fits in the box and doesn't add much to the shipping weight.
You get a professional, durable, cordierite shelf with four 12mm high posts. You don't get a soft, ceramic-fibre shelf, often described as free, that will gradually break up and need replacing.
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.
The recommended kit is usually the simplest that works: not an expensive collection that I've put together for you. However, extra shelf kits allow you to stack your work, optimising your use of the firing chamber volume, the unit-cost of firing, and your time. And extra half-shelves or smaller shelves allow you to fire a mix of shorter and taller pieces.
For larger kilns weighing more than 30Kg, shelf kits are not included in the price because you'll probably want to choose your own mix of shelves, half-shelves, smaller shelves, and assorted-height posts.
One shelf should stay on the floor of the firing chamber all the time in case you accidentally spill or melt anything: solidified glass or metal is impossible to pick off without damaging the ceramic-fibre or firebrick.
Shelves are not meant to be an exact fit in the kiln. You need finger space all round and they mustn't scrape the kiln walls every time they're put in or taken out. Be careful lifting heavy shelves out of a top-opening kiln: if you drop them they will damage the firebricks.
Although they look tough, most ceramics break if they're dropped on a hard floor, so it's a good idea to have spare shelves, especially if your business depends on your kiln or you're running courses.
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 the 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.
You might want a 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.
Shelves are heavy, so kits ordered separately 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.
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. However, if the kin has elements in the bottom as with the Mini-Kiln and Prometheus Pro-7, a cloth or block will act as insulator and the kiln might overheat.
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, ceramic 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 front page. And they're all in the on-line shop.
Shelves are checked before despatch and are wrapped protectively. But they're not guaranteed and we cannot be responsible for any later damage.
|OPTIONS AND UPGRADES: A GENERAL INTRODUCTION|
Individual kilns are described on this this page. However, it's important to learn about options and upgrades as some have to be factory-fitted. The photo shows a Paragon SC2 customised for a PMC silver clay studio: hot pink, a right-hand door hinge, and a maximum temperature set to 925°C so that students couldn't accidentally melt their silver.
An option is cosmetic or practical, such as a black respray, a right-hand door hinge, a peephole-vent, a bead-annealing door, a door or lid viewing window, or an EU plug.
An upgrade extends the standard specifications, such as a higher maximum temperature, a 3-key to a 12-key programmer, an electric kiln vent, a gas injection control system, an auxilliary power output, and a USB computer interface.
Not every option or upgrade applies to every kiln, so mail or call if you need help. 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 as you read?
Kilns use regular single-phase 230V-240V mains so have 230V EU elements, not 120V US elements. The smaller kilns 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 a factory-fitted EU plug.
Most kilns can be re-engineered for 110V, 200V, 208V, or 220V, 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, to use 1290°C full-on hour after hour, choose an industrial or professional model.
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.
The UK factory-set maximum temperature is based on a reliable average voltage of 240V. If there's a regional, national, or temporary voltage drop, high-temperature kilns might take longer to reach their specified maximum or not reach it.
Some kilns are normally blue, but can be factory-painted berry, black, jade, navy, 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.
Changing the door hinge might be better if your kiln is in the corner of your studio or there's an obstacle that will make access difficult. Give this some thought.
Most of the medium-size top-opening kilns have a standard lift-up lid. Firebrick lids seem heavy to some people so, if you feel that a ceramic fibre lid, a hydraulic-assisted lid, 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 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.
Depending on the kiln, you can upgrade a Sentry Xpress 3-key programmer to a Sentry 12-Key ten segment ramp-hold, or cone-fire 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.
A 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 in the on-line shop.
Depending on the kiln, the 12-key programmer has a power-ratio feature: you can adjust the heat balance between the top and sides in 10% steps and control the heat distribution over larger pieces.
Kilns which only heat from the top, as opposed to the top and sides, don't have the power-ratio feature. However, the initial cost-saving has to be offset against fewer firing options.
With larger kilns, serious glass artists are always concerned about firebrick dust from the lid falling onto their work, so you could upgrade the standard firebrick lid to a factory-fitted ceramic-fibre lid with the elements threaded through pinless grooves in the fibre: or, as a luxury upgrade, with the elements completely embedded in the fibre.
Most kilns come with an electro-mechanical long-life nickel-chromium K-type thermocouple. However, if extra long-life and reliability are vital, you can upgrade to a mercury relay which has a lifetime of several million on-off cycles. The relay can switch 30A, so if you have a kiln that needs 50A, you'll need two relays.
If extra long-life and reliability are vital, especially at temperatures above 1100°C, you can upgrade to a long-life S-type platinum-rhodium thermocouple.
Some front-opening kilns are just too large and too heavy for a regular worktop, so Paragon makes a strong steel table, 768mm x 768mm x 718mm high, with two shelves for your accessories. The luxury version, with castors, is 63mm taller. If you decide to buy on old wood table, the rigidity of the legs is vital otherwise it will collapse like a parallelogram.
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 and E10A can hold a one-litre container: most other kilns can hold a three-litre but check the internal size before you buy the container. It's important that the container doesn't touch the thermocouple.
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 UK-EU 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.
For help, or in the unlikely event of a fault, you can mail or call an engineer in the UK. However, home checks, adjustments, and repairs are quick and easy, needing little more than a PosiDriv screwdriver, and you can watch on-line videos. Alternatively, we can repair the kiln in our workshop at Cherry Heaven.
As with a lot of heavy consumer products made in the US but sold elsewhere, Paragon's guarantee covers replacement parts, not a return to the distributor or factory, and not any labour costs. However, as an example, replacing a programmer takes just a few minutes.
|AN ELECTRIC KILN VENT|
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 airborn pollutants straight away and redirects them to the outside through a flexi-pipe. The kilns can be factory-readied, so the vent just need on-site assembly.
The vent motor isn't so powerful that the heat-up time and maximum temperature are reduced, but the cooling time is, depending on the size of the kiln.
The UK-EU vent motor is rated at 230V-240V 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 or block them with some ceramic cloth?
The vent can be turned on and off manually. Alternatively, if the kiln has a Sentry 12-key programmer or a Sentinel Touch Screen, the vent 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.
|A GAS INLET FLOW METER|
During heat treatng, oxygen forms a scale on the surface of knife blades, metals, and tools. To minimise this, the parts can either be wrapped in heat-treating foil or an inert gas can be injected into the furnace to displace the oxygen.
Most professional knife makers use gas injection for precise control and to save time. If you have a Sentry or a Sentinel Touch Screen programmer, a solenoid kit can automatically turn the gas on or off for each segment of the firing: just programme the controller to turn on the gas at the temperature where scale begins to form on the steel.
In addition to the flow meter, you'll also need a regulator to reduce the pressure from the gas tank. This is usually bought with the gas tank: it's not part of this Paragon option. The gas pressure to the flow meter should be less than 20 pounds per square inch.
Furnaces aren't air tight and gas will leak out through the firebricks and metal seams, so you need a steady flow of gas. Gas at room temperature will expand to over twenty times its volume when injected into a firing chamber at 550°C, so a low setting on the flow meter is adequate to prevent most scaling.
Depending on how you work, gas injection might reduce the life of the heating elements slightly. However, they're easy and inexpensive to replace. If your business depends on continual kiln time, buying a spare set of elements would be sensible.
Argon gas is popular for heat treating because it's inexpensive. But, it's heavier than air and breathing it in won't keep you alive. so your workshop must be well ventilated.
Generally, as soon as a programmable kiln starts its firing sequence, it begins to heat up at a rate set by the programmer. It can't heat up quicker than it would do with the elements full on.
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 sequence segments: the heating rate, the target temperature, the hold time, and the cooling rate. It can't cool down quicker than it would do with the kiln turned off. When the sequence is complete, the kiln beeps, and the sequence 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, and in small kilns rather than large kilns. 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 starts to fall. 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 oscillate either side of the target temperature.
This is similar to central heating. If you set it for 21°C, it probably oscillates, quite slowly, around 20°C to 22°C: and you won't notice. The accuracy will depend on where the thermostat is sited, how quickly it responds, how accurate it is, how long it takes for the radiators to heat up, and if you have doors and windows open. The temperature will probably be slightly different in each room.
So, 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, and even produce whisps of smoke, during the first 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.
|KEEPING A KILN LOG|
Using your kiln successfully needs critical research and frequent tests, especially as things that work for your friends and 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. Add a few photos and sketches, and mark the page corners with coloured dots or symbols as a quick reminder of your success rating.
A kiln log is vital if you're experimenting with temperature-sensitive materials or working with coloured dichroic glasses, enamels, glazes, or china 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.
Some Paragon kilns have a Sentry 12-key or a Sentinel Touch Screen programmer which 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 in the on-line shop.
|A BRIEF INTRODUCTION TO CLAYS|
Clays are formed naturally over millions of years as rocks break up into minute particles. They consist of hydrous aluminium silicates and other compounds such as feldspar, iron oxides, mica, and quartz. Clays are collectively referred to as ceramics.
Clays are often divided into three main categories: earthenware, porcelain, and stoneware. Generally, they needs to be fired for several hours, although the exact chemical composition affects the firing temperatures and times, and the clays' colour, porosity, shrinkage, and strength.
|EARTHENWARE, PORCELAIN, AND STONEWARE|
Earthenware is normally beige, red, or white. It has the lowest firing temperature of the three, usually about 1150°C. It's slightly porous, and stains and chips easily, so it's often glazed to protect the surface. Its porosity means it's good for making planters and oven steamers, but not good for pitchers or vases.
Porcelain is composed of kaolin, or china clay. Kaolin doesn't melt until 1800°C, so other compounds are usually added so it can be fired between 1250°C and 1400°C. For example, bone china is made by adding bone ash to the clay. It's known for its whiteness, hardness, smoothness, durability, and translucency. When tapped, it makes a distinctive ping: or ming.
Stoneware is normally beige, grey, or red-brown. It's usually fired between 1150°C and 1300°C. It's hard, durable, and resists thermal shock. Glazes bond well, so it can be made waterproof.
Bisque is clay which has been fired once, without a glaze, to a temperature just before vitrification. Firing changes the clay into ceramic material, without fully fusing it. A second, slower, firing melts the glaze and fuses it to the clay body.
Polymer clay is a man-made material: tiny particles of polyvinyl chloride mixed with plasticizers and pigments. When it's baked, at around 125°C, the particles fuse and the clay hardens.
Raku was originally a Japanese technique, but it's now become an internationally popular way to make decorative ware, with each piece having a unique blend of colours.
A bisque piece is fired to about 950°C, then glazed. It's removed from the kiln when red-hot, and put straight into a container of combustible material.
The flames, reducing atmosphere, and mix of chemicals stain the clay. When the piece is removed and quenched in cold water, interesting colours and shades remain: often unpredictable.
|A BRIEF INTRODUCTION TO GLASS|
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 brittle glass called quartz glass.
To lower the melting point, and reduce the cost of melting, chemicals are added: typically sodium carbonate and calcium oxide. Other chemicals, and different heating and cooling processes, produce a range of colours and mechanical properties.
Chemically, glass is defined as an amorphous solid but, as it's heated, it becomes softer allowing it to be blown, cast, coated, decorated, engraved, heat-treated. moulded, poured, pressed, sagged, and slumped.
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-to-brown glassy type of stone, shown in the photo. Although it was used decoratively, when it fractures it has very sharp edges, many times sharper than a steel knife-edge, so was also used for tools and weapons, and the pitiful ritual of circumcision.
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. It's quite a long process, so a kiln with an automatic comprehensive programmer is essential.
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 vapourised onto the surface of the glass using a vacuum deposition process, forming a multi-layer crystal structure.
To fire polish glass, return the items to the kiln and melt them just enough to give a smooth polished appearance. It needs a temperature of around 700°C, and is typically used to round the edges of glass between fusing and slumping.
Fire polishing already-slumped items is more difficult because the polishing temperature is close to the slumping temperature and it can distort the appearance of the piece. So it generally works best for flat items, rather than slumped ones. It has the slight limitation that the part of the item that touches the kiln shelf won't polish.
|FUSING, SAGGING, AND SLUMPING|
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.
This a simple technique but it requires good ideas. A bottle, such as those used for wine, beer, cola, or champagne, is softened in a kiln so that it begins to flatten out or conforms to a mould. There are too many moulds to stock here but there are lots available on line. Or make your own from clay.
The bottles nead to be clean and dry, with all paper labels and tops removed. Put them in your kiln on a shelf, either with shelf paper or kiln wash to prevent the glass sticking to the shelf. Paragon make a kiln designed for this: the Trio. It's wide enough for most bottles but can still use a regular socket.
|LAMPWORK AND BEADS|
Very briefly, lamp-working is the traditional name for glasswork that uses a flame to melt glass rods and tubes. As the glass softens, it's shaped by turning and using tools.
Early lampworkers used an oil-lamp, and blew air into the flame through a pipe. Later, propane, natural gas, or butane torches replaced the lamp, although kilns are now increasingly popular, particularly for annealing.
Beads are usually made on steel rods, or mandrels. When the beads are finished, the rods are removed leaving holes for threading the beads. Cold working techniques can be used, such as etching, faceting, polishing, and sandblasting.
|PÂTE DE VERRE|
Pâte de verre involves making a glass paste, applying it to a mould, firing it, and removing the piece from the mould. The glass paste is usually made from glass powder, a binder such as gum arabic, distilled water, and colouring agents or enamels. It allows precise placing of colours in the mould, whereas other techniques often result in the glass straying from its intended position.
I think, currently, Daum is the only large commercial crystal manufacturer using the pâte de verre process for art glass and crystal sculptures.
Tack fusing is the joining together of glass, with as little change to the shape of the pieces as possible. Tack fusing may be used either decoratively, or to assemble a large piece of glass from laminations.
Where tack fusing is used to apply small decorative details to a larger piece, you might want to partially melt the small pieces so that they change shape, usually becoming more spherical under the influence of surface tension, but without changing the shape of the carrier piece. This can be done by using an increased temperature, but only briefly. The carrier piece has a larger thermal mass, so heats up more slowly than the small decorations.
Vitrigraph uses a Caldera-A kiln to make glass stringers. The bottom of the kiln is unclipped and set aside. The kiln body is put on a thick ceramic square with a central hole. The whole thing is lifted well away from the floor to allow moulten glass to fall through a small hole in a crucible and form long stringers. Ceramic squares are in the on-line shop.
The term warm glass refers to fusing, slumping, and other glass processes which take place at temperatures between about 600°C to 925°C. Although that doesn't sound warm, it is when you compare it to glassblower's working temperatures, which often exceed 1100°C. The term warm glass is often replaced by kiln forming.
is a Cherry Heaven internet resource. Cherry Heaven is a UK-EU distributor for kilns, and has been one of Paragon's top-selling distributors consistently from 2006 to : a pleasing outcome since the UK is only one third the area of Texas and one fortieth the area of the US.
As this is an on-line resource, 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, diagnostics, repairs, or reselling opportunities.