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Explanation of Options for Round Kilns
 

Furniture:     Most customers will purchase the furniture kit, as without the kit the user would be limited to firing ware just on the kiln bottom.  The furniture kit for each kiln consists of kiln shelves, posts and kiln wash, with the number of shelves and posts varying according to the size of the kiln.  The kiln shelves allow ware to be stacked in the kiln, and to fully utilize the interior of the kiln, will be as large as possible but still allow the fingers of the person loading the kiln to avoid contacting the wall bricks.  The kiln shelves will be either full shapes, or half shapes, or a combination of both.  The 22" deep kilns will typically accommodate 3 layers (a combination of 3 full or 6 halves) of shelves.  The 29" deep kilns will accommodate 4 layers of half shelves (8 total).  Please note that in large volume kilns, the shelves will typically be half shelves for ease of loading and better heat distribution and cooling within the kiln.  The kiln posts provided in the furniture kit will be sufficient for the number of kiln shelves, and will typically be a mix of sizes from 1" up to 6" in length with 8" posts added to the kit for some large kilns.  Additional length posts, up to 12" in length, are available.  Kiln wash is used to coat the shelves and prevent drips of glaze from binding to the shelf.        Kiln shelves are often heavy and can be very difficult (or even impossible) to pack for UPS shipments.  Local customers may purchase additional furniture at any time from Dogwood Ceramic Supply's inventory of kiln furniture, but customers that need furniture to be shipped to their location are advised to purchase the desired furniture at the same time as you purchase the kiln.

Stands:     The standard kiln stand, shown to the left, comes with each top loading round Paragon kiln was designed to support the weight of the kiln and accommodate the Orton KilnVent.  Paragon makes an optional Deluxe Kiln Stand that is equipped with 2" steel casters, shown to the right.  If you have the need to frequently move your kiln, the Deluxe Kiln Stand is perfect for you needs.  Please be advised that the deluxe kiln stand can not be easily used with the Orton Downdraft vent system.

Orton Vent Master:     The Orton downdraft Vent Master is designed to remove noxious gases from a kiln during firing and exhausts the gases from the room.  For more information regarding kiln ventilation please refer to Dogwood Ceramic Supply's Orton Vent Master section on the Paragon Information page.     The optional Auxiliary Output (AOP) mounted on the control box of the kiln.  The AOP is a factory installed power supply that is operated through the Orton Sentry 2.0 digital Controller.  By programming the Sentry 2.0 controller and powering the vent through the AOP, the Vent Master can be operated in the most energy efficient and optimum mode for each type of firing.     Please note, the Orton Vent Master can be easily retrofitted to a kiln after purchase, but the AOP is only available as a factory installed option.         The Orton Vent Master and AOP is available as an option on most Paragon kilns.

Lid Safety Switch (also known as Door Safety Switch):     Fluid filled rocker switch mounted to the hinge assembly of the kiln that instantly shuts off power to all elements in the kiln whenever the kiln lid or door is opened while leaving the digital controller fully powered and able to resume the proper firing after the lid has been closed.  The lid safety switch is optional on all Paragon kilns but is most commonly used with kilns which have elements in the lid or door, as well as kilns that may require frequent opening and closing of the kiln lid or door during firing.  The lid safety switch is required on all models of kilns exported to the UK.  $70.00 upgrade for all kilns.

S Type:
    S Type Thermocouples are popular with potter's and production studios due to their long life and high degree of accuracy. For more information regarding the choice of thermocouples, please refer to Dogwood Ceramic Supply's S-Type versus K-Type section on the Paragon Information page.  The S Type Thermocouple is available as an option on nearly every kiln made by Paragon.  S-Type Thermocouples are extremely fragile and are easily broken if stuck by a kiln shelf or wares.  The warranty of the S-Type is TWO years except for physically damaged units.

3 Zone Control:
    The standard configuration of the kiln uses a single thermocouple located near the middle of the kiln wall behind the control box.  The Sentry 2.0 Digital Controller computes the temperature of the kiln every second, and then adjusts the firing speed and temperature based upon those temperature readings.  For most customers, the single zone (or single thermocouple sensor) monitoring system works extremely well.  But, as kiln sizes increases, the single zone control is not always adequate.  There are instances when a kiln user, especially somebody doing large sculptural works, may have a terribly unbalanced load in the kiln.  This is especially true when the sculpture has a large heavy base and light weight top section.  In those instances, it may be desirable to monitor and adjust the temperature in multiple locations within the kiln.
    The 3 Zone Control may be added to any large kiln such as the Viking 28 or the TnF 27-3 Short and Wide Kiln.
    3 Zone Controls work by monitoring the temperature at 3 locations on the kiln wall behind the control box.  The Sentry 2.0 Digital Controller computes the temperature from each of the 3 regions (zones), compares the temperatures, and if one region of the kiln is firing hotter (due to a lighter load of clay or kiln shelves in that region), the digital controller cuts the power to that region to allow the cooler or more heavily loaded regions to catch up.  Thus, an unbalanced kiln load is adjusted to quickly and evenly fired to same temperature throughout the kiln.
    Should a customer add the 3 Zone Control to their top loading Paragon kiln is best determined by the anticipated needs of the kiln by customer.  If it is known that the kiln will be regularly fired with well balanced loads, there is absolutely no need for 3 Zone Control to be added.  If the kiln will be used for a wide variety of sizes and shapes of wares, careful distribution of the kiln shelves and ware should prevent the need for the 3 Zone Controller.  If, on the other hand, it is known that a kiln will nearly always be very unevenly loaded, 3 Zone Control most likely should be added.
    As with the Single Zone Control, the 3 Zone is available with either K-Type or S-Type Thermocouples.  If a 3 Zone Control is optioned, all 3 thermocouples must be of the same type.  Please note, 3 Zone Control can be operated as a Single Zone Control (in the event of a thermocouple failure, or if so desired), by changing a simple user accessible code on the key pad of the Sentry 2.0 Digital Controller.
    Due to wiring concerns, 3 Zone Control must be installed at the time the kiln is manufactured.

APM Elements:
    Standard kiln elements from all kiln manufacturers are made from Kanthal A1 or equivalent wire that is designed for a maximum temperature performance of Cone 10.  For must customers, the conventional element performs extremely well and are quite durable.  However, at temperatures above Cone 6, especially in the presence of some corrosive gases, the Kanthal A1 wire may suffer premature fatigue and failure.   Theses gases are generally found with home made glazes that are "pushing the envelope" or in industrial settings.
    APM elements are an advanced alloy produced by Kanthal that is resistant to many of the corrosive gases that could be produced from pottery glazes, are rated to perform to approximately 2700°F (much hotter than Cone 10 at 2340°F), and do not incur resistance changes over time from usage.  Bottom line, APM elements are far superior to the conventional elements.  They are also relatively expensive.  For comparison purposes, on the Paragon Dragon, the APM elements are $925 (MSRP) upgrade.
    Customers that routinely fire to Cone 10, or near Cone 10, and have experienced the need to frequently (monthly, weekly, every firing) change elements in their existing kiln due to the glazes that they are using may want to consider adding APM Elements to their kiln.  The good news is that APM elements can be retrofitted to any kiln at any time.

For Janus Series of Kilns

Mercury Relays:
    Yes, the Relays really can be filled with Mercury.

    Most Paragon Kilns use a mechanical relay that controls the flow of electricity to the elements.  On and Off, On and Off, the mechanical relays are constantly cycling.  In the typical pottery kiln that on-off cycling is usually a few seconds on followed by several seconds off as the temperature is slowly built up in the kiln.  This slow cycling allows the relay to cool off between periods of being on and prevents premature relay failure.  The basic glass fusing kiln will follow a similar pattern of on-off and the mechanical relays work quite well for such kilns.  But for glass artists that will be holding the temperature for long periods of time the relays become over worked with frequent on-off cycles.  Often the on-off cycling is so frequent and of such a short duration that the noise generated from the relay is best described as chattering.  In a manner of speaking the relay is doing it's job at a normal pace of performance.  But in a kiln environment, with all the heat of the kiln chamber very close by, it is difficult for a chattering relay to dissipate the heat generated from the frequent on-off cycling.  Heat is not very friendly to a mechanical relay and premature relay failure is common.  Enter our friend the Mercury Relay.  Mercury Relays are ultra heavy duty, capable of handling large amounts of electrical current.  Mercury also is wonderful to dissipate the heat of frequent on-off relay cycles.
    Why not make Mercury Relays standard equipment?  The issue is not the Mercury, as the relays are sealed and failure is very infrequent, but because the Mercury Relays are expensive.  Depending upon kiln amperage the Mercury Relays can cost as much as $195 per relay and some larger kilns can require 2 to 5 Mercury Relays depending upon the electrical specifications of the kiln.
    Should you add Mercury Relays to your Janus kiln for glass use?  The best answer to that question is how hard will your kiln work, especially holding temperatures for extended periods of time, plus the location of the kiln.  Is your kiln going to heavily used with hold times of 2 hours at one temperature while located in an outdoor work shed near Death Valley?  Then add the Mercury Relays as the work load on the kiln as well as the high ambient temperature will most likely cause premature relay failure.  Is the kiln going to be located in an air conditioned room with the kiln temperature seldom held for more than a few minutes?  Then skip the Mercury Relays as the regular relays are $28 to $48 and it will be difficult to recover the added cost of the Mercury Relays.  Kilns between these two extremes are difficult to judge.  Replacing standard relays are not very difficult for those who are handy with basic tools.  But there are those issues of premature relay failure that always seem to occur during a critical firing.  Historically about 50% of all GLASS customers will opt for the Mercury Relays.  For Janus kilns that are going to be used primarily by potters the upgrading to Mercury Relays is often overkill.
    Please note, Mercury Relays are standard equipment on the Paragon Viking, Dragon and Super Dragon due to the electrical draw of the element groups in the kiln exceeding the amperage rating of the mechanical relays.

Mercury Relay shown to the left, conventional mechanical relay shown to the right.  There is a significant mounting difference between the two types of relays and user upgrading is not easily accomplished.