Making the SC-2 silver clay kiln in the Paragon factory.
Don’t be disheartened if a fired silver clay piece is brittle. You can strengthen it by firing again using a temperature and hold time shown below. You can also repair and re-fire broken pieces.
Silver clay is composed of silver particles held in a binder. For maximum strength, the silver must be fired hot enough and long enough to completely burn off the binder. Only then will all the silver particles fuse together.
For maximum strength, fire silver clay to these temperatures:
PMC (all versions): 1650 degrees F, hold for one hour
Art Clay Silver (all versions): 1600 degrees F, hold for one hour
If you include glass or other materials that cannot fire to 1600 – 1650 degrees F, then use a silver clay version that is designed to fire to a lower temperature. Or for maximum strength, fire the silver clay twice. The first time, fire the silver alone to a temperature above. The second time, fire the silver combined with the other material (such as glass) to a lower temperature.
REPAIRING BROKEN PIECES AFTER THEY HAVE BEEN FIRED
A fired silver clay piece may have broken due to hidden cracks rather than to a low firing temperature. Handle unfired pieces with care. They crack easily, and the cracks are often difficult to see.
To repair a broken piece, first clean it. Then repair with silver clay paste and fire again to one of the above temperatures.
Q. What causes purple spots in gold glaze?
A. Purple spots in gold can be caused by overfiring or by too heavy an application. However, this is very attractive when gold is crackled over a dark color of fired glaze.
Q. If I turn the Limit Time dial to 5, the Kiln Sitter always shuts off at around 4. What Limit Timer settings should I use for greenware, underglaze, and glaze?
A. If the Kiln Sitter shuts off at around 4, then turning the dial to 5 gives you a one-hour margin of safety. This means that after the cone bends and shuts the kiln off, there is still one hour of time left on the Limit Timer. If the cone failed to bend and the Kiln Sitter did not shut off, the kiln would continue to fire for another hour until the Limit Timer shut it off. I suggest setting the Limit Timer half way between 4 and 5 so that you have only a 30-minute safety margin.
Set the timer for 30 minutes past the shutoff time for each type of firing. If all firings shut off at four hours, then set the knob half way between 4 and 5 for all your firings.
Q. I work with several other glass fusers in a studio. We were thinking about putting all the kilns together in one room to save on space. Would having the heat from several operating kilns affect the digital controllers on the kilns? What should maximum kiln room temperature be for the kilns to operate properly?
A. A firing room that contains several kilns should be large enough to avoid a buildup of heat. Small storage rooms would not be suitable. The kilns should be spaced about 3' apart to avoid overheating their electrical components. Maximum room temperature is about 110 degrees F when measured 3' from the kilns. Most brands of controllers will flash an error message and the firing will shut down when the switch box temperature is too high. (Paragon's controllers flash ETH--Electronics Too Hot.) To lower the switch box temperature, blow air through the switch box louvers with a small fan.
Last week’s Kiln Pointer included information on adhesives for glass. Paul Traskin of Clovis, California wrote, “I have been teaching a high school stained glass class for several years and have found that DAP brand Aquarium Sealant is an excellent adhesive for glass. It is 100% silicone, which allows it to expand and contract with temperature changes. I have found this expansion and contraction of glass to be the primary reason for the failure of many of the adhesives I have tried. DAP Aquarium Sealant is sold in hardware stores and costs about four dollars for a 2.8 ounce tube. I suspect it would work equally well on glazed ceramics.”
Last week I asked whether you prefer Kiln Pointers in plain text or with graphics. Thanks to those who sent their opinions--your responses filled my email in-box. The answers were evenly divided between those wanting plain text and those wanting graphics.
We are trying to design the format so that the Kiln Pointer will appear in your email system as plain text if you have turned off html or with graphics if you leave html turned on. I don’t know if this will work with all email systems, but we are working on it.
David Gustafson of The Plains, Ohio wrote, “Your information is valuable enough that you can decorate your email any way you wish. You can cut and paste the text into a new text-based document.”
Dan Wade of Dallas, Texas wrote, "I do understand that downloading pictures takes time if you don't have a high-speed connection, but I like the graphics format (I have a high speed connection). The readers who don't what to download the pictures can turn them off. Just go to the Help menu and change the security setting. I use Outlook 2003, which even lets you do it by sender.
“I've not used some of the freebee email services, so I don't know if it can be done there. But have your readers go to the Help menu of their email service and do a search for ‘pictures,’ and it will probably give them options for turning off HTML content.
“In Outlook 2000, turning off pictures is under the Options / Mail Format / Internet format. Just click the block for downloading HTML formatted documents.”
SPECIAL ON FUSION-7 KILN
We are offering the Paragon Fusion-7 kiln at the special price of $735.00 from October 9 thru December 22, 2006. ----------
Recently here at Paragon I was startled to see a mannequin. It was sitting at the front desk wearing a monster mask, its gloved hand resting on a phone. It is the first thing you see when you walk through the front door. When I was small living in Calgary, Alberta, Halloween was a favorite time of year. It was one of the few nights that I was allowed to stay out past 8:00 P.M.
With best wishes,
Arnold Howard Paragon Industries, L.P. - Better Designed Kilns 2011 South Town East Blvd. Mesquite, TX 75149-1122 Voice: 972-288-7557 & 800-876-4328 / Fax: 972-222-0646 firstname.lastname@example.org / www.paragonweb.com