Author archive for Derek

  • Heirlooms

    區建公 Au Kin Kung

    區建公(1887年-1971年12月31日),名建邦,字维屏,號建公,又號聽香樓主,廣東新會人,一生致力文教工作,精書法,兼善各體,尤以北魏書體獨步書壇。

    區建公少年即從宿儒盧湘父,修習經史詞章之學。1906年畢業於新會師範學堂,1912年於澳門創立德華學校,1927年於香港設建邦學校。課餘精研書法,篆隸真草皆擅長,譽滿書壇。1930年在香港設立建公書法學院,專心宏揚書藝,扶掖後進,對清貧學生,免費施教,前後四十一年,從未間斷。當時,香港的商號和機構之牌匾和碑記,多出於其手。他又編印書法示範十餘種,習字帖百餘款,為當年中小學廣泛採用,有助於香港書法藝術的普及和提升。

    區建公亦精於醫學,受業於外祖父劉宗仁,並奉母命贈醫濟世。他在1971年12月31日去世,享年八十五。

  • Heirlooms

    周世聪 Madame Chow Sai-chung

    历任香港万国艺术专科学校监督兼校长,中国艺术协会主席,亚洲妇女协进会永远当然会长,中国文化协会委员,香港书法家协会顾问,日本国际书道协会委员,美国国际华人艺术协会顾问等。

  • Jingdezhen

    Chinese Cones

    I can't but help think my cones are giving me the finger..

  • Jingdezhen

    Gaolin Mountain

    The traditional source of Kaolin clay used in Chinese porcelain is Gaolin mountain.  There’s actually not much to see at the park there- all the kaolin clay was mined out a very long time ago.  But the mountain itself is beautiful, and the nearby villages still offer a glimpse into “old China”.

    The village at Kaolin mountain.

    Although there’s not much to see related to ceramic history, the mountain is beautiful.

    One of the old mine shafts at Kaolin mountain.

    A waterwheel fed by one of the mountain streams.

    The old village is quaint and peaceful.

    Traditional houses are found in the smaller villages around Kaolin mountain.

  • Porcelain Body

    Natural Quarts and Mica additions to porcelain

    Test of adding natural quartz and mica to porcelain.

    Porcelain is Taida 609 fired to 1310 celsius in reduction.

    Top row: 5, 10, 15, 20% addition of silica to 100g porcelain slip
    Bottom row: 5, 10, 15, 20% addition of mica to 100g porcelain slip

    IMG_6430

    The natural quartz has a ton of impurities. Also I did not consistently grind or filter the quartz. Addition of quartz impedes translucency.

    IMG_6436

    I’m not sure exactly what type of mica I used. However, it seems pretty clean and of uniform particle size. Didn’t notice translucency affected much. The last tile is a little thicker than the others so appears more opaque.

    IMG_6438

  • Uncategorized

    CGGHZ Chinese Glazes Guan Hangzhou p82

    Chinese Glazes Hangzhou Guan Glazes

    Table 29 p269

    CGGHZ 1
    PF 27
    CC 21
    QU 29
    Wh 18.5
    DO 3
    RIO .5
    BA 1.0

    CGGHZ 2
    PF 30.5
    CC 18.5
    QU 27
    WH 19
    DO 3
    RIO .5
    BA 0.7

    CGGHZ 3
    PF 24
    CC 25.5
    QU 28.5
    WH 18
    DO 3
    RIO .6

    CGGHZ 4
    PF 31
    CC 22
    QU 25
    WH 16.5
    DO 4.0
    RIO .5
    MD 0.2

    2013/05/13 1270C reduction, sub .3 YIO for RIO

    cgghz4

    cgghz3

    cgghz2

    cgghz1

    cgghz

  • Photos

    Stockholm

  • Techniques

    Omega HH506RA Pyrometer

    In the future I’ll be adding articles to this website.  The first article that came to mind was a review of an excellent pyrometer I recently purchased, the Omega HH506RA.

    Omega HH506RA Dual Input, High Accuracy Datalogger/Thermometer ($199USD)

    I was looking for a thermometer to use primarily with my gas kiln, preferably a portable version that i could easily detach and use with other kilns in my workshop.

    My main requirements were:

    • At least two inputs for the two thermocouples (top & bottom) in my gas kiln.
    • Multiple thermocouple types.  I fire the gas kiln to cone 9-12 so prefer S-type thermocouples for their greater accuracy (0 to 1600°C continuous temperature range) and longevity.  But for my cheap bisque electric kiln I use K-type thermocouples (0 to +1100°C).
    • Real-time datalogging using a serial or USB cable which can be connected to a computer.  Ideally, the data should be transmitted in a non-propriety format which can be read directly from the port or from a simple text file.  (Logging is important as I’m also helping a ceramicist friend who wants to view firing data from his kilns while he’s out of town.)
    • Dual voltage, or preferably battery operated.
    • Rugged housing, solid build quality.

    Fluke offers the Series II Model 52 which has two inputs and datalogging.  However, from reading the manual it seems that the data can only be viewed on the computer through Fluke’s proprietary FlukeView Forms software, adding at least another hundred dollars (for the basic version) to the over $300USD cost of the thermometer.

    After looking through the Clayart mailing list archives I started looking into Omega thermometers.  Omega’s website (www.omega.com) can be quite confusing due to the abundance of options available, but after much searching it seemed that the Omega HH506RA would meet all my requirements.  A quick response from Omega support confirmed everything I needed to get things working.

    • Omega HH506RA Thermometer ($199) 2-Channel Temperature Measuring, 7 Thermocouple Types , Triple Display with Setable Backlight , Triple Display with Setable Backlight , Save Data (128 Samples with Real-Time Data), Datalogging (16 Sets, Max 1024 Data Capacity), Time, Record Interval, APO Time Setting , Software Package Included (RS232C Cable and Disk, Model HH506RA Only), °C/°F Switchable , 0.1 Resolution , Water/Splash Resistant, NEMA-4X,, Dustproof
    • Accessory HH506RA-USB-SW ($30) USB cable and software for Win98/NT/2000. The HH506RA already comes with software and a RS232 cable.  But a lot of computers don’t even have RS232 ports anymore, so I added the USB cable.
    • Miniature Thermocouple Connectors Flat Pin  (Part number SMPW-K-M for K-type, SMPW-R/S-MF for S-type.) You will need one male connector for each type of themocouple you’ll be using.  The connectors are easily be attached to the ends of thermocouple wires and then plugged into the thermometer.  I purchased two S-type connectors for the gas kiln and two K-type connectors for the electric bisque kiln.
    • R and S Type Thermocouple Extension Wire  I already had thermocouples and wire.  But if you need to purchase the wire, Omega sells it in a minimum of 25′ rolls.  Part number EXTT-RS-20-25.

    Installation

    As I mentioned, I already had thermocouples and wire.  So all I had to do was attach the thermocouple wires to the Omega connectors and then insert into the thermometer.  I was concerned that simply adding the Omega connectors and thermometer would lead to accuracy problems due to the length and gauge of the wire not being matched to the thermometer.  After many tests against my old pyrometer and cone firings, I was happy to find that the Omega is very accurate.

    As you can see in the above picture, my thermocouple wires are thick-gauge, much thicker than the Omega connectors are designed to be used with.  But they work together just fine, even though the connector covers cannot be used.  Thermocouple inputs and USB/RS232 input are all located at the top of the unit.  The display is quite clear and has an illuminated display.  Thermometer controls are fairly easy to figure out.  You need to adjust the settings to match your setup.  As you can see in the display, the current reading is 9°CS, C representing Celsius and S representing the type of thermocouple.  Mismatching the thermocouple type with thermometer settings will give incorrect readings.

    Output from the HH506RA using the Omega software

    The USB cable is easily connected to a computer.  The Windows software is quite old but simple to install and run.  The dual temperature displays and temperature difference display are very nice, but unfortunately I’ve found the graphing function unusable.  Fortunately, the simple tab-delimited text file output of the Omega software is easily imported into spreadsheet applications like Excel and Google Docs.

    Using Excel with Omega temperature output

    The Omega temperature output file as viewed in Excel and simple text (above).

    Using Google Docs

    Below, the file after being uploaded to Google Docs and viewed in a simple Line Chart.  The same could be done in Excel.
    By the way, the above graph shows my firing schedule.  This instance isn’t a particularly good firing.  Slow rise first hour to get rid of moisture, fairly fast to 800, from 800-900°C soak with slight pressure for a couple hours until kiln evens out, begin reduction just after with gradual decrease as reaching temperature, soak for another hour until Chinese cone 9 drops (about 1310°C), crash cool with full open damper until 900°C.  It’s a ten (in this case, twelve) hour firing but doesn’t take a lot of gas due to the three or more hours of relaxed soaking.

    Conclusion

    At $199USD the Omega HH506RA thermometer is an excellent value.  I’ve already used it for a year and haven’t had any problems.  It’s built solidly and the original 9v battery hasn’t died yet.  I really like the display on the computer monitor, especially the difference between the two thermocouple readings.  It would be nice if Omega had better software for looking at graphs, but since the files are easily imported into Excel this isn’t much of an issue.
  • Craft

    纪录片《china-瓷》

    It’s said that you can tell how long a foreigner has been in China by the number of appearances they have on Chinese television.  I’m not doing well, I guess, because I’ve only been in one documentary.

    “China · porcelain” is a documentary about the fascinating history of Chinese export porcelain in the Ming and Qing dynasties, including Chinese porcelain’s influence on world trade, culture, and the economy.
  • Glazes

    The Glaze Sprayer Maker

    Some of the tinsmith's tools

    Templates for glaze canisters

    Each type of glaze canister has a specific application, from spraying large sculptures to detailed underglaze application.

  • Techniques

    New kiln

    Steel-frame fiber propane gas kiln, six venturi burners, single shelf (64x64cm).

    Steel frame of gas kiln in progress

    Steel frame of gas kiln in progress

    Steel frame of gas kiln

    Steel frame of gas kiln

    Completed gas kiln with steel frame and stainless steel panels

    Completed gas kiln with steel frame and stainless steel panels

    Inside of completed gas kiln

    Inside of completed gas kiln

  • Jingdezhen

    New Studio

    The building had been abandoned for a number of years when we convinced the landlord to let us rent it

    The building had been abandoned for a number of years when we convinced the landlord to let us rent it

    Two months later, renovations complete.

    Two months later, renovations complete.

  • Photos

    Cizhou Kiln

    Some of the old mantou kilns have been converted into shops

  • Photos

    Dinnerplan