30 October 2015

TEST AND TRIALS: SPONGING

I have a range of shapes and patterns but my ceramics are always developing and I'm trialling a new design and a new method - sponging. The method of sponging designs under the glaze to white pottery is long established - Emma Bridgewater does it well - but I'm not aware of anyone who's done it on glaze, maiolica style. Sponging has a nice texture you can't get any other way, it repeats regular shapes, but with pleasing variation, it's quick and - I admit it - I like playing around with new ideas.

This (left) is the kit. Dense sponge, a knife, a blowlamp to heat the knife, which cuts when hot, tile to mix the colour, palette knife to grind it smooth, brush to mix. The foam makes noxious fumes when burnt so I will be wearing a mask next time.

The first results are pleasing, and it has potential, though there's a long way to go. Watch this space.

22 October 2015

OPENING THE KILN

However long you do ceramics, a kiln firing remains nerve-wracking and you always open the kiln with trepidation. Today I finished a firing and took out 70 pieces, nearly all of them good.

Firing an electric kiln isn't as easy as is often made out. Sure, you can get the controller to switch the kiln off while you're asleep in bed, but kiln thermometers are inaccurate, all kilns have hot and cool spots, and anyway you have to measure heat-work, not temperature, and that requires pyrometric cones. In my 14 cu.ft. (400 litre) kiln I use two sets of cones because the top and bottom can differ by almost a cone (roughly 20 deg. C).  The last two hours of firing call for as much fiddling with sector switches, vents and bungs as a gas kiln.

Through repetition and experiment I've eliminated the grossest faults in my firings. Crazing and crawling are the opposites of each other, but I've had them both. Glaze chipping off the edges of pots is a hazard of tin glaze, and I've pretty well got rid of that. Colours running - got rid of that too. There's always room for improvement, of course - a slight adjustment of glaze thickness, some modification of the colour, better control of the brush, and in this firing I tried some new designs which will go into production when they've been refined. But on the whole, satisfactory.

12 October 2015

ST. JOHN NEPOMUK TOMB, PRAGUE

"Baroque excess" is a tautology, but the glorious silver tomb of St. John Nepomuk by Fischer von Erlach in the Cathedral of St Vitus in Prague cannot be described without tautology. I took a few pictures with a poor camera in the low light of the church, but they give some idea of it.