Thursday, 24 May 2012

Out Of The Kiln

It’s only when you become a potter yourself do you finally realise how much goes into making a pot. Of course most people know about the throwing and firing aspects, and some people also appreciate that there’s also a lot of designing, planning and preparation that goes on behind the scenes too. But I’m not sure for instance how many people know that even when a pot comes out of the kiln, the story isn’t over yet!

When my pots come out of their final firing (which is when they’ve been glazed) there’s still a couple of extra things I need to do before the pot can go out into the world. My pots are usually made of stoneware clay and fired in an electric kiln. This is quite a ‘clean’ way of firing (there’s no residue left on the pots like there is in raku for instance) but they still need a final check.

First I check that the glazes have all worked properly and there’s no cracks or faults in the body of the pot. Sometimes the glaze will ‘run off’ the pot for instance or a drip of glaze will stick onto the base. If this happens the pot is either a reject or sometimes can be saved by chipping the glaze off with a hammer and chisel. The angle has to be just right, and the tapping has to be ‘just so’, but if you’re lucky the drip of glaze will slice cleanly away without damaging the pot.

Next I check any pots with lids. I always fire my pots with their lids ‘in situ’ which means hopefully a lid will shrink to the same extent as the body of the pot during firing and be a perfect match. However, tight-fitting lids, like those on teapots for instance, do have a tendency to get stuck. The remedy is to hit them with a wooden stick: literally! The best way to release a stuck lid is to ‘tap’ (sometimes quite hard) the edge of the lid where it meets the body of the pot to encourage it to separate. Usually they come free after some patient thwacking, but if they don’t, then I try filling teapots via the spout (or submerging closed forms) with alternating hot and cold water. This usually does the trick.

Finally, I give all the bases of my pots a quick sanding over: and this is what I did today by the way. The bases of pots and any bare/non-glazed areas of exposed clay always feel a bit rough to the touch when straight out of the kiln. This is perfectly normal but when a pot is a functional item – like a jug – it needs to feel comfortable to hold. It’s also important that the base of a pot doesn’t scratch any surfaces when used every day. So I always check the base of my pots and smooth any sharp edges with sandpaper. I use normal medium-strength sandpaper to do this, which is just enough to take away the roughness without losing that rustic charm that stoneware has. Then I wipe the pots with a cloth to clean away any dust.

And that’s it! At least that’s the end of the ‘making’ part. The next stage is another blog post entirely…

Wednesday, 2 May 2012

Storage Jars - How To Make Flat Lids

At the moment life is getting in the way of making pots. This happens quite frequently of course: there’s always something popping up in life to interrupt potting plans. Recently it’s building work that’s causing disruption. We discovered the outside wall directly above my studio space was in danger of falling over in the next bad storm. And bearing in mind there’s been some pretty stormy, rainy and windy weather recently, we decided we’d better get it fixed pronto! All very boring, disruptive, noisy, dusty and stressful etc. And since it’s happening directly over my head, I’m having trouble concentrating on making pots.

However, in between the drilling and hammering and general crash of masonry falling around me, I’ve managed to do some reclaiming of clay at least and even made a few pots. As you can see in the photos, I’ve made some storage jars in the same style as my mustard pots. They have a simple cylinder design with a small ‘shelf’ area for the lid to sit on and little cut-out holes for a spoon.

The lids are thrown on the wheel from a small lump of clay. They’re made ‘right-way-up’ with the knobs included, which is a bit like making the opposite of a bowl. Instead of making a hole in the centre of the clay, you press down on the edge of the lump to create a flat lid around a central blob, which is shaped to become the knob. I’ve made this little diagram below to illustrate.

As long as you get the amount of clay right for your pot and you measure accurately when throwing, this is a very efficient design. No clay is wasted and it requires only a small amount of ‘clean-up’ when leatherhard: just a wipe over the base with a damp sponge. The holes have to be cut at the optimum time: the clay can’t be too soft or too hard or they won’t be nice and crisp. I used to use a round looped tool to make them but this time I discovered my small cookie cutter is the perfect size.

I’ve always liked storage jars, especially with lids and holes like these! And there’s something very satisfying about getting a lid to fit snugly onto a pot. Anyway, these pots are drying now and waiting to be bisque fired. In the meantime I’m hoping the building work will be over soon so I can get back to normal potting.