The maiden firing approaches....

Well....here it is! My lovely little new kiln. Finished and ready to go.

Today I biscuit fired all the work that will go through its first firing. A bit of a stressful bisque really - and very slow. There's a real range of clays in there, from smectitic Fen clays (like the Buttery clay), high silica Leicestershire glacial clays and Malvern Carboniferous era ball clays. Some of these are carbonaceous too, but the most problematic is the green clay. It's very fine, beautifully plastic, but not sticky, but very prone to bloating in the bisque as the sulphur that is bonded to its iron content burns out. It is already dense at 1000C so I did a long soak at 700 - 800C in strong oxidation. Fingers crossed.
Packing Thursday, firing Friday.

Arch and sticky sticky clays

The cloudless skies have re-energised me and I've got loads done this week. the kiln is really taking shape - chimney finished (8ft from chimney floor, which seems short but it's a small kiln) and the arch is in place.

Still quite a bit of cutting to do to fill in the side wall of the chamber, then cover with secondary insulation + finish the firebox roof. Next week I'll measure up for all the metalwork.








Alongside this I've been working with many of the non-stoneware clays that I have collected, including local Fen clays, for an 1150C firing in the new kiln. I have managed to use some successfully, with homemade grog additions, but there's been a lot of cracking going on, with a very late sudden shrinkage that indicates highly plastic smectite clay minerals. My reading confirms that this is often the case with these Fenland clays, making them very difficult to work with. I have found one seam of sandy clay that is quite useable as it is (fantastic!) but only have a small sample of it + the area I got it from has now been quarried out.

This will give an idea of some of the new forms I am making - made from a boulder clay collected at Beacon Hill National Park in Leicestershire.

The pit is opened

It took a couple of days to burn through, but today we opened + unpacked the Pit. Not bad for a first attempt with some good pinks and yellows from the seaweed and some colour from copper and soda, as well as the balcks.

I spent the rest of the day on the new wood kiiln. It now has a sturdy shelter (seemingly pointless in this fantastic sunshine) and only 2 more feet to add to the chimney. Arch tomorrow, along with crushing Triassic sandstone to add to my very fine Carboniferous ball clays from the Malvern Hills. More on this and my new work later.....

Sun, sawdust and the Pit

Almost eight months after first planning to do this, instead of rain the sun was shining beautifully and everyone from my morning Throwing Classes turned up with assorted bags of sawdust, straw, bicarbonate of soda and dried seaweed for the now legendary Pit Firing.

It's been dug into the ground, lined with old and now unusable kiln shelves from my dismantled salt kiln and built up with bricks. If we get enough temperature I'm hoping the kiln shelves might fume + add to the flashing?

It was filled up to the top of the kiln shelves, covered with sawdust and woodchip + then a raging bonfire built up on top to get a good bed of hot embers.
Then it was covered with corrugated iron + left to burn through. It's nearly 6pm now + still very hot + smouldering.

The sun is shining and everything is beautiful

Yes, it's glorious to feel the sun on my pallid skin at last and spend some time outdoors, taking a break from blunging, sieving and stiffening various lower temperature clays that I have collected. I've started making from them but am reluctant to post images until the ideas have coalesced and a firing is imminent.
All my bricks are now trolleyed up the field to my kiln site and I've been able to take the corrugated iron off my kiln base and get working on it.

The three sections of the kiln are now visible - firebox, chamber and chimney. The most difficult thing has been allowing for the discrepancy in sizes of all the bricks I have been using. The base was made up predominantly of previously used 25mm thick heavies (that I got cheap about 10 years ago). It turns out they are shorter than 23mm in length, not by much but enough to cause a slight overhang with my lovely new clean bricks. The chimney section is all being built from other second hand heavies that are pretty variable too.

This image shows the firebox section interior, with hobs and a grate in the floor. All the new clean crisp edged bricks are now being laid dry (without mortar).

...and this is the chamber. On the right you can see the large open throat (with central pillar) towards the firebox, and to the left a chequered flue system to the base of the chimney.
More tomorrow, including making the arch former. The arch an side wall are 26 grade insulating bricks. Once I get that and the firebox finished I will measure up for the metalwork.....oh yes, and the roof.

To the floor

Making the most of this good weather and am interspersing preparing new clay bodies with more work on the kiln. Here it is....

......up to floor level in the chamber. Dinky little thing isn't it? The firebox has a slightly lower floor and I haven't put the grate bricks in yet. The chimney will have a slightly higher floor so front to back it's on a slight rise. Next thing is to build the small arch that will lead from the firebox to the chamber. I'm thinking of making a small catenary arch for that - three bricks wide so there's little restriction between the two. The plan has been rather fluid up until now, so I need to decide exactly what comes next, how I'm going to do it and how many more bricks I am going to need. I'm going to put an arch over the chamber instead of making it a top loader. It does mean that I will be unable to change the chamber height but also that I don't have to much around with kiln shelf lids or welding a steel frame for a fibreboard roof.

Laying down base

Well well - look at this first image. Blue sky! In Britain! I'd quite forgotten how beautiful it is.

I've laid down a 50mm concrete paver base on a bed of sand and set out the floor plan of this kiln.

It's slightly raised from front to back to allow for a grate in the firebox and a small rise to the chamber and then the chimney. As you can see it's quite a small kiln. Large enough to make it worthwhile firing but small enough to allow me to do frequent differing firings.
The corrugated iron arrived today so the next think is to extend the kiln shed.