Cups!

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My second attempt on the wheel resulted in two small cups, which seem to be sitting at an odd spot between cups and small bowls, they seem to be lopsided and thick at the base.

The cups were so lopsided I decided to finish the first two by hand (the middle and far right cups below), carving down the exterior walls with a parring knife, removing excess clay from the thick walls. Partially burnishing one and slip coating the other with the natural clay from Windsor.

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After taking a night to mull it over I set to work trying to figure out why the vessels were forming so lopsided. Was it the home made wheel? something miss aligned or of kilter? was it my inexperience showing? was I holding my hands the wrong way? too much water or too little? It turned out it was none of these. The wonky-ness was coming from the uneven deck! A quick check with a spirit level and a couple of chocks of wood to correct the level and the wonky-ness was fixed! (well, greatly reduced, lets stock the rest up to inexperience, shall we)

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Pit Firing

1: Dig a Pit

  • You can either dig a pit directly into the ground, or build an artificial mound which is considered more stable rather than natural variations in the soil which can affect temperature retention.
  • The smaller the hole the better
  • Optional insulation at base and sides with cinder blocks, rocks, cement or clay

2: Stacking

  • On packed earthen base or alternative foundation as mentioned above, stack dried green ware
  • Consider the distribution of the coals as they fall
  • Do not have pieces touching, as this may encourage breakage

3: Fire Fuel

  • Fill the spaces under, around and on top of pieces with punk or kindling (wood shavings are ideal) this will make the firing more even
  • Build a fire over the top, so the coals can drop down into the pit. Continue until pottery is completely covered by coals.

4: Cooling

  • Cooling is where most breakages happen due to contraction
  • Can take 12 hours or so
  • Remove carefully once completely cool

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Notes and Alternatives:

  • Make sure the pieces are completely dry before firing, if they are cool against your cheek they may need more drying
  • Build the fire in the pit and build up embers before placing clay pieces over top on a rack, some suggest building up and burning down this internal fire three times to heat the walls
  • Wood shavings should be damp, so they smoke and slowly increase in heat rather than burning rapidly, should smoke for a few hours
  • Let cool overnight, remove coals above, allow to continue cooling till clay is cold
  • Excavate SLOWLY
  • Unless glazed in some way these pieces will not be water tight (Bisque only) as with traditional kiln firing
  • Need to read further to see if a second salt firing or slip may make bisque ware fireproof

Notes from Native American art ceramicists Cher Shaffer

 

Dark Age Ceramics of the Hebrides Pt. 2

Chapter 2

Continuation of the Udal excavations lead by Ian Crawford (1963-1976 and 1978-1982). The Udal site contains superimposed settlements from the Iron Age to the Post Medieval period. The site boasts over ten meters of diagnostic stratigraphy with hand made pottery found at all levels, excavation revealed 150,000 pottery shards, which due to low funding was recorded by a single person.

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Archaeologists at work in Udal, 1981

 

1st Strat of Occupation – Iron Age

  • Decorative “Wheelhouse” pottery sherds
  • Very similar to a’Cheardach Mhor and Kilpheder
  • Decorative fillets, incised, applique etc

2nd Strat of Occupation – Dark Ages

  • Cellular homes, slab lined central hearths
  • 2 meters of deposit
  • Decorative bone pins, combs, clay moulds and crucibles
  • Unusually rich in pottery
  • Carbon dating suggests 336 CE – 590 CE
  • Dark age ended by Viking raids and settlement 598 CE – 815 CE

3rd Strat of Occupation – Viking Age

  • Strat levels X, IXc, IXb
  • Stone buildings, rectangle forms. Slab lined central hearth.
  • Final level (IXb) is a dense burn layer, suggesting the destruction of settlement.
  • 50+ bone combs, large crucibles, and a change in pottery
  • Viking arrival is sudden, possibly violent, mid 9th C
  • Level IXc is densely occupied Norse phase,
  • Clay platters

4th Strat of Occupation – Medieval

  • Complete rebuild, new house style post IXb destruction
  • Continuation of hand made pottery