It’s been the usual descent into summer’s competing priorities: family holidays, working on the house (exterior wall and windows) and trying to keep up with my ceramic work. I have been lucky enough to have found a chance to re-visit my friends up on Clee Hill, to dig some more clay. I’m also very grateful to the kind people at Hansen Quarries up on Titterstone Clee Hill for giving me a small bucket of “dust” to experiment with from their Dolerite quarry. Unfortunately, due to health and safety restrictions, I’m not allowed to go and collect this myself – but they gave me a small sample from their finest grade aggregate and I washed the dust out through a 100 sieve.
It’s been great. The Clee Hill clay fires to an amazing purple / red at 1260 degrees C in my electric kiln (oxidising), and the glazes I have made with the quarry dust, local clay and wood ash (mixed 33% evenly) have produced a beautiful, glassy black (where thick) breaking to brown “tenmoku” like glaze that works well with the clay. Other glazes I experimented with have crawled, flaked and pin-holed – especially as I make the move away from double firing (i.e. bisc and glaze) to single firing. The Clee Hill Glaze works well with no additives etc. – which is great. To set off the two colours, I have researched which other minerals were dug over Clee Hill and found that copper seams run through the hills amazing mix of dolerite, limestone, coal…. etc. I have used a zircon silicate base glaze (that I have used a lot from Stephen Murfitt’s invaluable Glaze Book) with 2% added copper carbonate to create a turquoise that seems to work well…..