IMG_1196.JPG136.75KB2 downloadsIMG_1197.JPG174.98KB0 downloadsMy adventure for the summer is helping a fellow potter rebuild her salt kiln. Today was destruction day -- taking down the old kiln. Our merry band of four plan to start constructing the new kiln in mid-July. Over the past two years, I've been helping on kiln maintenance (in return for firings) and trying to shake out some design bugs from the previous rebuild. The old kiln only had about 20 firing on it, but was showing structural issues, brick wear and some design problems that, try as we might (and with some great advice and suggestions from Mark C. and Neil E., just could not overcome. Great learning experience - I've never done kiln construction before. In addition to our merry band, we are getting advice and consultations from Will Baker in NC -- a master kiln builder. The fun has begun.
Vase in foreground is Standard 266 clay (dark brown) with white Bringle slip brushed on and wiped off of from high spots. Soda ash wash applied before firing. Feldspar inclusions. Cone 6, oxidation. Rear vase is Laguna Dark Brown clay, wood fired, cone 10, reduction.
Those are beautiful vases. I love the dark look on the top part of the wood fired one. Brilliant.
It sat behind the stack and on the floor between the two chambers; the top part got the flame, the bottom part did not as the flames exited the flue between the wood and soda chambers at that height. All a matter of placement.
Laguna offers a sample pack of clays (about 4 or 5 lbs per sample) -- your local store will have to special order them, but it is way to try a lot of different clay bodies without going for a full 25 lb. bag.
I don't know if this is what mudwoman is looking for, but that is an intriguing tree-bark texture. It is a little like Sodium Silicate crackle technique but seemingly more responsive to the brushed on thickness of the porcelain slip. I'll have to add that to my wish list of things to try.
thank you so much for your kind support! I wonder if there are any online courses on glaze chemistry I have been reading some articles about how glazes work, but I feel I need help answering all the questions to understand it properly
Amaco suggests a bisque at cone 04 and glaze at cone 05, although it appears you can fire the clay as high as cone 3. You can put you underglazes on at either leatherhard or bisque; I prefer leatherhard as it reduces the potential for the glaze application smearing the underglaze.
So this leaves me to wonder if the clay is fired to maturity at this temp.? One firing chart I was looking at said 04-1 lowfire clays mature.So a bisque at 04 and glaze at 05 leaves me to wonder if the clay ever fires to maturity.
At cone 05/04, no where near maturity . . . nearly 14% absorption rate. You might get maturity at the top firing range -- cone 3.
From Amaco: Wider firing range - from Cone 04 to Cone 3 Resists crazing - low moisture expansion Shrinkage: Cone 04, 6.3% Absorption: Cone 04, 13.7%
Consider refiring one piece in a bisque load; see if that smooths out the blisters. If it works, that is fine; if not, nothing lost. But, it is better to just trash the items and make new ones; consider it a learning experience (and we all have similar ones).
bruce, i thought the same thing and used some slip made with Danish White, a cone 8 clay. made probably 15-20 separate colors. applied it to cone 6 clay. worked fine until it began to peel off the finished pieces in some places. it hurt to get rid of all the colors.
Not familiar with Danish White. I've used Helios Porcelain from Highwater with no problems, including mixing it with Mason Stains. Am trying some Standard 130 that I was gifted from another potter.
Underglazes usually have a flux and binder added to them to help adhering to pots; stains you generally have to add some type of flux or binder (borax frit, gertsley borate, borax, etc). Apply to leatherhard, bisque, then glaze.
Just the pot . . . anything else in the picture detracts from the pot. You want them looking at the pot, not an egg (large, medium, extra-large, free-range, or other), a dime, a business card, whatever. You use rulers in crime scene photographs, not pottery photographs.