: perkolator - Viewing Profile

i'd say those raspberry red glazes aren't very close to the type of red you're trying to achieve. usually those chrome/tin reds are more of a fuschia IMO, at least that's how mine have always come out. I use the Lana Wilson recipe or similar.

i would love to be able to find a nice copper red recipe since mine seldom come out the "chinese red" (vermillion red) that I've always associated with copper reds. it's always been my understanding that many of these red glaze recipes are held under lock and key so nobody else can replicate them since they are so elusive and require a reduction-firing genius to get them to turn out correctly or be burned off.

Anyone know what the company making Crate & Barrel's ceramics uses for their sweet orange-red glaze? I figure it's commercial. Have no idea how to achieve such a bright color like that, but would like to know!

what's your process for reclaiming clay? how long are you aging for?

when clay dries out, it loses pretty much all of the plasticity and has to start over once reconstituted - so if you're using reclaim that's been dried out and didn't have time to sit in a slop barrel/slake down for a decent amount of time to allow bacterial growth, this could be why. if you're making fresh clay from dry-bagged material, same thing, it needs to "age" and get funky from the bacteria that make it more plastic (due to acetic acid excrement); also there's the issue of the clay particulates not being fully saturated yet if using dry material, which adds to shortness since the particulates lose much of the meniscus of water surrounding them once they soak up this water when it equalizes -- usually mixing a wetter batch of clay will help this a tad.

as for plasticizers, you can add other things besides beer to make it more plastic (beer provide more bacteria/food source). simply adding more clay with organic content (like ball clays) can also help. industry typically uses bentonites/hectorites, VeeGum T, or cellulose/vegetable gums to help modify the body and be more plastic. immediate plasticizers to try are vinegars or epsom salts, both of which I believe change the chemistry making the particles negatively charged/more acidic, essentially flocculating the clay body.

All my Skutt stands are 8" tall. A 1227 kiln sits around 30" to the top of the 3rd ring (under the lid). I believe this is standard size across many brands.

Getting to the bottom of a kiln is hard even for a 6ft tall person. Downside to shorter kiln is not being able to fit much inside obviously. Usually when you get shorter, wider kilns, they have to add in floor/wall elements to compensate for getting heat to penetrate the center of the stack.

I know some artists getting older who struggle reaching the bottom of their kiln, so when I was helping them research the replacement kiln I suggested looking at a front-loading electric (like the new Skutt, Hercules, L&L, Paragon, etc. -- or even one with a "Bell-Lift" system (like those fancy raku kilns where the walls lift up with the cantilever system)

how is your pug mill "ruining" your clay?

Marcia Selsor, on 21 May 2013 - 11:50 AM, said:

I'm not 100% positive since he always had it in a tilt-bin in his lab, not in the original container -- but once I saw him refill and the bag definitely said plaster of paris on the label. Whether or not it had a secondary labeling designating it as investment plaster I cannot say. This was like 20yrs ago and the red label that's on Plaster of Paris was definitely different than today's markings. IIRC, he did pre-heat the plaster mold slightly before casting. Unfortunately He's no longer with us, otherwise I'd just call him up and ask.