[Clayart] kiln wash

Robert Harris robertgharris at gmail.com
Mon Sep 27 14:55:42 UTC 2021

I'd never use silica in a Kiln wash at Cone 10. Too likely to enter the
melt with any drips of glaze (or increase plucking with porcelain). I've
heard of people using it successfully at lower temps though.

I'm with Mel, I make up a very thin slurry of Alumina hydrate and wipe that
on. (Even on silicon carbide shelves, a small amount of water that rapidly
evaporates is fine. It's only when the water really soaks in that it's a

50:50 EPK/Alumina hydrate is a pretty standard Kiln wash. The reason to
calcine the EPK is so that it remains somewhat powdery and doesn't fire
into a hard coating that flakes off in large chunks. Also ... apply like a
thin wash, not a coat of plaster! You don't need to cover up every single
atom of the shelf surface. (No stage, pancake, make-up here, please!)

On Mon, 27 Sept 2021 at 08:36, mel jacobson <melpots at mail.com> wrote:

> I have had several folks ask for kiln wash recipes..theory.
> Basically it is combinations of Alum/hydrate, China clay, Silica.
> Depending on your need, you want to experiment with combinations
> that do not flake off.
> Often folks will calcine the epk.  Robert gave us a Zircopax and calcined
> Kaolin idea.  The theory is, using a combination of ingredients that do
> not melt.
> No fluxes please.
> I have never used wash.  If I have some porcelain, or other clays or
> glazes that
> run fast, I dust the shelf with alum/hydrate, or fine sand.
> mel
> website: www.melpots.com
> www.melpots.com/CLAYART.HTML
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