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URL: Plainsman Super Kiln Wash recipe
Click the link below to go to this page
https://insight-live.com/insight/share.php?z=K5hHzDs2Kr
Instead of 50:50 kaolin:silica this recipe uses 80:20 Zircopax:Calcined kaolin. And adds CMC gum to slow down drying, make it brushable, harden it and reduce water requirements.
Related Information
Kiln wash that really works. How?
The shelf on the right has the traditional kaolin:silica kiln wash. Flaking constantly. Sticking to the feet of ware (plucking). A real aggravation. The one on the left is L4001, it is perfectly even. Yet thin. Much more refractory so it has not become brittle. Or cracked. And it paints on beautifully. The secret is four-fold? First: Zircopax (or Zircon) is among the most refractory materials used in ceramics. Second: We mixed it with calcined, rather than raw kaolin. That greatly reduces drying and firing shrinkage. Third: The zircon makes up 80% of the recipe, not 50%. Fourth: CMC gum (via Laguna gum solution) takes on the role of hardener. But it does much more: It also slows down the drying and gives the slurry the consistency of paint (for each application by brush or roller). Click the link below to get the recipe.
Super kiln wash that can be applied with a paint roller
Traditional 50:50 kaolin:silica kiln wash can be a real bummer to use. It flakes, both on drying and after every firing. Pieces of it stick to the feet of ware (plucking). It is not refractory enough either. Shelves need cleaning and rewashing often. Three outside-the-box ideas make this a better recipe.
#1 No raw clay! Strangely, calcined kaolin is better than raw kaolin, it imparts multiple advantages.
#2 No silica. We use zircon or alumina instead, they are more refractory. And we use 80%, not 50%.
#3 We add CMC gum. It is the hardener, it enables a high specific gravity, imparts awesome brushing properties and slows down drying on cordierite and alumina shelves.
The low water requirement and slow drying make this behave more like paint. It can be applied by roller or brush. Coverage is much more even and it does not shrink and crack on drying. Normally the raw kaolin in 50:50 kiln wash suspends the slurry, makes it brushable and hardens it on drying. But CMC gum is way better for the latter two. It is so nice to be able to apply a thin layer of wash even on highly porous shelves (like these alumina ones we make ourselves). Unfortunately, we can't have everything - a down side of this recipe is settling (more information on the recipe page linked below). Fortunately, if used every few days it won't be a problem.
This is not available as a product, we just like it so much we made a label for it!
Links
| Glossary |
Kiln Wash
A high-melting powder applied to kiln shelves to prevent ware from sticking to the shelf during firing. It is also used as a parting agent for to keep elements of fired ware from sticking to each other. |
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