The only way you will ever get the glaze you really need is to formulate your own. The longer you stay on the glaze recipe treadmill the more time you waste.
The traffic in glaze recipes has had a net negative
effect on functionalceramics in education, hobby, and industry. Books
and the internet are filled with recipes that are illogical and
emphasize appearance at the expense of safety, practicality, or cost.
'Affairs' with these 'naked' (undocumented) recipes have left many
numbed regarding their accountability and even ill equipped to
recognize true quality. This trade in recipes is fostering a culture
that runs counter to the idea of 'understanding' and controlling our
materials and recipes, it breeds ignorance of oxide and material
sciences and the true nature of the ceramic process. It deludes many
into an 'easy-fix' mentality that seeks 'foolproof' solutions that end
up being blind allies that waste years and teach nothing. Implied
'ethics' suggest that the traffic in recipes be accompanied by
documentation to prove givers conscientious and by critical analysis
and testing on the part of recipients willing to 'understand' and
adjust. Weak, leachable, difficult-to-clean, crazed, shivered,
leaching glazes hurt the reputation of the pottery and ceramic
industry. It is time that a 'want-to-know-why' mindset toward
formulating and adjusting glazes on the oxide and material level is
fostered in students. It is time that a stigma is attached to joining
the 'illicit trade' in recipes and using trial-and-error
bull-in-a-china-shop approaches to glaze formulation.
We recommend a 'base glaze with variations' starting model. As your
understanding of a base glaze improves over a period of years you can
develop the ability to identify its mechanism and learn to
transplant them into different bases. In this way you can minimize the number of base
recipes you use. In addition, as you improve each base (e.g. its
application properties, fired harness, fit adjustability, etc) all the
variations based on it will inherit the improvements.
In education and pottery circles the trade in recipes has encouraged a
'roulette wheel' approach to choosing glazes and in big industry there
is a brain-drain toward suppliers and consultants while many
manufacturers are becoming more and more helpless. At Digitalfire
Corporation we personify these dangerous trends and attitudes as 'The
Dragon'. The dragon wants you to believe that casual potters are
exempt from technical concerns. He fosters blissful attitudes that
keep us on an endless treadmill of glaze recipe experimentation and
disappointment or on suppliers that lack a connection to unique
circumstances and customer specific problems. The dragon wants us to
think that glaze chemistry is too complicated and too much trouble.
The Formula Viewpoint, Key to Taking Control
Chemistry, that is, viewing your glazes as formulas of
oxides rather than recipes of materials, is an invaluable tool to deal with
things like hardness, strength, porosity, leaching, thermal shock
resistance, chip resistance, glaze fit, color compatibility, of your
functional ware. A typical formula contains eight or so oxides and it
takes a lot less study to figure out what these contribute than it
does to figure out what 100 different materials do. Glaze software,
like INSIGHT, provides the simplest way to work with glaze formulas.
G1214M Cone 5-7 20x5 Glossy Base Glaze This is a base transparent glaze recipe developed for cone 6. It is known as the 20x5 or 20 by 5 recipe. It is a simple 5 material at 20% each mix and it makes a good home base from which to rationalize adjustments.