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Tony Hansen's Thousand-Post TimeLine

I am the creator of Digitalfire Insight, the Digitalfire Reference Database and Insight-live.com. ... more

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Transparent glazes often work poorly on dark stoneware bodies

Transparent glazes often work poorly on dark stoneware bodies

These are fired in cone 6 oxidation. They are all the same clay body (Plainsman M390). The center mug is clear-glazed with G2926B (and is full of bubble clouds). This dark body is exposed inside and out (the other two mugs have a white engobe inside and midway down the outside). G2926B clear glaze ... more

Sunday 2nd December 2018

A cone 6 clear glaze plus iron vs. Alberta Slip amber base

A cone 6 clear glaze plus iron vs. Alberta Slip amber base

These two mugs are made from a dark red burning stoneware and fired in a cool-and-soak firing schedule. A white engobe (L3954A) has been applied on the inside and half way down the outside. Both are glazed inside with G2926B whiteware transparent glaze. The outside glaze on the left is the same ... more

Sunday 2nd December 2018

Testing your own native clays is easier that you might think

Testing your own native clays is easier that you might think

Some simple equipment is all you need. It is amazing how much you can learn from characterizing a body or clay material. You need a gram scale accurate to 0.01 grams (very inexpensive at your ceramic supplier). A set of callipers (again, not expensive these days). Some metal sieves (expensive, so ... more

Saturday 1st December 2018

Printing a prototype propeller for my Lightnin lab mixer

Printing a prototype propeller for my Lightnin lab mixer

An example of how handy the ability to print in 3D can be. The worn-out stainless propeller costs $300 to replace. But the size and pitch of the blades is not ideal for the work I do. I print them in PLA plastic, this enables experimenting with different sizes and pitches. When one works well then I ... more

Saturday 1st December 2018

A must-have: Laboratory variable speed propeller mixer

A must-have: Laboratory variable speed propeller mixer

If you are at all serious about testing glazes and clay bodies, you need one of these. There are other methods, but nothing else comes close to this. It is the most valuable and frequently used tool in any ceramic bodies and glazes testing lab or classroom. These are expensive new, this Lightnin ... more

Saturday 1st December 2018

CMC Gum is magic for multi-layering, even for raw Alberta Slip

CMC Gum is magic for multi-layering, even for raw Alberta Slip

The glaze on the left is 85% of a calcine:raw Alberta Slip mix (40:60). It was on too thick so it cracked on drying (even if not too thick, if others are layered over everything will flake off). The solution? The centre piece has the same recipe but uses 85% pure raw Alberta Slip, yet it sports no ... more

Thursday 29th November 2018

A problem with super-white porcelain mugs

A problem with super-white porcelain mugs

These are made from Plainsman Polar Ice translucent NZ porcelain. The one on the right was used in the coffee room of the plant and washed between uses in a common manner (which is: not very much!). The stains are obviously not nearly as visible on a stoneware mug.

Monday 26th November 2018

Just enough iron in this celadon to highlight the design

Just enough iron in this celadon to highlight the design

There is only 0.35% iron oxide in this recipe, as much as ten time less than normal. But this is just enough to provide a darker shadow (where the glaze is thicker) at the edges of the design. This is porcelain fired at cone 10 reduction by Janel Jacobson.

Friday 23rd November 2018

Gum does not work in a glaze if an important ingredient is missing

Gum does not work in a glaze if an important ingredient is missing

These brush-strokes of gummed glaze are painted onto an already-fired glaze. Gummed glazes can do this, they will adhere and dry without cracking. And dry hard and resist washing off. Brush strokes hold their character. The brown glaze has 1.6 specific gravity (SG) and about 1.5% CMC gum. The white ... more

Friday 23rd November 2018

Feldspar applied as a glaze? Yes! The way I did it will change how you glaze.

Feldspar applied as a glaze? Yes! The way I did it will change how you glaze.

Custer feldspar and Nepheline Syenite. The coverage is perfectly even on both. No drips. Yet no clay is present. The secret? Epsom salts. I slurried the two powders in water until the flow was like heavy cream. I added more water to thin and started adding the epsom salts (powdered). After only a ... more

Friday 23rd November 2018

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What people have said about digitalfire

• I love the site. I use it all the time at the Clay Business, and I feel like I have not even touched the surface.

• I would love to take a trip inside of your brain. I am sure that it would be a fantastic light show.

• I have a background in Geology (BS-1973-New Mexico Tech), and with a few other degrees here and there - and have been doing quite a bit of Pythoning, and hanging-around my wife who does (I think (but then, of COURSE I am biased)) terrific pots... I am always interested in what she does with glazes (especially when I see the mineral-names from my Geology days on the bins in her studio... BUT - as an "engineer", sometimes I want 'more' knowledge - and I find your web-site VERY VERY good at that, it tells me a lot of things - gives me 'value added' and 'information' that I haven't found elsewhere! Especially when I think about 'geo-chem'.

• omg i just discovered your page this is like breaking bad for ceramics, learning how to cook. this is a great page thanks !

• Your resources are truly amazing and as an ex electronic engineer (now a potter), I really am impressed with your analytical approaches. Your site is almost a complete college level course on pottery (less the throwing & handbuilding). Thank you for your wonderful contributions.

• I have read just about all your articles on Digitalfire and use your software, really appreciate the wealth of knowledge and testing you bring to ceramics.

• Again, thanks for being such a resource to potters over the years!


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What people have said about Insight-Live

• I'm glad I was of some small service. Your whole venture is a marvel. All the best as we go forward.

• Love the post (about leaching in glazes). I am the bad guy on Facebook ceramic because I always bring up this subject. So sad.

• The knowledge and information you share on digital fire is a rare gem on the internet. I greatly appreciate your writing style. To the point and full of facts. I am wanting to be more active in my glaze creation and begin to make my own glazes. This, to me seems like a huge step away from the safe and what I know of the glazes I have been working with.

• It's very impressive work you do. Thanks you for providing it.

• Please continue this brilliant service!

• Absolutely love the insight-live web app.

• I want to thank you for creating all that extensive and wonderful material in Digital Fire and Insight Live. I have started with the process of creating my own glazes a little bit more than a year ago, process that I found exciting and challenging and thanks to your websites it has been a lot easier!


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