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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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What is the temperature difference between these two cones?

Four degrees F. I was consistently getting the cone on the left using a custom programmed firing schedule to 2204F. However Orton recommends that the tip of the self supporting cone should be even with the top of the base, not the bottom. So I changed the temperature to 2200F and got the cone on the right.

Wednesday 24th July 2019

Cone 6 Fluid-Melt Transparent Glaze - Jackpot!

In 2015 we did a project comparing common cone 6 fluid-melt base glazes, picked a favourite (Panama Blue) and fixed it's slurry issues and crazing. Fluid-melts almost run off ware when applied thick, but they host stains & opacifiers to produce super-gloss, super-brights. That recipe, G3806C, has ... more

Monday 22nd July 2019

Sourcing Li2O from spodumene instead of lithium carbonate

Lithium carbonate is now incredibly expensive. The glaze on the left employs it. But I was able to source the Li2O from spodumene instead. Spodumene has a complex chemistry, but the oxides that it contains (other than Li2O) are those common to glazes anyway. Using my account at insight-live.com, I ... more

Monday 22nd July 2019

Tin Oxide is expensive, do not waste it by not mixing well

This is a cone 04 glaze on a terra cotta body. Two 300-gram test batches were made. Both have 5% tin oxide added. The one on the left was high-speed propeller-mixed for 10 seconds on a closed container. That was not enough, small agglomerates appear as white specks floating in the glass. The one on ... more

Saturday 20th July 2019

The difference propeller-mixing a glaze can make

The glaze has 5% added titanium dioxide. These were fired at cone 6. The titanium in the one on the left remained agglomerated, it did not disperse in the slurry during hand mixing (the agglomerates can be seen as white particles floating in the glass). On high-speed propller-mixing the effect on ... more

Saturday 20th July 2019

CMC gum solutions can go bad

That is why glazes containing CMC often need a biocide if they are going to be stored for extended periods. We made this one. The gallon jar of Laguna gum solution sitting next to this did not go bad, that means they have added some sort of anti-microbial agent.

Saturday 20th July 2019

This flow tester proves the colorant is not fluxing or bubbling the glaze

These glazes are the same (G3806G), except the one on the right has 3.5% copper carbonate added. Copper is commonly thought to flux glazes, making them melt more. But in this case, the clear base is running just as much as the stained one. And I was suspicious that the micro-bubbles in the glass ... more

Saturday 20th July 2019

This cone 6 black glaze looks glossy until placed beside the cone 04 one

The cone 6 one is on the left, it contains about 25% frit. Both are colored using a black stain. That low fire glaze on the right has a high percentage of frit, likely more than 80%, that is the main reason for the beautiful surface. Frits are really fantastic, and standard practice in industry. ... more

Saturday 20th July 2019

Lemon Leaching Test on a Copper-containing Glaze

This was left for 24 hours. Wrapped in stretch wrap. Then the surface of the glaze was inspected under a lamp to detect any differences between the lemoned and non-lemoned surfaces. Lemons are highly acidic. This glaze passed because the base recipe, G3806N, was methodically developed so that it has plenty of Al2O3 and SiO2 (in the fired chemistry) to build a stable glass.

Saturday 20th July 2019

A glaze and underglaze are flaking off. Why?

At low temperatures glazes are not stuck on nearly as well as for stoneware and porcelain. One of the ways to compromise the bond is to put a layer of refractory material, for example certain underglazes, between the body and glaze. It is kind of like painting something that is dirty, the paint ... more

Monday 8th July 2019

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What people have said about digitalfire

• I have been in the pottery business for 52 years, Pemco use to be 10 miles from us. Your advise on solving our glaze problem worked perfectly and you explained it so well. I have had this problem for 7 years, re-firing lots of ware. Pemco guys and Pfaltzgraff Pottery glaze dept. told me different recipes but it never solved the problem. None of them talked about firing cycles. Tony, how did you get so smart? God has Blessed you.

• I always visit this site, found very helpful to make my own ceramic composition and now I need your software to use for advanced ceramic.

• I have only been involved with ceramics and glazing for about a year now, and I'm hungry for knowledge. The wealth of information you have on your site and in your products has just been great.

• We have been aware of your company and website for many years and see it as a model in its approach to educating makers about the processes involved in making/drying/firing. You teach them to take responsibility for their work process rather than blaming the product.

• Just wanted to share the good news with you. Couldn't be doing it without all the help you have given us over the years!

• Tony Hanson is like the person that is always waiting to answer my questions. He is very thoughtful and quick with response. I wish he was my neighbor.

• Also, as a side note, this website is an excellent resource and I appreciate the fact that all this info is available on the web! Not only that, but I have found the information to be accurate, dependable and thorough, which is difficult to find anywhere.


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What people have said about Insight-Live

• Looking at your website, I have no doubts that there is no other person that would be so dedicated to the subject as you. It is a fact that you have a truly unique knowledge of how things are done, the materials and chemistry being used in such processes. Frankly, I do not complement people and their work easily but you are one of a kind person with some divine dedication to the technology. There are very few people like you and that is a fact. I just spoke with several so-called ceramics, frits and glazes experts and I have to say that they had somewhat limited knowledge while you cover incredibly wide spectrum of all affairs involved in to working with all those great materials.

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

• Anyway I thank you for your efforts in putting together this wealth of ceramic science in this accessible manner.

• I have to say as the subject says i am completely blown away by the amount of valuable information I have just taken in over around 4 hours or reading through your vast content and watching your videos on youtube! I am now a big fan and will for sure sign up with an insight live account as soon as I can!

• Hey Tony, just like to say thanks for your fantastic site as it has been the best reference guide for my helper and I.

• I love insight BTW. I have been showing everyone at Alfred how easy it is to do UMF while comparing two recipes next to each other. The up and down toggles make it easy to understand cause and effect. They are also impressed how easily i can switch between my computer and smartphone and maintain all my work and recipes. BTW I just love insight. It has changed my experience and knowledge of glazes drastically.

• Thanks for doing the timeline. I’ve told you before but it never hurts to say it again, this is great stuff and I get so much info from your posts. Extremely valuable!


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