|Monthly Tech-Tip |
Tony Hansen is the author of Digitalfire Insight, Digitalfire Reference Library and Insight-Live.com, he is a long-time potter, ceramic lab-technician and body and glaze developer.
Tony Hansen is a potter, researcher, author, software engineer and developer of ceramic body and glaze recipes. He has used Digitalfire Corporation as a medium to distribute his software and knowledge products. He has had a long and close association with Plainsman Clays, they have provided him with a well equipped lab and studio and free use of anything in the factory and warehouse (hundreds of different kinds of clays and materials). His accomplishments include:
I love making pottery, but I love the technical side more. I searched for all the test specimens in this load of cone 10 reduction ware first, then pushed it back in and forgot about it. For three months! I really anticipate the test results (I am developing and adjusting many of bodies and glazes at any given time). The data and pictures for them go into my account at insight-live.com, it enables me to compare the chemistry and physical properties of recipes and materials side-by-side. That teaches me which roads to abandon and which ones to pursue. My last kiln went back in for six weeks, so things are getting worse!
This bowl was made by Tony Hansen in the middle 1970s. The body was H41G (now H441G), it had large 20 mesh iron stone concretions that produced very large iron blotches in reduction firing. Luke Lindoe loved to use these clays to show off the power of the cone 10 reduction firing process that he was promoting in the 1960s and 70s.
It has morphed into a webapp, reflexive and menu-driven (based on Twitter Bootstrap). It now employs permanent URLs. And pages have logical, and hierarchical URLs (e.g. digitalfire.com/oxide/cao, digitalfire.com/material/feldspar). It correctly forwards 5000+ old URLs. Terms from the glossary automatically hotlink throughout (as do code-numbers for recipes, tests and firing schedules). The search field in the menu bar is area-specific (or all-area at digitalfire.com/home). Still no ads and no tracking. The UI displays from server #1, it calls the database API on #2, the email system on #3, media from #4 and insight-live.com from server #5! So it is super fast, flexible and expandable. There are new areas (e.g. projects, pictures, typecodes). Media displays better. Every page still has a contact form, so you can ask any question anywhere. What till you see what's coming!
The outside glaze on this cone 10R mug (made of Plainsman H550) is simply an Alberta Slip:Ravenscrag Slip 50:50 mix with 5% added Ferro Frit 3134 (the Alberta Slip is calcined). This produces a stunning celadon with great working and application properties. Inside glaze: Ravenscrag Slip 90%, talc 10% (a matte having an extra ordinary silky texture). Learn more at ravenscrag.com.
Much effort is expended at Plainsman Clays to develop good transparent base glazes. Far left is a white cone 6 porcelain made from New Zealand kaolin, a super-white-burning bentonite, feldspar and silica. P300 is a kaolin-only cone 6 whiteware. M370 is a kaolin-ball clay whiteware. The P300 and M370 recipes contain feldspar, silica and bentonite also. M340 is a buff stoneware, it is made from locally mined stoneware clays with no additions of feldspar or silica or any refined clays.
These cone 6 mugs use an 80:20 Alberta Slip:Frit blend inside and out (the outside one has added rutile). Made around 2014. The incised wheat decoration as a dead giveaway that the mug is made by Tony. He has made this type of mug for decades and there is a good reason: continuity of testing. By making the same kind of ware each time he tests a clay, going through the same procedures he has done a thousand times, he can more easily spot differences in the way they perform.
This was typical of many made during the 1980s and sold in a gallery in Brandon, Manitoba. Tony was inspired by the work of John Porter and emulated many of his techniques. This is a dark burning iron stoneware clay, H440, fired at cone 10 reduction.
He was the founder of Plainsman Clays. My dad had just built the Plainsman Clays factory for him and I began working there in 1972. He was a well known artist potter and sculptor at the time, having come out of the pottery production industry in the area. He got me started along the fascinating road of understanding the physics of clays. He was a true "plains man", interested in the geology (notice the skulls, these inspired the Plainsman logo). He got me started doing physical testing of raw clays (that he was finding everywhere). I was blown away by the fact that I could assess a completely new material and judge its suitability for many types of ceramic products and processes by doing the simple physical tests he showed me. It got started writing software to log the data for that back in the 1980s, that eventually led to digitalfire.com and Insight-live.com.
This was used until about 2000. Any numbers relate to the type of clay being used (often a test). In this case, the body is a test mix of Plainsman H431. The year is 1981.
Tony's lab work area of mineral and chemical powders for mixing test glazes and clay bodies. Stoneware and earthenware glazes are made from dozens (even hundreds) of commodity industrial mineral powders.
A book published by Tony Hansen (no longer available). It explained why we need to think about materials (and the bodies and glazes made from them) as more than just powders. They have physical, chemical and mineralogical presences, a knowledge of which provides better control in ceramic production. This was the first widely read book to show how, using this knowledge and glaze chemistry, readers could solve all sorts of problems. It showcased the real value of the oxide viewpoint in ceramics and explained how to use Digitalfire Insight and Foresight software in each scenario. From 2000-2014, the book was used as courseware in universities around the world. In 2015 it was superseded by the online Digitalfire Reference Library (which is a superset of its content).
The clay is Plainsman H431. Fired at cone 10R. Tony learned how to make these bowls from John Porter in the early 1970s. They were glazed on the inside with the rough, bare clay surface on the outside. Decoration was done by a wax resist technique. The glaze is a silky dolomite matte with rutile and a little cobalt added for the powder blue color.
Any numbers relate to the type of clay being used (often a test). In this case, the body is Plainsman P300. The fluted foot ring (for better draining in the dishwasher) is also a tell-tale sign the mug might be made by Tony.
Digitalfire Reference Database
This is the traditional ceramics reference website that couples with your account at insight-live.com.
YouTube channel for Tony Hansen
Database software for DOS made by Digitalfire from 1988 until 2005 and was used to by ceramic technicians to catalog recipes, materials, test results and pictures.
A database website where potters and ceramic technician account holders enter their recipes, materials, pictures, test procedures, firing schedules, etc.
A downloadable program for Windows, Mac, Linux for doing classic ceramic glaze chemistry. It has been used around the world since the early 1980s.