Wednesday, February 24, 2016

February at the Old Post Office, (Part One) ... I say "Majolica", you say "Maiolica"

I posted rather infrequently in winter, and I used the excuse of hibernation to explain the paucity of information that was flowing from these virtual pages... Now it is mid summer here, I suspect this excuse has worn rather thin! I could argue that, having emerged from winter slumber, and shuffled into the spring sunshine, a great bear is hardly likely to spend much time blogging... when there is an empty tummy to feed and some seasonal socializing to be done!

Someone did once say I looked like a bear, but at least I am smiling! (Photo by Rhonda.)
Anyway, here we are early one morning in late February, one kiln with the lid propped a little way open in the final stages of cooling, and another waiting for a few glaze tests to be done before it is packed and fired. I am showered and dressed and into my first real coffee of the day, and there is about another hour to wait before the sun comes up.

As usual I have several projects on the go and it is probably easier to give you an overview of them by listing the most recent one out of the kiln, and going back from there. Thinking about it further, I realize I had better do this edition in two parts otherwise it will be toooooo loooong!

Yes, well... a rooster. I made a lino cut, pressed it into wet clay. When ready for glaze firing I painted the rooster green with some copper carbonate, and the other colours were some manganese dioxide and red iron oxide.

I say "Majolica", you say "Maiolica"..
Last week I took a smallish batch of earthenware mugs, two single person earthenware casseroles, and a couple of dishes from the kiln. I enjoyed making these and playing with some majolica decoration - something I haven't done for years.

Some of you who may be reading this are very accomplished at Majolica decoration and have perfected it to a high degree, my own adventures thus far have been very basic, but quite enjoyable.

Majolica is also known as "maiolica", which is probably more correct, and also appears as Talavera in Mexico. The "real thing" was earthenware that had a lead glaze that had been opacified with tin oxide. The decoration was painted onto the unfired glaze with metal oxides, and the firing fused glaze and decoration together.

Majolica these days is more likely to have a borax frit based glaze that has been opacified with zirconium oxide. This practical non toxic glaze will probably lack the "warmth" of the traditional glazes. Modern ceramicists are also quite likely to use glaze stains that are prepared in nearly every colour of the visible spectrum, rather than metal oxides.

For this experiment, I used a commercial white glaze (because I happened to have some), and metal oxides. The metal oxides were prepared according to an article I read by Linda Arbuckle, whose work I have admired for years. I found the article here

I used copper carbonate, for green
red iron oxide, reddish brown
cobalt carbonate, blue
and chromium oxide, for a stronger mid green

(well, I hoped for these colours... but got rather different results!!)

To one teaspoon each of these I added one teaspoon bentonite and one teaspoon frit 4124 (a medium soft borax frit, you may have 3124 or similar).

I also used manganese dioxide, and to one teaspoon of this I added one teaspoon of bentonite and one teaspoon of frit 4110. This frit should help manganese develop a purple brown.

I stirred each of the oxide/bentonite/frit dry mixtures together in small ceramic bowls until well blended, then progressively added water (whilst stirring) to make each mixture a creamy brushable liquid.

I made up about a litre of commercial white glaze with about 1 percent red iron oxide to warm up the "refrigerator white" and a couple of percent of bentonite to help the glaze suspend in the glaze bucket and to give it a less powdery surface when dry and unfired. I glazed the pots by pouring and/or dipping them in the commercial white glaze, then decorated the glaze when it was dry. In spite of the bentonite, the glaze was rather powdery, and really needed something more to harden its surface. If I were to use this particular glaze again I would look at adding a gum such as CMC (carboxymethylcellulose) to bind the glaze together.

In spite of the powdery nature of the glaze, I managed to decorate without too many problems, although the chromium oxide tended to pull off the glaze when dry, I may have applied this a little too thickly.

I enjoyed just letting the brush dance along the surface, and improvising simple blobby patterns.

The work looked like this before firing...

Rather different afterwards.

Green: copper carbonate was an OK copper green but did not "sing".
Blue: cobalt was grayer and more subdued than expected.
Purple brown: manganese was more of a pale mid brown rather than purple brown.
Red brown: red iron oxide gave dark charcoal brown.
Mid green: chromium oxide gave brown rather than green.

cobalt carbonate for blue and chromium oxide giving brown thin lines
mid brown manganese dioxide "blobs, dark red iron oxide lines, and copper carbonate green "blobs"

None of the above were "wrong" or "faults" as such, but just showed what particular oxides will look like when put over this commercial glaze. If I were to continue using this glaze in future, I would have to learn to work within its limitations, this is the case for any glaze. Every one has a different personality. One problem with using commercial glazes (this one was Abbot's White), is that the manufacturers can be cagey about releasing information about what ingredients have been used to make the glaze, it is difficult then to know how they will affect metal oxides or other glaze materials. You just have to test and see what happens!

Anyway, I enjoyed this little majolica excursion, and will do more. I will make up some other white glaze bases for my next test.

A single person casserole
That rooster dish

To my delight, as I write this, I have also discovered a blog that Linda Arbuckle kept between 2012 and 2014, it seems a wonderful resource of information for anyone that is interested in decorating ceramics Thank you Linda!


gz said...

having fun!! nice mugs

Peter said...

Hi Gwynneth,
Lovely to hear from you!

mugmkr said...

I love those mugs!

Robert Harris said...

I am a long-time Lurker, prompted at last to respond.

I once was told that the difference between majolica and maiolica is that one is reserved for the real Italian stuff and one is what everyone else does. Not sure if that's still true, merely a museum curators definition or a figment of my imagination! And I can't remember which was which!

Secondly ... tin is expensive, but boy does it make a difference - including to colour responses. I have read - but not tested - that using 2-3% tin along with 5+% Zircopax is sufficient to make things a bit singier.

I also read Hannah McAndrew's blog (which I think you do too) and saw a delightful youtube video which she posted in memory of Barry Brickell. I se that he lived somewhat near Dunedin and wondered if you knew him or not.

Peter said...

Hi Owen (mugmkr),
Good to hear from you, thank you for the encouragement! You make wonderful mugs yourself!

Hi Robert,
Thank you so much for following the blog and for writing in, it is good to hear from you. It is interesting the use of "majolica" vs "maiolica" and also how techniques like that can find new life and evolve in unexpected ways when they are taken up in other parts of the world. Raku is a good example of that.

Tin oxide, magical stuff!! Your remark is timely as I took some glaze tests out of the kiln this very morning of an earthenware glaze I had made and a zirconium opacified version of the same, both had worked well, but I did mutter to Laura that I thought I should try substituting tin oxide for some of the zirconium as I was missing the lovely red "break" that tin will often give where a glaze is thin over an iron oxide bearing body. I'll do a line test progressively swapping tin for zirconium and see how much tin is needed for the magic to begin!!

I'll catch up with Hannah's blog, it will be good to see the video. A few years ago we visited Barry Brickell's Driving Creek Pottery in Coromandel NZ (a long way from Dunedin unfortunately!!). We had a lovely time there and did briefly meet the man himself. We also saw him giving a demonstration on the wheel in Dunedin at the Art School about 2 years ago. There was a wonderful exhibition of Barry Brickell's work that came to Dunedin last year and it was very refreshing to see someone working with mostly unglazed earthenware clay, and allowing flames and smoke to do the decorating.

Michèle Hastings said...

I love those colorful pots! My favorites are the little casseroles.

Peter said...

Hi Michèle,
Thank you for the encouragement! We'll be trying out one of the casseroles really soon!

Linda Starr said...

my word Peter those are wonderful, have you ever made a tangine ? a very similar shape to your personal casserole

Peter said...

Hi Linda,
You are right about the shape of the casserole, I think it should be called a cassegine or tagerole! I have made a few tagines before, and should do a few more as they are fun to make and are a nice way to present food to the table too!

Armelle Léon said...

Hi Peter,

Your decorations are very nice and I like very much your free style, nice roster too :-)

Peter Gregory said...

Hi Armelle,
Good to hear from you, more roosters are in the kiln cooling down as I write!!! :-)