Happy New Year! A Cone 9 - 10 dolomite matte glaze for you to try!
I did try to get this card finished and sent away on Christmas Day, but it didn't quite happen, so here it is now as a Christmas/New Year thing.
At this time of year it is usual for people to drop in! We were delighted to meet up with Gwynneth and Vic (The Pirate) who I have read about for several years now on "Ook?!" Gwynneth's blog. Gwynneth is a very experienced and accomplished potter and does lovely linocuts as well, and Vic is a retired aircraft engineer. They are currently in New Zealand intending to compete in cycling events at the Masters Games and were able to travel far enough South this time to come and see us.
It is lovely to meet other bloggers "in the round" as it were, and we made sure that we remained comfortably three dimensional by having an evening out with them and feasting together on yummy wood fired pizzas at "Salt and Sugar" the Karitane General Store in the next village!
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| Gwynneth, Laura and Vic |
Christmas, and the week or so after it, is an odd tumble of days which quickly lose their comfortable labels of Monday, Tuesday, Wednesday and the like, and today, which my calendar informs me is a Tuesday, really feels like Saturday because it is New Year. In spite of the uncertainty, I have managed to get a glaze firing through the electric kiln and should have some new bowls to put out in our little gallery tomorrow, all going well!
Recently I was pleased to rediscover one of my gazes that I had developed in 2014, a dolomite matte glaze that was intended to be a useful substitute for an old faithful glaze that I had used before when I could still get Cornish Stone at a sensible price... and "proper" Cornish Stone, not the less interesting substitute that you get these days. Real Cornish Stone from Cornwall UK was a fascinating material. A complete high temperature glaze in itself, this natural material contained the glass former silica, the stabilizer alumina, and fluxes sodium, potassium and calcium, with the interesting addition of a trace of Fluorine (if you were lucky!). Quite a nice high temperature clear glaze could be made from it by adding just a little more flux, such as 8 - 12 percent calcium carbonate.
By studying the chemistry of the various natural materials we use for potting it is possible to make reasonable substitutes in some cases, but they are never really the same as the natural ones, that doesn't mean that they are necessarily inferior, just different, rather like family members that look much the same, but have unique personalities!
At the time that I made the glaze, I did not do a great deal with it other than use it on a few test pieces, and 2 liters sat for 4 years in a bottle, not coming to any harm as such, but looking rather neglected! At the time I probably found the glaze OK, but not hugely inspiring on the rather iron rich stoneware clay I was using. Now I am using a porcelain body I am really delighted with the result.
Here is my Dolomite Matte recipe. This is a cone 9 - 10 glaze and I have only tried it thus far in oxidation, but suspect it will perform OK in reduction too. Best on porcelain or white stoneware. Stores well!!
Soda Feldspar 25
China Clay 25
Silica 20
Dolomite 15
Potash Feldspar 10
Whiting 5
Talc 3
Total = 103
Happy New Year to you all!
Comments
Love the fishes.
Happy New Year to you and Laura
It certainly is fun to meet with bloggers in addition to the exchange of comments and messages, we have some lovely memories to treasure of such times.
We are actually having the occasional warm summer day here now where we get almost to 30 degrees outside. I am enjoying the relative coolness of our old building on those days, it really is nice in my studio then where we probably reach the low 20s. I suspect those are more like winter temperatures for you!!! :-)
Lovely to hear from you all the way from sunny Auckland! Thank you so much for your encouragement. More bowls are drying on my drying shelves as I write. I am enjoying the brush decoration, something I haven't done much of for a long time, and it is really good fun improvising fish designs.
It's lovely when blog contacts turn into meetings with actual people. I used to write a blog about the house we restored in Sydney and made a couple of good friends from doing that.
The bowls are lovely and I thought I'd give the glaze a go (I've just made up a quantity of the de Boos flecky green). Could I ask whether the dolomite matte is translucent or opaque (a glazer could tell from the ingredients, but I'm not a glazer!) and whether you think colours could be added to it, either stains or the usual coppers etc?
Whilst browsing glazy the other day I saw several of your recipes there, all fully attributed to you. Nice to see them getting around.
It certainly is nice to meet actual people, the internet can make the world a more friendly place after all!!
Do give the dolomite matte a go. You will probably find the glaze almost opaque, but not completely so. It does not have opacifiers such as zircon, or tin oxide, but the nature of a matte glaze like this is to be composed of thousands of tiny crystals which effectively scatter the light and make it look "solid" rather than glassy and clear.
I have not experimented with adding colours to this glaze as yet, because I haven't used it a great deal, but it will probably respond in a similar way to other matte glazes that have magnesium and calcium. As it is a matte glaze it would be best to aim for pastel shades rather than strong colours.
These are all guesses, but.... Cobalt blue will probably give a slightly violet shade of blue. On its own chromium oxide would very likely give brown, but could be used in small amounts of about 0.5 percent to modify copper or cobalt. I suspect that 1 - 2 percent iron oxide may give more of a pale yellow-brown, and 1 - 2 percent copper carbonate a pale, but slightly dull, green.
Do try it and let me know how you get on! :-)
I do like what glazy.org are doing, it is a most useful site, and... I must start to put some glazes up there myself. It is nice to see some of mine there already.
Best Wishes,
Peter
Very nice to hear from you. Thank you for the encouragement you have been to me over the years, the blog has been a great way of "traveling" from one side of the world of the other even though it has mostly been through words and pictures!
Kind Thoughts to you and Gary,
Peter & Laura
Hi Owen,
Good to year from you. It would be wonderful help if you could do a test of the matte glaze in reduction, it will be very interesting to see how it turns out. I would expect a slight satin sheen in reduction, and it might give a grey celadon over an iron bearing clay. I have been glazing some more bowls with the same glaze this afternoon for a firing in the electric kiln. All going well, I will find the time to do the brush decoration tomorrow.
Happy New Year to you,
Peter
Thank you for you reply. I'll give the new glaze a go, and experiment with a few colours and I will indeed let you know how I go.
I tried yesterday to post a photo here of some test mugs I made with your green/blue flecky, but had no luck. When I figure out how to do it, I'll have another bash. You said in a previous post that you only need a couple of good glazes, and I think this one will be one of mine (especially since I mostly make unglazed non-functional stuff). It has such a lot of movement and interest - the almost violet speckles running through it are lovely. It's actually the first glaze I've made that I've really liked, and I can now see why people get hooked on the whole voyage of discovery with glazes. Thank you once again so much for your generosity. I know I'm not the only one who appreciates it.
Thank you for the lovey comment, I'm glad that you are enjoying the green/blue glaze. It would be great to see some photos, but I don't think it is possible to send such things via the comments section of the blog. You are most welcome to email me and send them that way. You should be able to track my email address down in the Contact page of this blog.
Do let me know how you get on with the matte glaze and with any colours you try, it will be very interesting and helpful to see how it works on other clay bodies and with glaze materials from different parts of the world.
Best Wishes,
Peter
Lovely to hear from you. Do try the matt glaze, it has been working very well for me. I am interested that you do aboriginal design, and would love to see what you do. You are welcome to Email me with a photo of your work sometime. My contact details are on the Contact page of this blog.
Happy New Year to you!
Peter
Thought I'd report back on some test tiles I did, using your matte glaze with ingredients in the UK. I made one as per your recipe above, and added some random orange stain to another, and copper oxide to a third (at least I think it was copper oxide - I'm in London and away from my tiles at the moment). What I got was a transparent, shiny glaze which pinholed! Quite possibly I did something wrong, since I'm such a glaze duffer. The copper addition went a rather dull green, and the orange stain was actually quite nice if you weren't looking for an opaque matte! (not sure whether your original is opaque or transparent and because of aforementioned glaze dufferishness, I can't tell from looking at the ingredients). I'll have another go soon.
Hope things are well with you and that you're getting into your studio. You must be sliding towards Autumn there, whereas here we have a carpet of white snowdrops, with daffodils, primroses and bluebells all starting to peer above ground.
Thanks for the report back regarding the matte glaze. All rather mysterious that you got something shiny and transparent... I don't really see how that could happen if glaze ingredients were of correct variety and weight. I had a slight panic when I read your comment as I wondered if I had made a x10 typo with one of the ingredients, but they all are as should be.
I made a big error myself today when making up a glaze, in that I weighed out 10 times the amount of the first ingredient (spodumene in this case) and blearily wondered why I had so little left in the bag. Fortunately the penny dropped before I added the second ingredient, and I was able to sort things out with no damage done!
We had a really hot day here today, fortunately my studio is in the shady side of the building so was able to occupy it and feel very thankful for somewhere that wasn't boiling! The cats are not very impressed by extremes of weather, but Nigella Stopit makes use of a large shallow stoneware bowl that is out by our back door, and fits herself into it. I guess that it is reasonably cool!
We are at the "overblown" end of summer where the days are shortening, and the birds are full of plums! Autumn not in sight as yet.
Snowdrops, daffodils, primroses and bluebells do sound very nice indeed!
Best Wishes,
Peter
I re-made the glaze, and curiously it turned out the same as before, ie pinholey, transparent and glossy! I do know I'm not the world's greatest glazer (to put it mildly), so it's quite possible I've stuffed up identically twice. Or possibly the different ingredients here affected the glaze so utterly that it bears no resemblance whatever to yours?! So I'm still on the hunt for a S/W matte that I can colour... (it's a useful diversion from the hand building I 'should' be doing but have hit a wall with).
I hope Autumn is progressing apace there and that you've got some relief from the heat. Here Spring bulbs are spurting out of the ground with what I fear might turn out to be ill-founded confidence since we haven't really had Winter proper yet.
All the best.
How sad that the glaze isn't working for you for some reason. Interesting that the same thing happened twice in a row, so not likely to be a problem with weighing an ingredient. I did have lengthy correspondence a few months ago with someone who was trying one of my other glazes and, after many repeat tests, did finally discover that one of their glaze ingredients had been wrongly labeled (Reminds me of an old song that had a line in it "What he thought was H2O was H2SO4"!). I suppose that there is no chance that one of the white powders that you are using is something like Lithium carbonate instead of Whiting? Or a high Sodium frit, such as 4110 instead of Soda Feldspar? It really does seem from your description like the glaze has been contaminated by a powerful flux of some kind. Lithium carbonate or a Sodium frit would give a result like that.
We currently enjoying a small crop of home grown potatoes, and are looking forward to a crop of pumpkins in a few weeks. The potatoes were more entertaining than anything else as they flowered very prettily, but were rather lacking in motivation when it came to actually growing potatoes in any quantity!
Hope the Spring bulbs bloom cheerily!
Best Wishes,
Peter
That took a while, mate. The North was full of Auckland TYPES, so I'm on Phillip island.. Which is full of melbournites, wallaby, and PENGUINS. Found the nice clay.. Again.. Box of fibre and glaze suff arrived last week, shelves full of bits, so no excuses! Gooseneck pottery.. Worth a look on the Web. I may be assisting in the winter firing by crikey. Proper pottery.. Oooo. Give the Mrs a squeeze from me.. And one for yourself as well. Cheers
Wonderful to hear from you from that hot, dry land of the fly just over the horizon! I'll peer at Google Maps and locate Philip Island. Delighted that you are potting over there and helping Gooseneck pottery on a winter firing would be great fun. I'm not far off cranking up my wood fired kiln again after rather a long break. Lots of pots to glaze that are on my shelves in the studio, and it would be really nice to fire them "properly" for a change with real flames rather than glowing Elephants... or what ever those wiggly things in the kiln are called!!
Had some great help recently stacking firewood, so no excuses!
Laura sends greetings!
All the Best,
Peter & Laura && Feline assistants!
Little glaze test firing yesterday.. The standard J D boos wonder..
All good..
No excuses.. Pots.. Seals. dry. Build kiln. Yes, fear not the flame. Wheee
Sarah Geary says hello. (I put up the munitions factory shot) I think she recognized the lovely pot belly etc in background.. Cheers
Have fun!
Peter