I have to first of all apologise to my non-potting readers, this publish is going to be mostly glaze stuff. recipes and so on! However, you will see pictures! And you will like a consider the items in my glaze bucket. since we have been buddies this lengthy!
PTM
Potash Feldspar 41
Ball Clay 13
Silica 13
Talc 10
Bone Ash 13
Red Iron Oxide 10
+ Dolomite 11
+ Lithium Carbonate 2
The glaze I understand as PTM had its beginnings inside a Mike Bailey and David Hewitt recipe that seems within the book, "Clay and Glazes" (edited by Emmanuel Cooper and Eileen Lewenstein). My potter friend, Peter W. had attempted it a couple of in the past. Peter put together all of the figures within the recipe, and accidentally added some dolomite to his test. The end result was very promising, and compared to original, so he did a number of tests with growing levels of dolomite. I usually loved the feel of the glaze tests he did, and lent Peter's recipe and attempted to duplicate Peter's results. My tests looked, OK, the glaze was excellent, but were missing something, and that i began to suspect that the inclusion of Lithium Carbonate may help. A trip to Peter W. confirmed the original recipe must have had Lithium Carbonate inside it. An additional batch of glaze is made up, and also the tests with added Dolomite and Lithium look excellent indeed.
Close-up of PTM after some brushed on swirl of dolomite and water that gives extra fluxing.
Things I like about PTM, is it's a little "wild". It moves and changes colour as the story goes from thick to thin. Tossing rings appear well, and shut to, or under magnification, the color is extremely complex, showing flashes of plum, tomato, blue, orange, and brown.
I additionally tested Bailey's Red. which i present in John Britt's excellent book, " The Entire Help guide to High-Fire Glazes". Only now, like me penning this, will i understand how carefully the recipe resembles PTM. It makes sense quite different though, in colour as well as in character.
Bailey's Red fired at cone 9.
Bailey's Red
Custer Feldpar 47 (I made use of potash feldspar)
Silica 13
Kaolin 13 (I made use of ball clay to assist lower the fermentation temperature)
Talc 10.5
Bone Ash 14
Lithium Carbonate 2.5
Red Iron Oxide 8
Close-up of Bailey's Red.
Bailey's Red is really a lovely glaze, the gloss is even, the color even too. It is extremely interesting close up, being comprised of eco-friendly and red flecks, similar to searching in a pointillist painting completed in two colours. I can tell the red would develop better when the glaze were thicker. Another factor that will probably improve Bailey's (and most likely PTM) will be a temperature soak at approximately 950 levels Centigrade (1742 F) because the kiln is cooling. This could give a way for a few of the iron to re-oxidise. Within the situation of Bailey's this could lead to less eco-friendly flecks and much more red.
Although I consider it.
Some Suggested Studying.
I've lately been studying a variety of helpful reasons for using iron in glazes, and, for individuals wanting more knowledge of may be, I suggest a glance at this short article from cone 6 containers iron glazes and having red.
O ther experiments within this firing were with tenmoku glazes.
Dud mugs are actually excellent glaze testers.
One would be a Black Tenmoku that I have tried personally when firing to cone 11 or 12 within my wood fired kiln, but haven't done much with in a humble cone 9 within the electric kiln.
BTM
Talc 15,
Wolastonite 15,
China Clay 10, (I made use of Ball Clay)
Silica 15,
Potash Feldspar 55, (I made use of Nephaline Syenite)
and red iron oxide 8.
Substituting Nephaline Syenite for that Potash Feldspar and Ball Clay for that China Clay should drop the fermentation temperature just a little, which is things i attempted.
BTM with red iron oxide.
At cone 9 the modified glaze were built with a satin gloss, that really was rather nice, but it didn't develop its full black and extremely wanted more heat to do this, or requires a further adjustment from the recipe. I additionally tested this glaze with iron sulphate instead of iron oxide. Iron sulphate has got the lovely name, crocus martis, and that i desired to compare it alongside with iron oxide inside a glaze and find out basically could identify a positive change.
BTM with crocus martis.
There's one, which is very subtle, and that i find myself preferring the glaze which contains crocus martis, there's only a hint more warmth, and also the beginnings of the red/brown change of colour in which the glaze is actually thin. I additionally attempted the glaze with half the quantity of iron, 4 %, to determine what colour that will give, and it was rewarded with a yellow-eco-friendly brown.
I additionally fired something which a recipe Peter W. had as Red Tenmoku.
Not necessarily sure why it will get the name "red" because the glaze is an extremely brownish to black usually. This matured perfectly at cone 9, and is an extremely presentable brownish glaze having a slight reddish "break" in the rim of the mug in which the glaze is thin.
Red Tenmoku
Potash Feldspar 50
China Clay 10
Whiting 5
Dolomite 15
Silica 30
Red Iron Oxide 8
Both black and also the red tenmoku glazes are great candidates to be used being an under-glaze when you are performing chun type glazes.
Footnote.
Tenmoku, Temmoku. there are numerous spellings with this glaze. Regarding the concept of the term, "the attention of paradise" may be the and therefore I've heard most frequently, however i will give you a hyperlink to some site which has several more explanations from the word. Tenmoku meanings .
Errata. I attempted to publish just a little video about this, but needed to remove it again because the seem got all messed up "somewhere within the cloud"!
Hi Meredith,
I truly will sail across to NC, there'd be a lot to speak about. Very beginning for me personally so far as my very own efforts with iron reds goes, however i love the couple of examples that I've come across. I believed that iron reds may need plenty of heat to operate whatsoever, however this, thankfully, seems not is the situation. I've got a strong suspicion that the really fine tenmoku may need it hotter though. The influence of hard brick and slow cooling on glazes is interesting too. My wood fired kiln certainly improved with time too, most likely because of a sluggish develop of natural ash glaze around the bricks.
Hi Linda,
I'm missing reduction glazes too a little, those about this publish counseled me oxidised within the electric kiln. One factor I loved concerning the one out of the very first photo was how just like a real stoneware glaze it had been, in complexity of colour as well as in feel. Should you ever do cone 9 inside your kiln, you should attempt it sometime.
The pit firing idea sounds great, and I think you'll have that done. It might be great with a few of the work. It is good so that you can make a move with a few real smoke and flame!
Hi Patti,
That's so sweet! xxx!
Hi Gwynneth,
I've one without Li which i combined with success previously at cone 10 and above, it gave a powerful orange red having a more dark break. You may just get results in the cone 9 flat that you simply fire to if putting it within the hottest a part of your kiln.
Soda Feldspar 50
Silica 20
Bone Ash 10.5
Whiting 6.5
Ball Clay 7
Talc 6
Red Iron Oxide 11
I fired it in the electrical kiln as well as in the wood fired, with OK, but wood fired better with a few plum like crimson tones increasing the orange-red.
Unsure in case your desire to do without Li is really a safety and health factor, or if it's the price. (both significant worries within this house-hold!). I wish to try redoing the glaze using Petalite to exchange a few of the feldspar and every one of the lithium. Petalite, as being a feldspar like rock which contains some lithium, it minimises any risks connected with handling lithium carbonate and is a pleasant method of achieving similar results.
Thanks, I'll be mixing glaze tests in a few days!
Edouarde Bastarache from Quebec has recipes on his blogs too. I attempted one further firing (around the small cup and saucer, I believe I published an image from it.)not things i expected, but really worth trying again!!
he's different blogs for various colours!
He's on clayart and it is an excellent source of information which help.
Nice publish Peter, and nice containers, thanks to talk about your recipes, I have no idea after i can use them, when i may visit the marketplace on this summer and august. Nice PTM, I've got John Britt's book, however i didn't try the recipes since they're cne 10 glazes. I didn't buy lithium carbonate, I be worried about some oxydes, when i work not far from your kitchen. I truly want to only use safe raw material.
Used to do try your chn on some bowls, and that i realy want to change my kiln since it slows lower too quikly. The exam was excellent, the bowls show many little pin hole, as on my small glazes, when applied thick.
Good luck for you, Laura and also the four legged buddies
Hello Pat,
Lovely to know what you think. Where would I do without the great cheer and kindness of Pat and Patti from Arkansas! Both of you make existence a lot better. xx
Bonjour Armelle,
I only say this with gray circles throughout my eyes. as I've been up every two hrs during the night firing the electrical kiln, which appears to become getting increasingly more that is similar to your one! My one really needs encouragement!
I additionally be worried about some glaze materials, and i'll try some additional tests with PTM to find out if I'm able to get results nicely with petalite or lepidolite, or spodumene, because these minerals all contain some lithium, but could be much far better to have in the home than refined lithium carbonate.
I question where individuals pin holes are originating from? They might be because of gas from the glaze material or - probably - from something within the clay the pot consists of.
Here are a few recommendations for eliminating pin holes. You might well have considered these already, however this may help someone! (Other potters studying this my possess some suggestions to try, and therefore are thanks for visiting send them in.)
If you're able to contain the peak temperature for fifteen minutes to permit a while for that bubbles to prevent and also to heal over.
You might try firing your kiln lower if you feel the high temperature drops too rapidly following the kiln has turned off. To achieve that you simply turn on the kiln again and choose a minimal setting. Ensure that it stays on low for that first 30 minutes for an hour after it's arrived at the height temperature, and also the kiln will awesome more gradually.
I additionally question should you might solve the pin holing problem in the bisque firing stage? Try firing the bisque firing slower, especially between 800 to 950 levels Centigrade to permit additional time for those organic matter to lose from the clay.
Laura states Hello and also the four legged buddies send purrs. NS hid a defunct mouse inside a box, along with a dead bird. I believe that Ginger root caught a button on her. I've come across him do that!
