Monday, 25 July 2011

Successful Raku Firing Weekend

I have been wanting to do a Raku firing for some weeks but just did not get a chance due to the awful, rainy weather we have been having or to other commitments. This weekend, I finally had the opportunity to do two. On Saturday as it was still raining, I decided to use my little electric kiln to fire several tall sculptural pieces and some pendants. I used sawdust alone as my reduction material this time as I wanted to try to achieve the best possible reduction on the feature 'copper matt' area on the pieces. I did get a better reduction, but this also meant that the 'white crackle' glaze did not turn out as white as I like, but saying that, I am very happy with the results. I am still trying to perfect the timing thing with 'copper matt' and I must say it is a challenge. Each time I try, I seem to learn a little more. Sunday's work I am yet to photograph, but I was pretty happy with the results of that which I fired in my ceramic fibre/wire outdoor kiln.  Planning to make some more of these sculptural pieces to take to local craft markets to sell once our weather gets a little better.

Raku Sculpture - White Crackle & Copper Matt Glaze

Raku Sculpture - White Crackle and Ancient Amethyst Glaze

Raku Sculpture - White Crackle & Copper Matt Glaze

Raku Sculpture - White Crackle & Copper Matt Glaze

 Detail of Raku Sculpture - White Crackle & Copper Matt Glaze

Detail of Raku Sculpture - White Crackle,  Copper Matt & Amethyst Glaze

Tuesday, 19 July 2011

Winter Blues & 'Three New Family Members'

Its a cold and rainy winter's day here in Appin Australia. One of my other loves is gardening and it is not gardening weather at all the moment. We have had some cold frosty mornings and the garden is looking a bit sad. I did manage to get out in the garden late last week to dig over our vegetable patch in preparation for planting. We are planning to get some 'zoo poo' this year to dig through, which we are told comes straight from 'Taronga Zoo'. Will be interesting to see how the vege's grow with it in the garden.
Also in our garden, we have a large bird avairy. We have just added to the family, three chickens that a friend kindly gave to us. They breed and show the most beautiful birds. I am so happy to finally have chickens again. They seem to be settling in very well and the other birds do not seem to be bothered by them at all.

A summery photo taken in my garden - 'Flowering Gum' 
'The Girls'

Saturday, 16 July 2011

Cone 6 Test Results

Below are the results from my first batch of Cone 6 tests. I collected a number of glaze recipes, alot from this site and from other sources. The 17 glazes I picked were used mostly in combinations of two, one base glaze and another over the top.
The 17 glazes used; Chris Harris Tenmoku, Licorice, Nutmeg (revised version), Waxy White, Floating Blue, Floating Red, Variegated Blue, Water Blue, Water Green, E C Wide Base Blue Matt, Speckled, Chrome Tin Red, Jen's Juicy Fruit (no colourant), Zinc Semi Matt Light Blue, Green Matt, Val Cushing Green Ash, Hannah's Fake Ash. I purposely chose a selection of matt, gloss and semi gloss glazes. The clay i used is a white earthenware that matures at 1180 deg c. My supplier who also processes the clay, assured me it would be fine for Cone 6.
As this my first time to really test a variety of glazes, I will tell you how I went about it, so that you can see how I achieved my results AND so that those who have more experience can comment / advise on what I can change in the future order to get better results.
Firing Info - I have a small, manual electric kiln, approx 40 x 40 cm. I used three kiln shelves, two large cones (6) one on the top and one on middle shelf. Cone on top shelf was touching toes nicely and middle cone malfunctioned as it lent on a test tilie when falling (silly me). I set my temp controller to 1220 deg c to allow for a soak at Cone 6.  I peeked in the kiln at the cone when pyro read 1200 dec c and cone had just started to bend. Fell within in the next 20 mins and kiln automatically shut off at 1220 deg c. Also, at approx 1020 deg c, I turned the kiln down in order to slow down the end of the firing to try to achieve about 65 deg c per/hr. Total firing time was 9 hours, which perhaps is a little slow? Pls let me know. I did not do a controlled cool as I had intended to do. My daughter was not feeling well that night so going out to the kiln to do this was not an option later in the evening. But at least I have tests now with a natural cool and next time I can do a controlled cool and will have a comparison. I don't know if it counts for anything but I read the temp inside the kiln the next morning and worked out that from the time the kiln shut off to the time I read the temp in the morning, the temp would have dropped at approx 93 deg c per hour (naturally, with all bungs in).
Observations - I feel that perhaps my bottom shelf may have underfired a little. Some of my test tiles looked a little matt that should have been glossier. I had a few blister/bubbles with a couple of glazes too. My nutmeg glaze turned out semi matt when i expected a gloss? Someone may like to enlighten me with respect to Nutmeg. Licorice seemed to give me overall dependable and nice results when used with other glazes. I had spread evenly the tiles so not to have all the same bases on the same shelf in case of a temp variation in the kiln. Perhaps some of my glazes where a little thin. I still have a list of other combinations I didn't get around to trying here.
Anyway, I will let you be the judge. Please let me know your thoughts as this is the best way for me/us to learn.

A - Chris Harris Tenmoku only
B - CHT then Waxy White
C - CHT then Zinc Semi Matt Blue
D - CHT then Zinc Semi Matt Blue then Hannah's Fake Ash
E - CHT then Water Blue
F - CHT then Floating Red
G - CHT then V C Green Ash
H - CHT then Chrome Tin Red (has little flecks of red that are hard to see) 

I - CHT then Variegated Slate Blue
J - CHT then EC Wide Base Matt Blue then Hannah's Fake Ash
K - CHT then Juicy Fruit
L - CHT then Green Matt

A - Licorice only
B - Licorice then Chrome Tin Red
C - Licorice then Waxy White
D - Licorice then Nutmeg

E - Licorice then Green Matt
F - Lic then Water Green
G - Lic then Var Slate Blue
H - Lic then Floating Red

I - Lic then Floating Blue
J - Lic then C Harr Tenmoku
K - Lic then Zinc Semi Matt Blue
L - Lic then Speckled

A - Waxy White only (slightly green due to copper floating around in kiln)
B - WW then Water Green
C - WW then Green Matt
D - WW then Floating Blue

E - WW then C H Tenmoku
F - WW then Licorice
G - WW then Zinc Semi Matt Blue
H - WW then Water Blue

I - WW then Nutmeg
J - WW then V C Green Ash
K - WW then Hannahs Fake Ash
L - WW then Chrome Tin Red

A - Nutmeg only
B - Nutmeg then Speckled
C - Nutmeg then Floating Blue
D - Nutmeg then Var Slate Blue then Hannah's Fake Ash

E - Nutmeg then Licorice
F - Nutmeg then Chrome Tin Red
G - Nutmeg then Var Slate Blue
H - Nutmeg then Floating Red

I - Nutmeg then Waxy White
J - Nutmeg then Jens Juicy Fruit
K - Nutmeg then Green Matt
L - Nutmeg then C H Tenmoku

A - Water Blue
B - Water Green (crawling?)
C - E C Wide Firing Base Matt (Blue) Sure its not supposed to do this.
D - Floating Blue
E - Jen's Juicy Fruit (no colourant)

A - Variegated Slate Blue
B - Same as above
C - Floating Red
D - Floating Red then Licorice
E - Floating Red then C H Tenmoku

A - Green Matt
B - Green Matt then Waxy White
C - Green Matt then Licorice
D - Green Matt then V C Green Ash

A - Chrome Tin Red
B - Chrome Tin Red then Hannah's Fake Ash
C - Zinc Semi Matt Blue
D - Zinc semi Matt Blue then Licorice
E - Speckled (nice Matt)
F - Speckled then Licorice (very nice, almost like a woodfired look i think. Close up next)

F - Two examples of 'Speckled' with 'Licorice' over top

A - Speckled over a Copper & Iron Engobe/Slip
B - Jen's Juicy Fruit over a Copper & Iron Engobe
C - Tenmoku over a Chrome Engobe
D - Floating Red over a Chrome Engobe
E - Nutmeg over a Iron Engobe
F - Variegated Slate Blue over Iron Engobe

Thanks... if you have any questions, please let me know. Jan