Raku Leaf Vase and Ammonite Vase

Here are a couple of Raku fired pieces that I made recently.

I used some leaves from my garden to make the leaf design on the front. It was made by wrapping a soft slab around a cylinder, then after removing the cylinder, I pushed the top together and pushed a dowel right through to make the hole. A base was added and impressed decoration once the piece was a little firmer.

To decorate, I brushed copper carbonate onto the bisque fired surface then washed back a little so that the copper carb remained in the textured areas. The whole pot was then sprayed with a 'White Crackle' and glazed and fired to 1000deg cent in my raku kiln.

Raku Fired  'Leaf Vase' with White Crackle glaze and Copper Carb detail

Here is another piece I call the 'Ammonite Vase'...



Raku Fired 'Ammonite Vase' with White Crackle and Amethyst Glaze





















Waiting for some fine weather to fire some more pieces that I have ready....

Mucking Around With 'Dry Glazing' Techniques - Cone 6

Dry Glazes and Engobes for Cone 6

This is obviously NOT to be used for functional pieces (for those that are new to ceramics), only sculptural pieces. Best when used over heavy texture, carving, sprigging etc and applying the engobe in varying thicknesses in combination with the dry glaze.

These recipes and techniques come from an Australian ceramic artist by the name of Simone Fraser. I have long admired Simone’s work. The recipes and techniques below were obtained whilst studying ceramics at Hornsby TAFE some years ago. Her website is well worth a visit to see some examples of how she still uses these engobes, dry glazes and techniques. http://www.simonefraser.com.au/

Step One - Apply Engobe to leatherhard clay over texture and bisque fire to Cone 06. You can cover the entire tile/piece or sponge back in places to reveal the clay body underneath, which gives you another variation (very nice).

I don't nearly have enough texture on these tiles for this to work effectively, but at least it's a guide. When heavier texture is used, it gives the ability to apply the engobe thickly and then remove some in the high areas giving better results.

Photo below is just to give you an idea of the colour of the engobe on its own after bisque firing. You can also add more oxide quantity to each engobe base than I have here. Additionally, you can make up other colours. Up to you. Test, test, test. The engobes don't look like much when initially fired to Cone 06 but at Cone 6 with dry glazes etc over the top, they work their magic.

Engobe Base Recipe

Eckalite                60

Silica                    20

Potash Feldspar  20

Bentonite              3

Step Two - After bisque firing the engobed tiles, I apply various oxides washes over engobes then sponge off/back in completely in areas to ensure that the underlying engobe is also visible.

NOTE: In all of the tiles shown here I have used a 'Rutile' wash (resulting in red) and a 'Manganese' wash (resulting in a metallic dark brown to black). You will notice that the wash is prominent in the deeper texture here but that is up to you. Also, other oxides work too. Again test.

When I was taught at college, we were only taught to use the engobe and dry glazes in combinations. I have found that adding the oxides wash just adds another dimension.

Step Three - I then sponge on the 'Dry Glazes' so that they appear on the very top surface. This allows the underlying engobe, oxide wash and clay surface to show through.

There are endless possibilities with this dry glazing technique. They can be sponged on, dipped, brushed on and then wiped back. I like sponging on or brushing using a stiff fan brush as it then just touches the surface as I am trying to keep the deeper texture free from glaze.

I have not covered all the variations as they are endless. I find that it works well to use contrasting engobes/oxides under the glaze to achieve the best results.

Here are 3 tiles and how I decorated each one. I see that I have alot of improving to do with this techniques, but trial and error is the key to success.  

Tile One

This tile has the following;

·         Engobe with 4% Chrome added to the base. Painted covering the entile tile.

·         Rutile wash on the left and Manganese wash on the right and sponged back lightly in places.

·         Cobalt Dry Glaze (Base with 2% Cobalt) sponged all over the very surface, making sure not to sponge in deeper textured areas.

Tile Two

This tile has the following;

·         Engobe with 1.5% Cobalt Carb added to the base. Painted covering the entile tile.

·         Rutile wash on the left and Manganese wash on the right and sponged back lightly in places.

·         Moss Green/Brown Dry Glaze (Base with 3.5% Yellow Iron Ox plus 3% Copper Carb) sponged all over the very surface, making sure not to sponge in deeper textured areas. Moss Green/Brown tends to be green where heavier and moss brown were lighter application is achieved.

Tile Three

This tile has the following;

·         Engobe with 8% Iron Ox added to the base. Painted covering the entile tile.

·         Rutile wash on the left and Manganese wash on the right and sponged back lightly in places.

·         Cobalt Dry Glaze (Base with 2% Cobalt) sponged all over the very surface, making sure not to sponge in deeper textured areas.

Dry Glaze Base Recipe

Eckalite 2                    23 (I think EPK would be a sub, as Eckalite is a Kaolin)

Soda Feldspar             16

Whiting (calc carb)     28

Molochite #200           23

Frit 4193                      8

Add; 2% Cobalt for Blue

         3.5% Yellow Iron Ox plus 3% Copper Carb for Moss Green / Brown

         6% Copper Carb for Apple Green (i did not have an example of that          

          variation above)

Reliable Cone 6 Glaze - Chrome Tin Red

Flower Sculpture Glazed in Chrome Tin Red at Cone 6

This flower sculpture was made some months ago now and intended to be used on a steel rod in the garden. However, it looks just a nice sitting on a table. I have glazed this piece using a Cone 6 glaze called Chrome Tin Red. Its one of the most reliable cone 6 glazes I have ever used and you can experiment as I have done, by over spraying with other glazes to see what happens. Here I have used 'Fake Blue Ash' and a glaze called 'Nutmeg'. I used a white earthenware paperclay from 'Blackwattle Pottery' located in Ingleburn NSW. John manufactures his own clays onsite and I have found them to be excellent. The white earthenware clay I buy from John are recommended to be fired to 1150 deg c from memory, but I find it fires to 1200c with no issues to date. I have also used his 'White Grog Raku' clay for my raku pieces.

Here is the recipe for 'Chrome Tin Red' Cone 6 Glaze' - sometimes known as 'Raspberry Red' or 'Burgundy Red'

 

Whiting                       21.00 grams

Gerstley Borate            8.00

Edgar Plastic Kaolin     9.00

Talc                              4.00

Custer Feldspar         31.00

Ferro Frit 3134             9.00

Silica                          18.00

Tin oxide                      5.00

Chrome oxide              0.2

Total                        105.20 grams 

		Here is another Chrome Tin Red/Pink glaze that is also reliable. 'Chrome Tin Red/Pink' Cone 6 (Glossy) Gerstley Borate            21.00 grams Nepheline Syenite       16.00 Edgar Plastic Kaolin    11.00 Whiting                        20.00 Silica                           32.00 Tin oxide                     05.00 Chrome oxide                0.2 Total                         105.20 grams
		No fussy around with the firing of this glaze and I have found that it fires well no matter what the firing schedule, but I would recommend a hold for 1/2 hr at around 900c on the way back down. I have even used this glaze in single firing with good results. Good luck and drop me a line to let me know what you think of this glaze.