Just to be clear, "naked raku" does not mean I was dancing around the hot kiln in newborn attire imploring the kiln gods to bless the firing. Hmmm, way too cold for that. No, "naked raku" is a technique where the applied slip+glaze combo is not decorative but serves as a resist to prevent smoking. The slip is designed to not stick to the pot while the glaze is designed to shrink upon cooling and fall off the pot after smoking in the reduction chamber, thus taking the slip with it. When the glaze shrinks in the reduction chamber it creates cracks all the way to the body, where the smoke can get absorbed. From what I observed in the firing, the thicker the slip layer the fatter the cracks. Fascinating !
I was happily surprised when I took the two pots out of the kiln. Usually, the slip/glaze layer expands a bit creating an orange peel-like texture when it is ready to take out. With the recipes (Wally's resist slip) I used, that occurs at cone 016-014. My friend Lee said no more than 1375F. Well, I kept watching for that famous peel texture, up to 1500F ! It was a bit irregular, but nothing dramatic. I took them out and placed them for reduction. Ten minutes later, I opened the metal cans. The eggshell was almost all gone with beautiful black cracks. Oh I was so happy I almost cried !!! It worked !!!
But I did learn a lesson. Silly me, I used pieces that were neither burnished or treated with terra sigillata, and it showed big time ! You can see all the marks and crevaces on the surface. Even more pronounced after waxing the pieces.
Besides the "naked raku", I had several bottles that were treated with Hasselle's Copper Matte. I fired them a bit cool (1730F) and reduced them with isopropyl alcohol-soaked wood shavings. They turned out kinda blah. But then I played with them a bit with a torch, and voila ! Peacock bottles :)
|Peacock Bottles (Copper Matte)|
So much fun ! Next Raku firing is on December 5th, weather permitting. I started making some terra sigillata. More naked raku on the way !