As I mentioned in my first raku post, the “baked potato” technique involves coating the bisqueware in ferric chloride, sprinkling it with sugar, salt, and/or horsehair, and then bundling it up in aluminum foil like a baked potato before firing it. The one example piece we were shown of this technique was interesting but not super compelling, so I just tried two “baked potatoes” out in the form of a couple cache pots.
Interestingly, the resultant pieces did not come out as advertised, but I do really like how they ended up. I was told the sugar and horsehair spots would turn black, but on my piece they are mostly white with some grays. This could be for a couple reasons: A) all the environmental variables at play - the local temperature and humidity outside, the ferric chloride purity and concentration, the thickness and tightness of aluminum foil, etc. B) at the time I understood I was to put one bundling of aluminum foil on, but afterwards I heard that perhaps the instructions called for two. Reason B is all the more interesting because some of my foil burned off in the kiln, exposing part of the pottery inside. The kilns did not have organics inside beyond what was in the “baked potatoes” and had vents providing air flow, so maybe the burning of the foil resulted in less carbon trapping than would otherwise have occurred?
Due to the general inconsistencies and vagaries of raku firing and the complicating factor of my still not being sure how many layers of aluminum foil is advisable, I’m very unclear on if I can replicate the appearance of my “baked potatoes” in the future.
Here is my first “baked potato” cache pot. As you can see, it kind of looks like red marble or agate. I had the choice of sealing these pots with a gloss or matte coat. I chose the matte, which I stand by.
