I wrote a while back that, for my first pit firing, I got some very nice fuming effects from a disemboweled Chore Boy type copper scrubber; but I was unable to reproduce the same effects ever since. Well, at the most recent firing I finally managed to get similar colors (and then some) with the same setup — and so here is the report…
I had seven pieces in this firing, two of which were intended as Chore Boy experiments. The first is a small pinched pot (figure 1 above) with two layers of packing materials, both very tightly wrapped around the pot:
- Chore Boy-type copper netting (one single layer)
- salted raffia (thin layer)
The feathery, wiggly lines in the deep red area apparently came from the copper netting that had started to disintegrate in that area. What’s unclear, however, is whether the larger, solid, and brighter red area to the right also came from the same. Or maybe it came from the admittedly plentiful copper carb in the pit instead?
As I have been looking for an alternative way to get a deep red without using copper carb (which is quite toxic), I was hoping that Chore Boy could generate enough deep red fuming on its own. While I am still unable to prove this conclusively, in figure 2 above we can clearly see the marks left by the copper netting with indisputable red as well as orange colors. So at least we know it’s capable of generating these colors.
Here (figure 3 above) is the bottom view of the same piece. Something about the orange color here: I usually associate orange color with fuming of salt or other sodium-bearing compounds (e.g. baking soda), but here the orange color seems a shade deeper and also appears to be somewhat metallic looking — so I’m inclined to think it came from the copper netting rather than from the salt in the raffia (especially since I had only a thin layer of raffia on the outside, while the entire surface of the pot was directly and fully covered with the copper netting. )
The other piece that I had in this pit doing the Chore Boy experiment (figure 4 above), like the first piece, got the nice red, orange, and blue-gray flashes, too; but it also shows what I’d see when I tried but failed to get the nice colors — just black or gray netting marks (figure 4 above, left side of pot).
Another view of the same piece shows the same good range of fuming colors as the first piece, except here we seem to be getting more subtle grays that verge on being green, blue, or purple-ish (figure 5, above). Unfortunately, this pot also has a very serious terra sig peeling problem — which, besides being unsightly, makes the job of analyzing what causes what more difficult. Incidentally, packing materials for this piece is as follows:
- “Chore Boy” copper net (1 single layer)
- salted burlap (1 layer)
- salted raffia (1 thick layer)
So, compared to the first piece, this one had much more salted material, and it probably experienced more of a mask/saggar effect — from the more substantial outer layer of burlap and raffia — too.
The bottom view (figure 6) of this piece is quite interesting and shows the form of the netting very clearly. Indeed this is one of the main differences between this and the first piece — here the markings on the pot reflect the netting form more clearly and more faithfully.
Okay, now we’ve got the Chore Boy to fume the way I wanted, finally. But what did we do right this time? Good question. I think we had a hotter fire, and had a lot more hot embers around the pots throughout the firing — but frankly, I am not sure whether these were indeed the real reasons for the success. Nevertheless, it would still be a safe bet that I’d go for the same kind of hot fire (and with lots of wood to create lots of embers) again next time!