Our friend Esmé creates gardens: many of the plants that she grows she uses for making fabric dyes. She has been researching natural dyeing since the mid 90’s, whilst living in South-East Asia, India, Bangladesh and Singapore. She now lives and gardens on Saltspring, cultivating dye plants that grow in our unique Gulf Islands’ climate, and her website can be found here.
The vital pigments & dyes can be extracted from the plants in a number of ways, and in the case of woad (Isatis Tinctoria ) and Indigo, it’s necessary to pound the leaves in order to break down the fibre and release the pigments; this can be done in a mortar and pestle, if you have one which is large enough………..
Esmé recalled seeing dyers in SE Asia using tall mortars made of logs, and we found some photographs on-line, which were African, and had nothing to do with dye-making:
……but the tool would serve very well.
Assuming that we had a section of log (not hard to find), how could we make something similar? (The difficulty is clearly with the mortar, and not the pestle.) Three possible solutions came to mind:
a) Turn it on a lathe.
b) Carve it.
c) Burn it.
Turning: this would need a rather massive lathe - for conventional turning, anyway. The blank that we intended to use was a fir log about 16” in diameter, some 30” long, and weighed maybe…eighty to a hundred pounds. While this may be all in a day’s work for the current generation of massive bowl turners, it’s entirely beyond my capability. Of course, that would be with “conventional turning”, where the tool is stationary and the wood moves—an unusual combination in woodworking. Somewhere on this site is a description of a hybrid turning method used to create a large globe, but I’m not sure that it would work for an internal hollowing. (The outside of the fir log can stay as it is, bark and all, and needs no turning.)
Carving: sounds laborious and barely possible, technically speaking. The hollow in the mortar needs to be about 18” deep, and I can’t see reaching that depth with conventional gouges and a mallet. On the other hand, an angle grinder with a chainsaw-tooth wood-carving disc might work…..
Burning: light a small chip and charcoal fire on top of the log, in a small hollow. Let it burn its way down, but do not permit it to burn its way towards the edge. More research suggests that coating the already burnt wood with clay might limit the scope of the fire; otherwise I remember reading somewhere that waterglass (sodium silicate) might do the same thing. (Waterglass is (or was) used as a fire preventive/retardant for wood.) Of course, this might not work as advertised, like cutting glass underwater with kitchen scissors.
To be continued.