Saturday, November 21, 2015
This was the first time I've used Brazilwood in quite some time and certainly the first time with this much variation in preparation and handling the pot. First I soaked the Brazilwood sawdust (3 oz) overnight in a nylon stocking to contain the chips/sawdust; then I boiled it for 1 hour. Then I added pickling lime, i.e. calcium hydroxide (about 1/2 oz), plus a stick of ground up chalk to a pot of hot water, and then the dye liquor and bag of chips. The pH at this point was close to 9.0. A mix of fibers was added (mostly wool), some of which had been pre-mordanted with alum or copper. Then the bath sat for about a month prior to being acidified with citric acid; interestingly I had no problems with mold growing in the pot during the month it sat idle. I did take the precaution of removing the bag of Brazilwood chips and letting it dry out after we had finished with the first basic pot, and then put it back in the pot just prior to acidifying the pot. The pH just prior to acidifying the pot was about neutral and after the addition of citric acid (~2 oz) it went to about pH 5. Below is a picture of the resulting wool yarns. From left to right, it is alum and copper pre-mordant with basic 1st pot, then alum and copper pre-mordant in the acidified 2nd pot. The two things that are most striking to me are the range of color and that their is very little apparent difference between the alum and copper pre-mordant yarns.