I posted this on the 'Sustainable Natural Dye Practice' Yahoo group but I thought I would post my question here as well.--
I have a question about copper water. I have made several jars using some old copper wire and they always come out that lovely pale greenish blue typical of oxidized copper. I decided to start another jar with a piece of copper pipe and some older pennies. I thought I had used vinegar in the first jar so I put that in with water (1:1) and waited...and waited...etc. No color was coming so I opened both jars and smelled the contents and could tell I used ammonia in the first jar. I poured out the vinegar water and added ammonia water (1:1) and got an instant color change. Now after a week or two the color is a very deep cobalt blue. Does anyone know what is happening?
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the blue colour is evidence that some of the copper metal is being dissolved ie reacting with the liquid to form another compound
ReplyDeletethis method produces relatively weak solutions that will influence your dye colours towards green. i use home made solutions sparingly [a couple of teaspoons at a time with a lot of water] as pre-mordants or sometimes a post dyeing colour enhancer. more rarely these days as i'd rather just use windfalls and water [the KISS principle]
vinegar and ammonia are two quite different substances. the former is an acid whereas the latter is an alkali. ammonia produced by fermenting Y.O.U. [Your Own Urine] is weaker and therefore [i think] safer to use than the commercial kind. it's also free.
anyhow different pH and compositions will result in different colours of brews. [how i wish i had paid more attention in high school chem lessons!]
i wouldn't be drinking any of these brews AND i'd always wear gloves when using but they're certainly much less dangerous than tipping spoonfuls of copper sulphate into your dyepots
Thanks for the information India.
ReplyDeleteI wish I had paid more attention in chemistry too...all I can remember is the boys using the chem shower when the teacher left the room...naughty boys!
Not to worry,I thought I would pass on any drinking of these brews. I would much rather have brews made with fruits or grains.
I am wanting to get some greens...I have lots of yellowish tan pieces but I really like green. I get a nice green with the eco-prints but I want a large piece of green silk. I don't have a copper pot yet so I thought to try copper water. I have been using copper pipe to wrap things in and I thought if I added some copper water to the bath it might green-up things.
Undaunted I will keep try(dye)ing.
Post 1982 pennies are copper plated zinc not pure copper like your wire. That could account for the color difference since worn pennies would have exposed zinc.
ReplyDeleteIt's been so long since I did a "penny bath", I likely had a preponderance of pre 1982 pennies ;-)but I do remember green not blue! Also, did you rinse the pennies between the vinegar and ammonia? If not, then the pH in the wire jar is likely to be higher than in the penny jar ... another variable that coule affect the color.