Hello chemistry nerds!

I got into dyeing, first using commercial products, then experimenting with DIY vegetable-based dyes, because if there’s a more expensive and labour intense alternative to buying a ten dollar product, I’m all over it. Naturally, I started extracting lake pigments to make paints out of my used dye baths.

Before you say it, yes! I do want lower quality paints that fade faster and take two days to make.

I use alum (aluminium phosphate) and soda ash (sodium carbonate) to precipitate the pigment, followed by drying and grinding.

Since this journey began I noticed some dyes just won’t work for pigments. I tried hot, cold, waiting, stirring, light jazz, more acid, more base, but the bitches won’t precipitate. Cranberries were my most recent failed pigment (but they dyed real nice.) There was lots of colour left, and I even tried a new dye batch with fresh cranberries, but it had the same result.

SO! I’m wondering:

  1. What makes a dye substance a better candidate for a lake pigment? Are there chemicals the alum can latch onto easier than others?

  2. If alum doesn’t work, could a different metallic salt work better?

  3. Why does every blog say not to use your dye equipment for food? What if I clean it super well?

  4. Are there other chemicals I can try? For funzies?

  5. Are there any other cheap, convenient products I can replace with five hours of destroying my kitchen?

  • Wren@lemmy.todayOPEnglish
    2·
    2 days ago

    Amazing! This is more than I expected, thanks for taking the time.

    1. Super helpful. I have just enough chemistry know-how to understand. The resources I found were either over my head or not detailed enough, this is perfect.

    2. I’m gonna try ALL the salts.

    3. Good. Good to know. (oops)

    4. Like if grass is the best dye but Big Green Dye doesn’t want us to know. Or if there was a way to make red cabbage explode.

    5. Perfect. I already have a lot of leftover cabbage. I simmer it in salty vinegar water for a dye bath anyway. (Before I add the poison.)

    bonus: I’m gonna try both of these today.

    Thank you!

    Edit: Follow up question, if it’s not too much. Do you know if there’s something that makes certain dyes adhere to plant based fibres better than animal-based and vice-versa? My cabbage dyes suck for wool (even trying different mordants, including alum which, from my observation, sticks to wool and the dye stuff,) but adhere to cotton and rayon very well.

    • Wrufieotnak@feddit.orgEnglish
      2·
      2 days ago

      Glad I could be of some help.

      I’m interested to hear about your experiments.

      Regarding your edit: sadly no, that is outside of my expertise.

      • Wren@lemmy.todayOPEnglish
        1·
        1 hour ago

        I’m following up because you’ve been so helpful, and in case someone else has the same questions some day and sees this.

        I ran out of alum, couldn’t find any more locally, so I haven’t tried the alcohol tincture process yet with aluminum phosphate.

        However, when mixing the last of my alum with a blueberry dye bath, I had the same result as with cranberries. Makes sense since blueberries, cranberries and huckleberries are very closely related (I could do a whole spiel on that.) I tried boric acid with the blueberry dye — it just turned black and very opaque. I tried to dye with it but it wouldn’t take to wool (the only raw fibre I had available.) I read that it needs to be an aluminum salt, but I don’t know why.

        As luck would have it, I got the last bag of aluminum sulphate soil acidifier from a garden center before winter, and it worked to precipitate every dye I’ve tried since; blueberry, cranberry, cabbage, and carrot. Plus, it’s like ten bucks for 2kg as opposed to 200g of Alum at a pharmacy.

        I had a small test batch of blueberries stewing (low heat double boiler in a closed container) in 99% isopropyl, which the aluminum sulphate worked with as well. I kinda liked that it didn’t foam up as much as the water baths, but unless I get significantly better results it’s not worth it economically to use alcohol since I hooked up with my new main squeeze (aluminum sulphate.) It’ll be a week or so before I see the final pigment colours to compare.

        Regardless, I continue to science and learn. I have my own mordants going with copper and iron in vinegar, plus lichen fermenting in ammonia, which is supposed to make a dye that doesn’t need a mordant. I don’t know why.

        Maybe one day I’ll write my own blog about it.